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iATN Review: Newsletter for Members
First Quarter 2014 EditionWorld's First & Largest Network of Automotive Professionals
Table of Contents
Introduction
The Field Blotter Oil Testing for Objective Analysis and CYA
Don't be a Hero
Compression Waveforms, Part 13
Learning Difficult TPMS Sensors
Volumetric Efficiency
IMRC Bushing Install Tip
Pre-Ignition vs. Detonation
It's not all about fixing cars... other details matter
CAN Bus Diagnostic Basics
Battery Terminal Crimper
Duramax DEF and Nox Question
How to get correct and precise story from tech to invoice?
A TALE OF TWO CLUSTERS by Henry Ford
Hard to Find Electrical Problems
Intermittent Misfire at Idle

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A key benefit of iATN is the opportunity to continuously gain insight from your peers in the industry, and we're always seeking ways to provide that same opportunity to our future workforce: students. A few years ago we began offering a program to allow iATN members that are educators to invite their students to join iATN at a read-only level.

This month we have expanded this program to provide a greater value to schools. A single instructor at a school can upgrade to Business+ and provide premium access to every instructor and student at their campus. Premium access is controlled by the instructors, allowing it to be easily enabled or disabled for each individual student member in their program.

These students can learn by surfacing some of the same great information we highlight each quarter in the iATN Review, and gaining valuable perspective on challenges their peers are facing daily. We believe this will lead to a graduate that has a higher level of preparedness than one without this kind of access. And when they graduate, they can easily move to a full iATN membership, participating and sharing their knowledge as well.

On a personal note, if I would have had access to a resource like iATN in my time in tech school, I know that my early days in the shop would have been a lot smoother. For more info on this new program, please see our official announcement here.

And speaking of education, this edition of the Review is once again packed with insightful articles, including: some perspective from a tech turned service writer, compression waveform analysis, volumetric efficiency discussion, shop management insights, a tip on how to install IMRC bushings, pre-ignition vs. detonation, CAN bus diagnostics, Duramax DEF & NOx, technician communication and more! We hope you enjoy.

Regards,



Scott Brown
iATN President

Full Article


The Field Blotter Oil Testing for Objective Analysis and CYA
Technical Tips Forum
Norris from Colorado

Vintage Blotter TesterBlotter Test In Progress
This idea has been around for a long time, I believe it started in the steam shovel days of the Panama Canal. Equipment operators were given printed business cards made of blotter paper and instructed to "field test" the oil in their equipment on a daily basis. In the 1930's and this method was in wide use across the USA Vintage Blotter Tester.

There are commercially available kits available at your local parts store or online http://www.fluidtesting.com/

I started using the Fluid RX kit about 10 years ago and found it to be lacking in many respects. First off, the paper is too thin and smooth, I wanted something that was more absorbent and if chunks were present in the sample they would stick to the paper. Also they left out the idea of putting a magnet behind the paper, and the ability to send the sample along with the RO! So off to the art supply store, craft store and hardware store I went. Took a while to get it right, but here is what I came up with.

This paper works great Blotter Paper Part # Tag, cut to size Oil Test Card Dimensions, stored in a bin Bin Full of Test Cards and dished out for use on every car.

This homemade fixture is what I use to add the magnet into the test Oil Blotter Testing Fixture, it is made from a leftover 3M electrical tape roll box, with a chunk of foam cut to fit and a magnet glued into the center. I made a much more elaborate one for my buddy (Chip at Main Street Garage, Fairplay, CO.) out of an old wooden box, with the fixture and cards all in one place, maybe he will take a picture and post it up here.

Take the fixture over to the car, let a single drop of oil fall off the dipstick onto the card like this Blotter Test In Progress. With hot oil it will absorb in less than 30sec, and gives instant results for carbon chunks Oil testing for sludge, ferrous metal shavings Metal Shavings in Trans Oil, non-ferrous metal shavings Non-Ferrous Metal Flake, and water Water Contamination Frontlit, Water Contamination Backlit, and gelled oil Gelled oil blotter test. To get the soot ring to appear Soot Ring 15x Magnification takes longer, sometimes up to 8 hours.

