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Prev Professional Automotive Repair Technical Discussions for March 23, 2006
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Open Help Requests for GM
Help Request Answers
2000 Buick Regal GS 3.8L Hesitation, Cuts out, Misfire VIN: 2G4WF5517Y
I have this regal with a misfire taking off from stops can duplicate in shop by snapping the throttle with no load and it happens just off idle has just 3-4 quick missfires then runs good at all speeds most noticable from a dead stop can not duplicate when cru...
1978 Chevrolet Camaro 5.7L Cylinder heads
Student has bought a set of aftermarket aluminum cylinder heads for his engine. Renegade brand, angle plug small block chevy, purchased from Motorville, a performance parts supplier. The heads are manufactured overseas and they have no web site, and I called M...
1993 Chevrolet K2500 Cheyenne 7.4L Misfire, BACKFIRES VIN: 1GBGK29N6P
Need some Big Block techs to help out here. Got this from another shop-starts right up when cold and begins bucking, backfiring, farting and generally runs like real crap. You can acellerate this throttle body unit radpidly and it winds right up, but when you ...
1995 Chevrolet K2500 Cheyenne 6.5L Surge, Misfire VIN: 1GCFK29SW7
I think this truck has two problems. First under light acceleration, usually around 20% it will loose power blow some gray smoke and run rough. It feels more like a surge than a misfire. My scan data doesn't show anything out of line except it seems to always ...
1997 Chevrolet Astro 4.3L MIL Lamp on VIN: 1GCDM19W2V
this vehicle keeps seting throttle position code. Takes several hours of running before code.than after several hours the p0121 code will return Trouble codes: P0121
1999 Chevrolet Express 3500 5.7L Poor Idle Quality, Surge, hunts for idle VIN: 1GCHG35RXX
this van has a very severe hunt for idle in reverse. It acts up when backing up to hook on a trailer at idle in reverse. It hunts up & down 400 - 1200 rpm. The iac counts go up & down. I have a new maf on it, set the sync to 0 deg, trans line pressure is swing...
2000 Chevrolet K2500 7.4L No Start VIN: 1GCGK23J45
This is my personal truck.I can let it set for days and it starts fine.Let truck set for 30 min to about four hours and it has aextened crank.Runs a little rough when started and has a small amount of black smoke.On one occurance when started hot cranked hard ...
2001 Chevrolet S10 4.3L Poor Idle Quality, Misfire VIN: 1GTDT19W21
Hi just got back from mexico should of stayed there. My co worker left me with a jack pot.He replaced plugs wire cap rotor trying to get rid of a missfire in 1 3 5 cylinders.He spend sometime trying to diag but didnt get anywhere so I got it.Scan shows b1 s1 g... Trouble codes: P0300
2001 Chevrolet Impala 3.8L idle creeps up VIN: 2G1WF52K31
I'm sure there is something going on with this car that takes out the ECM. I find it hard to believe that I could have a new ecm that fails the same as the old one. Unfortunately I just don't have any idea where to look. Sensor values all looked OK with new ec...
2004 Chevrolet Trailblazer LS 4.2L torc convertor VIN: 1GNDT13S34
Need some help from GM trans tech guys. This trailblazer came in late today and all I had time to do was test drive it. Driving about 50 I notice that the lock up torc convertor seemed to be locking and unlocking and at time it felt like the vehicle was chatte...
2006 Chevrolet Silverado 1500 LS 4.3L ecm VIN: 3GCEC14X86
Good morning, My customer ordered a Silverado WITH cruise, but it came WITHOUT. It looks to me like the ECM also runs the crusie control on this. Can it be retrofitted... At a switch and reprogram? How can cruise be added to this truck?
1991 Geo Metro 1.0L No Start VIN: 2C1MR2469M
I live in wa. and am trying to help my dad in ca. His geo will start and then die. He thought it was a fuel pump so he replaced it and it ran ok for a week. Then the same symtoms started again. Starts and runs for a few sec. and then dies again. always starts ...
1993 GMC C3500 Sierra SLE 5.7L brake pedal feel VIN: 1GTHC39K3P
93 GMC dually w/hydroboost. Brakes will put you into windshield with normal brake pressure. Replaced presure hose between p/s pump and hydroboost unit w/ gm hose. Mitchell pretty slim on info on system. Trobleshooting flow charts were inconclusive. Pedal feels...
1995 GMC K2500 Sierra SL 5.7L No Start VIN: 2GCEK29RXT
Hi everybody : I worked in a used car dealership,this vehicle has a 6.5 L disel engine orignally,somebody installed a 2000, 5.7 L with a electronic-control transmission in it. We had this truck about 6 weeks ago running in and out in the lot without any probl...
1993 Oldsmobile Cutlass Supreme S 3.1L loss of power VIN: 1G3WH54T5P
I've got a '93 Cutlass Supreme with a 3.1L engine. It came into the shop with complaint of no power. On road test it felt exactly like a plugged converter. Removed convertor and found inside broken loose. Replaced converter with no change in condition. Thought...
