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Prev Professional Automotive Repair Technical Discussions for June 23, 2010
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Open Help Requests for GM
Help Request Answers
1997 Buick LeSabre Custom 3.8L centerline steering VIN: 1G4HP52K9V
Hello GM Techs. I am European specialist in need of some American advice. A family member's vehicle came in for routine steering/ suspension repairs. The steering wheel was a 1/4 off to the left before and after repairs. Attempted to perform 4 wheel alignment....
1994 Chevrolet S10 Blazer 4.3L Poor Idle Quality, Hesitation, Surge VIN: 1GNDT13W6R
I am testing this truck and have rulled out fuel pressure 55psi running, tried a know good injector, map sensor, tps. What i have is a lean condition just off idle. the truck will surge badly just as you bring the rpms up, corresopnding with this the egr and e...
1995 Chevrolet K2500 Suburban 7.4L Excessive Emissions, Poor Idle Quality, Hesitation, Cuts out, Misfire VIN: 1GNGK26N9S
This Suburban when started cold or just setting for an hour or so, will run bad. It runs like the egr is open. Surges up and down backfires, rough idle. No codes and the funny thing is when it is having this problem the data stream has some issues. Engine cool...
1997 Chevrolet Cavalier 2.2L Engine VIN: 1G1JC1242V
This is my personal vehicle. I did an engine swap to this cavalier about 2 years ago. It now has a 3400 OHV V6 out of a 2002 Grand Am GT. Dyno tuned. It has bigger fuel injectors out of a Trailblazer, and stiffer valve springs. The car has ran great for the pa...
1999 Chevrolet Tahoe 5.7L Poor Idle Quality, Hesitation, Surge, Cuts out, Stall, Misfire VIN: 1GNEK13RXX
Customer brought vehicle in complaining of missfire and back-firing first thing in the morning, after engine warms up vehicle is fine. No CEL's. Let it sit over the weekend and vehicle would not start unless holding throttle 50%. Installed fuel pressure gauge ...
2002 Chevrolet Express 3500 5.7L Hesitation, Misfire, MIL Lamp on VIN: 1GBJG31R92
This van came to us from a fleet customer that does most of there own work. Had code p0335 for crank sensor and would not eccelarate. Customer installed new crank sensor. Checked ignition componants and found in need of tune-up. problem still exists. In park i... Trouble codes: P0335 (CKP sensor A Circuit fault)
2002 Chevrolet Silverado 2500 HD 6.0L instrument cluster VIN: 1GCHK29U52
I have a instrument cluster with a PRINDEL that lights up intermittently only when the key is in ACC position. As soon as you start vehicle it blacks out. No speedometer, no PRINDLE, no tach, oil pressure, and no trans temp. Fuel Gauge and temp appear to be wo...
2003 Chevrolet Tahoe LT 5.3L MIL Lamp on VIN: 1GNEK13Z73
This vehicle has been at my shop for more than a week now and I'm yet to fix it. I have much other work to do & this one needs to go and its one of my better customers so any help would be greatly appreciated. The problem is intermittent but when driving down ... Trouble codes: P1516
2005 Chevrolet Silverado 2500 HD 6.6L Head Gaskets VIN: 1GCHK23245
We're replacing head gaskets with the updated ones on the 05 Duramax. I need to determine the thickness of the original gaskets using indicator holes in the gasket. I see 2 holes in the end of the gasket that are about 5/16" in diameter. These holes protrude f...
2005 Chevrolet Silverado 2500 HD 6.0L vent temp VIN: 1GCHK29U65
cannot get lower than 70 f at idle[95 ambient]50 f at 1500 rpm's.all blend doors full cold, system rebuilt using ac delco parts, extensively flushed.all lines, cond,evap clear. Anyone have any ideas or seen this before?also 40 degree drop across cond.
2006 Chevrolet Equinox LS 3.4L Poor Idle Quality, Hesitation, Cuts out, Stall, Misfire, MIL Lamp on, Cooling fan inop VIN: 2CND123F86
Thanks in advance for any help on this one. This came in with: Check A/C - does not cool at idle, while driving its fine. Found fans inop. Vehicle is overheating - although that wasn't one of the complaints. Vehicle has poor idle quailty, fans inop., stalls, d... Trouble codes: P0030 (p0036-), P0036 (P0201-p0206-), P201P, P0230 (P0442-p0443-), P442P, P0449 (Several others)
2006 Chevrolet Colorado WT 2.8L Vibration VIN: 1GCCS14816
This truck has a vibration that shakes the exhaust apart. Two mufflers have broken off and been covered by warranty. This was followed by several aftermarket mufflers at muffler shops. It has shaken the insides out of the rear converter and broken the weld at ...
1989 GMC G3500 Magnavan 7.4L add on overdrive VIN: 1GBKP37W4J
The customer recently purchased this unit out of state, sight unseen. He realised on the way home that the overdrive does not shift. This is a Doug Nash unit. In trying to research it, I can find info on the Corvette version but not this unit. It looks a lot d...
1991 GMC Tracker 1.6L No Start VIN: 2CKBJ18U4M
vechile towed no start no spark no fuel rattle from under dash like relays direct hit had several replies ecm failures followed test procedure needs ecm talked with customer this is the third ecm in the last 100 000km what is happening to these ecm??? is there...
2001 GMC Savana 1500 4.3L Misfire, MIL Lamp on VIN: 1GTFG15WO1
Thanks in advance.I have this savana 1500 van with 4.3 that is missing under a load between 3500 4000 rpms runs fine under light load and at idle.1 have replaced crank sensor twice,full tune up,fuel pump,distributer,coil and ignitin module.i have checked all c... Trouble codes: P0335, P1381
2003 GMC Sierra 1500 SLE 5.3L Drivers Information Center VIN: 2GTEK19T13
This is my own truck so I know its history. I simply parked my truck in my garage for 10 days when I went on vacation and when I got it out it was switching from Spanish to french to English on its own, also switching from odometer to trip to hours on it own. ...