Add a plastic baggie Zip Lock Baggie and it's ready to staple to the RO for CYA! Backlit Oil Test Sample Sealed

You might want to tool-up a bit for closer examination of the test samples. I now use a digital USB microscope Celestron USB Microscope because at a push of the button, you have a digital picture. If you buy one of these, don't let them fool you, it's NOT REALLY 10x to 150x magnification, more like 5x to 15x, but it still gets the job done nicely 1997 Honda Civic CX, Engine/Propulsion Photo

I also like the 6x lighted magnifying glass and 30X microscope Oil Testing Tools, for a quick look at the tool box.

So who's up for a little objective analysis and CYA documentation.

Objective Analysis Trans Oil Micronta 30x Magnifier Oil Test Samples Stapled Pile of oil blotter tests FluidRX Color Sheet Oil Test Sample 2010 Subaru Outback 2.5i, Transmission Photo

Full Article


Don't be a Hero
Shop Management Forum
Nathan from Pennsylvania

When I was a tech I wanted to fix everything... bring me the car that nobody else can fix, I welcomed the challenge. When I switched to a s/w I told everybody "yes, we can fix that." I would bring in anything, I loved the car that nobody else could fix. As years went by, I changed. I came to believe in things like gross profit, comebacks, net profit, and billable hours. I came to realize that being the hero that fixed that car... no matter what... was satisfying to my ego, but damaging to my paycheck. The same is true for a shop.

As a shop, there are a few things that are finite, things that you have a limited amount of and have to maximize. The two biggest are time and space.

You have approximately 40 hours per week per technician to sell, assuming you believe in a 40 hour work week.

You have x number of lifts in your shop, whatever that number is, it doesn't change easily.

One of the things a manager should do is maximize that time and space. Put your technicians in the best possible position to succeed.

That difficult driveability job where a tech has to spend 12 hours scoping sensors, road testing, tracing wires etc. to find out that the ground wire is broken can be a huge drag on the shop. Even if you do charge for every minute your tech is working on it, you've tied up a rack and a technician for a day and a half in order to have a gross profit of approximate 60% of your labor rate (I'm assuming that the guy who is doing this is your highest paid tech)

In that same 12 hours, your "a" tech could do several simple diagnosis, a timing belt or two, 14 brake jobs, rebuilt 2 rear axles, maybe fix 3 a/c systems, or whatever else. That same 12 hours could result in 16-20 hours billed out, plus an equal dollar amount of parts sold. Generating MUCH more revenue and profit for the shop.

Now, I'm not saying that we should never do anything difficult. There are many reasons to take on a tough job, often we don't know what we're getting into until we're past the point of no return.

We need to maintain a mix when we schedule work. We can't overload our A techs with the difficult jobs to satisfy our egos. We can't plug up our shops with headaches and nightmares while the shop down the street does the easy/profitable stuff and ships the tough stuff to us. I have no problem putting the headache on the back burner in order to knock out several profitable jobs.

One final thought for the shop owner who says "I'll just work on that one myself, then it won't affect my technicians or shops productivity..." This is only true if you work on that car at your house, during non-business hours. Otherwise, it is taking up space that can be used to make money, and it's taking you away from other jobs that you should be doing, whatever they are.

Again, there are good reasons to take on these challenges, but let's do it with our eyes wide open and recognize that they can be costing us money.

Full Article


Compression Waveforms, Part 13
Technical Discussion Forum
Shannon from California

2000 Volkswagen Jetta, CKP Sensor, CMP Sensor Waveform2001 Volkswagen Jetta GL, ECM/Inputs/Outputs Waveform
A 2000 VW Jetta is towed in for a stall, no start. Customer says it stalled suddenly, a few days ago, but restarted immediately. This time it stalled and would not start.

I scanned it and found some codes, most interesting among them was a 16725 (P0341) CAMSHAFT POSITION SENSOR IMPLAUSIBLE SIGNAL. I grabbed a Modis ULTRA and scoped the crankshaft and camshaft position sensor signals. Seeing both signals in tact gave me a pretty good idea of what the problem was. A quick search here on iATN turned up Michael Webb's contribution, which confirmed my suspicions. I didn't calculate the number of degrees the engine was out of time, but it certainly seemed like quite a bit.

I have no experience with broken/jumped timing belt issues on these engines, but they are apparently of an interference design. The engine cranking cadence was even, did not utterly lack compression, and was free of any horrible sounds. I thought I would use my pressure transducer and my Firstlook sensor and see what I could discern about the state of the engine.

I started here:

Cylinder #1 cranking compression with exhaust pulse waveform

I see a symmetrical tower and even exhaust pulses. I was looking for evidence of an asymmetrical tower, and/or any uneven exhaust pulses. I then swapped the Firstlook to the intake:

Cylinder #1 cranking compression with intake pulse waveform

There I was looking for any disturbance in the intake pattern, something like Matt Batulis's contribution.

I felt pretty confident that resetting the timing belt would get this engine running again, and that it would run well. My thinking was that I saw no evidence of compression leakage in cylinder #1 while using the pressure transducer, and both the intake and exhaust pulses were even. The intake pulses, in general it seems, are especially susceptible to almost any mechanical issue. Cranking, the exhaust pulses only seem to show pretty severe issues.

I contacted the customer and explained why the engine wouldn't start, what condition had caused this, and what the risks were in moving forward. The customer decided to speak with his wife, and do his own research. When he called back he was prepared to have the vehicle donated to charity. He felt the risk was too great to even attempt to re-time the engine. It was at this point that I went into detail on the pressure transducer and pulse waveform testing I did -- and how, while I couldn't guarantee the engine would be fine, I was reasonably confident that it would be. I was prepared to offer to re-time the engine for no charge if it proved not to work out, if he would agree to have us do the repairs if it did. I didn't need to, though, as he approved moving forward.

I lined up the crankshaft, and found out exactly how far off the camshaft was. The white mark is the timing mark, the green mark I made to clarify where the rear cover pointer was aimed. A closer look at one of my cranking compression captures in comparison to Kerry Marion's contribution shows the difference when viewed with a scope. The belt was tight and in tact, but I did notice the tensioner. I reset the belt position, using the existing tensioner -- which seemed to work well enough for testing purposes.

The engine fired up right away and ran very smoothly.

I took two more captures before I called to give the customer the good news:

Cranking compression capture

Running compression capture

Like I said, I've never run into an out of time 2.0 AEG engine before... and all I had to go on was that it was supposed to be interference. I felt approaching things as I did gave me enough information to feel confident in recommending the customer spend money by having me reset the timing. In the end I did give all the information I had to the customer, let them evaluate their tolerance for risk, and make their own decision.

Full Article


Learning Difficult TPMS Sensors
Technical Tips Forum
Andrew from Utah

I saw this in a TSB for an Acura and found that it works on other vehicles as well. If you are having a hard time getting your TPMS tool to activate the sensors on a particular vehicle there is a way around this. Find a deserted street (no other sensors around), drive the vehicle at 10 mph, while driving clear the TPMS codes and begin the learn process with a scan tool. All the sensors should be active when driving at 10 mph and quickly be learned.

DISCLAIMER I highly recommend having a copilot run the scan tool. Due to the random order in the learning this should only be done on vehicles where all the tire pressures are the same front to rear and shouldn't be done on vehicles where the tire position and pressure is reported on the dash.

Full Article


Volumetric Efficiency
Technical Theory Forum
Jason from Colorado

After having a discussion with the tech who attends my classes, it was apparent that he was struggling with the concept of volumetric efficiency. That got me thinking about something. Why do we still make references to volumetric efficiency of an engine? The volume is a constant. Do we call it volumetric efficiency simply because that's what we were taught and that's what we're comfortable, regardless of whether or not it is accurate or relevant?