2004 GMC Sierra 2500 HD 6.0L Temp VIN: 1GCHK29U54
I would like to know what temp other trucks like this one runs with trans temp gauge ?? are we running to hot.
1973 Oldsmobile Cutlass Supreme 5.7L ac VIN: 3J57K3R167
Hey guys this is a good one for me. Our customer brought this 73 olds in for tune up and re-install his ac compressor which was taken off along time ago. I installed compressor did retrofit flushed all the lines I could. The condensor lines are frozen so they ...
1991 Oldsmobile 98 Touring 3.8L No Start, Hesitation, Cuts out, Stall VIN: 1G3W53LOM4
This car has an intermittent no start condition. When it does run, it idles OK but it won't rev up without hesitating and cutting out. I drove it around the lot and into the garage and now it won't start. I hooked up my snap on scanner and I am not getting any...
1998 Pontiac Sunfire GT 2.4L Excessive Emissions, Poor Idle Quality, Misfire, MIL Lamp on VIN: 1G2JD12T9W
Vehicle came in with a bad misfire, P0300,swapped out the complete coil housing (coil housing, coils and ECM)- used- no change. Realized #1 injector was firing slower than the others, and at that time seen on the genisys that "output driver 2 open" was showing... Trouble codes: P0300 (Random misfire)
2001 Pontiac Grand Am GT 3.4L coolant fans VIN: 1G2NV52E81
Hello, Coolant fans do not come on and vehicle over heats, both fans work with ac and temp will run normal. Genysis scan tool will turn on low fan but not high, last shop added a ground wire to fan relay number one with a toggle switch for the customer to cont...
2002 Pontiac Grand Prix SE 3.8L air flow VIN: 1G2WP52K92
2002 grand prix with very little air flow in the hvac system. Blower works great, switches thru all of the modes. Pulled the blower but no restrictions. All acuators seem to be moving. Very little air comes out of any of the vents. Has anyone ever ran into thi...

Fixes & Summaries for GM
Fix/Summary Answers
1991 Buick Century Limited 3.3L Stall VIN: 1G4AL54N5M
Well, we received many worthy repiles from tap testing the ECM to chafed wires under the alternator. Many suggested testing the injectors with an ohm meter. Ohming the injectors is what we did. Four were at 12-12.5 while the other two were at 7 and 9. ...
1991 Buick Riviera Luxury 3.8L No Start VIN: 1G4EZ13L4M
Thanks all who replied. Many hit the nail on the head. I removed the new balancer and compared it to the old one. The "new balancer" was "clocked wrong", the 18x signal ring was off just a bit to one side.(Would explan why the signal looked good, it was a goo... Trouble codes: 41 (Cam Sensor).
2002 Buick Century Custom 3.1L abs VIN: 2G4WS52J12
Ok a big thank you to all those who took time to respond, most refered to the wire harness section that is refrenced in a tsb (sorry I don't have it at the moment) and so I called our local gm dealer and ordered the harness for the right front wheel speed sens...
1970 Chevrolet Corvette 7.4L rear camber VIN: 194370S412
Wow! 21 responses! Thank you all for your thoughts. What we found was that when the rear was rebuilt there were washers installed between the adjustable bushing and the mount. The bushing inner sleeve has "teeth" that help keep it from sliding when it is tight...
2003 Chevrolet Silverado 1500 4.8L a/c clutch diode VIN: 1GCEC14V73
2004 Chevrolet S10 LS 4.3L security VIN: 1GCDT13X84
thanks for the replies, i know your time is of value. i did receive a few good leads but the owner who is doing the legwork hasn't followed through on them. after posting, i did take a look at the vehicle, particularly under the dash drivers side. the female c...
2000 GMC Savana 2500 5.0L no power VIN: 1GKGG25R5Y
when the vcm was removed there was a gap between the two halves of the vcm. a new vcm was installed and the van runs like a top. THANKS FOR ALL THE REPLIES.
2000 GMC Yukon SLT 5.3L compressor VIN: 1GKEC13T2Y
Well this yukon is fixed gary from texas hit it on the money i was highly suspicious that it was the throttle body causing all this since sometime would idle so low and luck has it i had the throttle body sitting in my shop from an engine swap i had done in th...
1996 Oldsmobile Cutlass Supreme 3.1L Poor Idle Quality VIN: 1G3WH52M2T
Thanks for all the quick responses. Most of you said intake gaskets. That was it. Car runs like new. Thanks again. Trouble codes: P0507 (Idle control system rpm to high).
1998 Pontiac Grand Prix GT 3.8L Surge, MIL Lamp on VIN: 1G2WP12K5W
this one is not fixed, released vehicle to customer, days later cust called and informed us that the eng lamp back on. sometimes its best to say " UNCLE " or " WHEN " OR " ENOUGH " Trouble codes: P0171.
1998 Pontiac Bonneville SE 3.8L MIL Lamp on VIN: 1G2HX52K0W
I found no ground to O2 sensor . When I supplied ground the o2 sensor started oscillating normally.Thank for all. Trouble codes: P0133.
2005 Pontiac Grand Prix 3.8L MIL Lamp on VIN: 2G2WP52205
Thanks for all the input. I have been using a local muffler shop for the past 10 years. They recently started selling a "jeavy metal" catalytic converter that we have used on several calif emissioned vehicles without a problem. I guess that had to catch up wit... Trouble codes: P0420.
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