Click here to read the entire discussion including 125+ responses.

Full Article


IMRC Bushing Install Tip
Technical Tips Forum
Mike from Ohio

2004 Ford Freestar SEL, ECM/Inputs/Outputs Photo2004 Ford Freestar SEL, ECM/Inputs/Outputs Photo
I was doing these IMRC bushings today and usually I drop a few. This time however Is the first time I actually believe there is just maybe slight proof I'm getting a "tad" wiser. Been using a pick with limited success.

I took this mechanics wire and ran it through the bushing,through the hole, and bent the end. Guess what I didn't cuss or drop one =) 2004 Ford Freestar SEL, ECM/Inputs/Outputs Photo 2004 Ford Freestar SEL, ECM/Inputs/Outputs Photo

Im a slow learner but if you're like me these little tips help out the day by just adding the slightest smile to your mug. I hope it helps you

PS here is the part number of the bushing in case your Ford place is like mine and every time its 5 minutes on the phone. I keep a bag in a parts bin now. 2004 Ford Freestar SEL, ECM/Inputs/Outputs Photo 2004 Ford Freestar SEL, ECM/Inputs/Outputs Photo

Full Article


Pre-Ignition vs. Detonation
Technical Theory Forum
Steven from Washington

I came across this article that explains the difference very well. Many techs use these terms interchangeably when they are actually two different things.

The first half of the article explains detonation and the second half explains pre-ignition. There is a lot of useful info as to the theory of these phenomenon, and the cause and effect.

http://www.contactmagazine.com/Issue54/EngineBasics.html

Engine Basics: Detonation and Pre-Ignition

Written by Allen W. Cline

Reprinted from Issue 54 of CONTACT! Magazine, published in January, 2000

Full Article


It's not all about fixing cars... other details matter
Shop Management Forum
Nathan from Pennsylvania

Lately I've been thinking a lot about details and how important the seemingly unimportant things are. Two things have really brought this to my attention.

The first is attempting to redo our shop website. In doing this I've looked at a LOT of websites, most of which are not in the automotive industry, I've noticed that little things like where a button is located or the background color of a page makes a big difference on how long I look at a page or how quickly I move on to something else. I'm sure I'm not the only one that is like that.

The second was going to brunch with my wife yesterday. We tried a restaurant that we've never been to before. It had good reviews, the menu looked interesting and the price was what I felt like spending. So we found the place and walked in. We were greeted nicely and sat right away. We ordered coffee and the spoon that came with my coffee was dirty. We ordered, ate, and the food was tasty. But the real kicker was there was no toilet paper in the ladies restroom. Bottom line.... The food was good but we probably won't go back because the restroom was out of toilet paper and a spoon was dirty.

Last week we did a great diagnostic repair. We were the second shop to fix a misfire, we repaired it properly for less than the first shop misdiagnosed it. The car also had a light bulb out. We replaced the brake light bulb and sent the car away. I got a call the next morning with the following complaint... "my car was there for 2 days and you didn't fix my brake light." I ended up giving away the circuit board that the car needed in an attempt to get that customer to give us a second chance in the future. But, she no longer remembers that we fixed her misfire, she only remembers that we didn't fix a brake light. Again, the details. We got caught up in the big problem, but all the customer remembers is the small problem we didn't fix.

Yes, fixing the car properly is important, but it is not the only thing. If a woman uses the restroom and it is dirty, does she leave your shop with a positive opinion? If you do the greatest repair in the world and leave a screw driver in the car, what does the customer remember? We did a survey a few years ago and found out that it was important to have a hook in the bathroom to hang your purse on. Not something that I ever thought about, but it was important to my customers.

What else do we not see that our customers do?

Full Article


CAN Bus Diagnostic Basics
Technical Theory Forum
Ryan from Illinois

I've gathered some information from several sources to piece together a diagnostic routine/guide for myself to use whenever I come across a communication error. Any input/critique is welcome.

#1 Double check that you have the correct vehicle info entered into the scan tool... it happens okay

#2 Check for data at the DLC using a scope. DLC breakout boxes are nice. Ive used AesWave's before and loved it. This will confirm no data transmission and eliminate the possibility of a faulty scanner. This could also narrow down which network you need to be concerned with.

#2.5 While you're there at the DLC, check for proper power and grounds to pins 16, 4 & 5. Some tools may require those to work while others may not. This is sometimes why one scanner will work and another may not.

#3 Try communicating with other modules. It is possible that the entire network is not compromised but only one module is down. this can be done using a suitable scan tool or by jumpering to the suspected modules. Depending on the system, this could be done easily at a splice pack or gateway module.

#4 Check the terminating resistors. Most of these(all?) have two terminating resistors in parallel to each other on each end of the network. Each resistor is 120ohms so when wired in parallel, will measure 60ohms.

#5 Check for TSB's. I've heard of vehicles where they needed a flash to solve the problem. That confuses me because if you cant communicate, how can you flash it? perhaps i wasn't told the whole story.

#6 Like for a lot of issues, check for any aftermarket equipment, modifications or prior work that could have been done by somebody less than professional.

#7 If one wire of the twisted pair has no data transmission, this is most commonly(not always) an issue with wiring and not a module.

On CAN LO, anything below 1.5v is a short to ground and anything over 2.5v is short to power

On CAN HI, anything below 2.5v is short ground and anything over 3.5v is short to power

If one wire is compromised or a terminating resistor is damaged, the noise on the lines will be greater than usual.

Full Article


Battery Terminal Crimper
Tool & Equipment Forum
Ray from New York

Battery Terminal CrimpBattery Terminal
Do any of you fine technicians know where I can source a battery terminal crimper that will make a crimp similar to the factory crimp as seen here? Battery Terminal Crimp

I did email DelCity who replied that they did not have a crimper to duplicate the crimp shown in my photo on this style battery terminal Battery Terminal

I do have the Snap-On Hammer type crimper, but it did not bend the ears over properly to emulate the factory crimp.

I do see that EZ-Red makes a battery terminal crimper, but I am not sure by viewing the catalogue pictures of the tool if it will make the crimp I desire.

I am thinking that the hybrid techs might have an answer due to the heavy wiring and connections that they have to deal with.

Thank you in advance for your suggestions.

Click here to read the entire discussion including 75+ responses.

Full Article


Duramax DEF and Nox Question
HD/Fleet Forum
Buddy from Georgia

I am working on a 2011 Chev 6.6 LML with 75,000 miles on it. It has a DEF Poor Quality message followed by a P207f code and a P20EE.

in reading GM Document on checking DEF specific gravity the statement is said DEF fluid pure concentrate should have specific gravity of 1.31 to 1.384 at 68 degrees.

Question 1; Have any of you guys been checking the specific gravity and getting 1.3 or higher reading?

I have done a DPF REGEN it made the NOX 2 sensor read 70% less than the NOX 1 sensor {it would not before REGEN}. It also fixed the NOX 2 sensor where it will go to 0ppm on hard decel.

This condition did not stay corrected for long after a few miles the NOX 2 Senor will not read 70% and the NOX 2 sensor will not go to under 94ppm on hard decel.

The poor fluid quality message has not come back on yet.

Question; How do you determine if you have a defective SCR or contaminated NOX2 ?

Click here to read the entire discussion including 20+ replies.

Full Article


How to get correct and precise story from tech to invoice?
Shop Management Forum
Ronald from California

I am anxious to see how other shop owners/managers handle this.

A chronic problem I have witnessed from the day I started working in dealers and then onto my own shop is a disconnect from the service bay to the invoice booker. How do other shops get a clear, well written, precise story from the technician typed onto the invoice that the customer understands.

When I was at the dealer it was written on the back of the RO by the tech and usually was a mess, incomplete and meant little to the office booking the invoice through. This was a problem with all the dealers I worked at and I recently talked to a good friend at a Chevrolet dealer that stated it is still a mess even though everything is much more computerized.

The obvious problems are, as I see them: Poor typing skills by many, poor spelling etc, lack of detail by techs(specific trouble codes listed) and a lack of knowledge of specific repairs in the office. I ran into this for years with a very smart and great office guy in the office. He was great with the customer's but had limited auto knowledge. I forever had to go and type in stories etc.

My solution came to me after some head scratching: We have a rear computer and a front computer both internet ready. I set up a gmail account where I can type out the estimate as it is made up to begin with. I set up a list of operation codes indicating to the office person when a new labor line is needed. I get it typed, sell the work, note the authorization times etc and then hit send. The email is sent to our own email address. She can access it up front and copies and pastes to Alldata. She can do this quickly. She can also verify the totals jive. This seems to work well. I have to do an estimate anyway, why not type it? If we need to revise, we just open a second email labeled REVISION. The customer last name, year, make and model are listed in the subject. With gmail, you can leave them in draft form if you are waiting on approval or feel a change may need to be made quickly. I have also found that it is handy when you have a vehicle come back in for a previous estimated repair. A quick gmail search with the name or vehicle brings it back up. And no paper laying around.

This is what I have found and it works good but I am wondering how others handle getting all the info from tech to invoice. Always like hearing good ideas and perhaps handing a good idea of mine on.

Click here to read the entire discussion including 65+ replies.

Full Article


A TALE OF TWO CLUSTERS by Henry Ford
Technical Tips Forum
Michael from New Jersey

Recent experiences with Ford Instrument Clusters.

First vehicle, 2010 Flex. Shop technician replaced Cluster with Ford dealer remanufactured unit. Replacement unit was already installed in vehicle when I arrived to program. Using ids with current software, I performed standard PMI from module programming menu. Straight forward programming, no options displayed. Did pats relearn, started vehicle. Immediate indicator lights: B2627 (fuel sender), C1415 (incorrect configuration) and U0102 (lost communication with transfer case module). Not good, FWD vehicle.

I then did the usual routine of reinstalling programming, same results. A call to the dealer verified that part was correct. The PMI was simple and straight forward automatic, no options or choices. There was an update to calibration (not configuration) for the Cluster, which I performed. (New part with out of date calibration.) No change.

Back to module programming menu, four choices including "AS BUILT". Having tried the other three options, I choose AS BUILT. The next screen gave a choice of "manual" or "automatic" programming. I chose manual, which required the customary internet look up, number copying and insertion in as built programming boxes. SUCCESS!, codes no longer present. The "AUTOMATIC PMI" option had lead me down the wrong road. I do not know if the reman cluster had any programming directions; the parts person at the dealership had removed ALL paperwork prior to delivery.

Tale Two, 2004 Focus, replaced with dealer supplied reman cluster. The replacement Cluster installed in vehicle before I arrived. A seemingly straight forward PMI, no options. Program and pats relearn and out the door. Except I now had the ABS light on, but the vehicle had no ABS. No menu option to use AS BUILT on the replacement cluster. OK, try again. The on screen instructions carried the usual procedure to start with original module. Yes, I usually ignore that instruction, do I really want to download info from a corrupted module? Well there was no other choice. Installed the original Cluster, gathered information as instructed on IDS page, replaced remanufactured unit and finished programming, abs light GONE. Once again the dealership parts person had removed all paper work from replacement unit before delivering to shop. Maybe explicit instructions were in the box?

Conclusion, no matter how many Clusters I have installed in 2002 Windstars, I will need to change my procedure to be successful with later models. To change the worst of times into the best of times, the original Cluster should be available to use for PMI if needed.

Full Article


Hard to Find Electrical Problems
Technical Tips Forum
Dan from Wisconsin

2006 Ford Escape XLT, Transmission Photo2006 Ford Escape XLT, Transmission Photo
I think one of the most important things NOT to do is move the wire harness when trying to verify the customers concern.

I am working on a 2006 escape 2.3 auto 4x4 with 60,000 miles.

Step one, recreate customers issue.

Step two, find the problem.

Step three fix the problem.

Step four, make out the bill.

The concern was reverse that would engage and disengage and a speedometer that at times would hang at 20 or 40 mph.

I got in the car with the scanner plugged in, put it in reverse to back out of the parking spot, as the accelerator pedal was touched it quickly disengaged and engaged the trans abruptly. My first thought was a broken or loose MLPS connector. I had one code p0707 I think.

The in and out of reverse was very very quick and harsh, so I was very careful moving it. I brought it in the shop to have a look at the connector and sensor. Nothing I saw looked bad or out of place, except the new MLPS.

I knew I was the third person to look at it for this concern. Now I have looked at the scan data for the mlps as I gently moved the connector and wire harness. Nothing shows up at all, remember I have tried not to MOVE anything without knowing that I did.

Next I try reverse and it works perfectly, no disengagement or speedometer issue. Now what did I do to change the problem? I don't know.

Now I walk away for a bit. When I come back I put my scanner pid on just the mlps voltage in graph form, move the harness and low and behold I have a zero volts on the graph for just one recording frame. The mlps must have a bad connection. No dice, everything is perfect. I start a new graph and realize that as careful as I am, my left elbow is moving the harness at the back side of the cylinder head.

Now I can recreate the problem with a gentle push on the wire harness that is 18 inches from the sensor. I found it, 2006 Ford Escape XLT, Transmission Photo 2006 Ford Escape XLT, Transmission Photo 2006 Ford Escape XLT, Transmission Photo

The learning curve is steep with electrical issues. Be very easy when moving something when trying to recreate the issue. Going at it, without knowing what you are changing always ends with, [can not duplicate customer concern]. Never good as the customer is looking at you thinking it does it every day for me.

Take your time and be very diligent with respect to knowing what you are touching.

Full Article


Intermittent Misfire at Idle
Technical Discussion Forum
Brandon from Pennsylvania

2005 Honda Pilot EX, Engine/Propulsion Waveform2005 Honda Pilot EX, Engine/Propulsion Waveform
I had some fun yesterday making some correlations for myself and proving-out some theories. I had the referenced-vehicle above come in to the shop with the complaint of a "rough-idle". The complaint was easily exhibited. The vehicle did indeed exhibit a misfire at idle. if the RPM was elevated even slightly, the misfire vanished. The vehicle did not exhibit the symptom nor any others at all, under any other driving-condition. I scanned the vehicle for DTCs...P0300 was the only DTC flagged. I referred to misfire-data and #2 was counting-up as well as #3. FREEZE DATA registered the same operating conditions. Fuel Trims were close to 1.0 off-idle but were as such during the idle/misfire:

LTFT#1=.93 (cyls 1-2-3) LTFT#2=.98 (cyls 4-5-6)

This vehicle had 150k miles on it and didn't appear to be properly-maintained. I had a strong hunch I was facing a valve-overlap issue. I thought it would be wise to take some BEFORE/AFTER captures using the First-look Sensor. I was hoping to see something on it. I connected to the intake manifold at the booster-port and referenced #4 coil-command because it was very easy to access.

[2005 Honda Pilot EX, Engine/Propulsion Waveform]

I removed the valve-covers to attain my measurements...I realized that the FLS was very capable of capturing slight-changes but I learned something today as well....if you refer to the actual-clearances on the right-side of the capture, you will see that the further the clearances deviate from spec, the more noticeable it is in the intake-waveform. I found that pretty interesting, myself. Below is the same waveform after adjusting the valves to proper tolerances.

[2005 Honda Pilot EX, Engine/Propulsion Waveform]

Im curious if anyone is familiar-enough with the ATS "H2O-sensor to explain to me how it would display the same waveform by comparison?....better-yet, does anyone have any of those waveforms that they would like to share so that we can all compare "weapons" of choice?

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