2002 Oldsmobile Bravada 4.2L Poor Idle Quality, Misfire, Poor Fuel Economy, MIL Lamp on VIN: 1GHDT13S42
We still have a rough idle and code p0171 sets right after codes are cleared and run for 1 minute. The CEL comes on after the engine is shut off and restarted. Trouble codes: P0171, P0501
2001 Pontiac Grand Am GT 3.4L suspension VIN: 1G2NV12E01
i am working on 01 pontiac grand am gt it has clunk noise in left front area i replaced right front wheel bearing it was loose i have tighten everything underneath car lower control arms , cradle engine mounts transmission mounts took sway links off, grease st...

Fixes & Summaries for GM
Fix/Summary Answers
1994 Buick Regal Custom 3.8L brakes VIN: 2G4WB15L4R
of the 10 replies we recieved on this request, 9 were geared toward a problem with vacuum, the vacuum booster or a base braking concern of some sort. Prior to submitting the request for help, we had already ruled these items out as a possibility with extensive...
1995 Buick LeSabre Custom 3.8L No Start, Stall VIN: 1G4HP52L85
thanks for all the input. the injector pulse stops after 30 seconds crk sensor checks out on the scope replaced the key with new and the security system a ok the last thing was the ecm and the customer declined the repair and took the car
1998 Buick Regal 25th Anniversary Edition 3.8L Body VIN: 2G4WF5211W
Thanks to all of you who responded to our cry for help. We have managed to repair this vehicle by replacing the harmonic balancer. When we took it off & looked at it we could not see anything wrong with it. We installed a new one anyways and noise was gone.
1995 Chevrolet Astro CL 4.3L No Start, Cuts out VIN: 1GNDM19W2S
thanks for all help. the connector on the injector needed to be cleaned and tightened problem solved thanks again
1995 Chevrolet K1500 Cheyenne 5.7L oil pressure VIN: 1GCEK19KXS
We talked with the customer about the options of dropping the oil pan, and he did not want to do the work on that old of a truck. Especially since he just paid for the intake and lifter to be replaced. He said that now at idle the oil pressure is reading 10psi...
1996 Chevrolet K1500 Cheyenne 5.7L No Start VIN: 2GCEK19M9T
Of the 27 responses i got the vast majority recommended a fuel pump.That was right on the money.The strange thing is the pressure is still at a steady 54 psi while running.This was a GM pump ,the cranking pressure no longer drops and all is well.I also motovac...
1996 Chevrolet S10 LS 2.2L Misfire VIN: 1GCCS1942T
Thanks to all who replied. I replaced the other coil pack (which I should have done in the first place) and the ignition control module. Customer has driven the truck for a week now and it seems like the problem is fixed. Thanks again!!
1996 Chevrolet Lumina 3.1L ABSmodule VIN: 2G1WL52M7T
hey guys sorry for taking so long to close this one up.It turned out the ground wire was corroded cleaned it up and abs light is off now thanks again guys.
1997 Chevrolet C3500 Cheyenne 5.7L Hesitation, MIL Lamp on VIN: 1GCGC34RXV
Hello all and thanks to those that replied. After replacing the ckp sensor and repairing a loose ground at the right cylinder head the truck appears fixed as has left my shop 2 weeks ago and cust says running great. Paul Trouble codes: P0340.
1997 Chevrolet Monte Carlo LS 3.1L MIL Lamp on VIN: 2G1WW12M4V
Thanks to all who replied. I took the t/b off and there was a bunch of carbon there. cleaned it out and went thru the drive cycle and no codes at this time...I guess well find out in about a month if it fixed it!! Again thanks to everyones responses. Trouble codes: P0401.
1999 Chevrolet Tahoe LS 5.7L p/s pump VIN: 1GNEK13R7X
it is very frustrating when you spend the time contacting so many great techs only for the customer to decide to wait to fix. i recommended the steering gear box and stated that the pump & hoses may need replacement as well. i will update the post as soon as w...
2002 Chevrolet Trailblazer LS 4.2L No Start, Cuts out, Stall VIN: 1GNDT13S72
hi, sorry for taking so long to reply. the fix was the ignition switch. once it was replaced everything was great.
1995 GMC C1500 Sierra SL 5.0L Unknown VIN: 1GTEC14H5S
Sorry so long but the customer has notreturner for repairs. The general consensus was that the ignition switch and or wiring has a problem. If he returns I will let you know. Thanks everyone.
1997 GMC Jimmy SL 4.3L tcc slipage VIN: 1GKPT13W5V
thanks for tips i decided that i had a glitch after finding out that service light wouldnt come on until i had made a complete stop after clearing code,i said this is very odd ,nothing going on at idle with tcc, i nstalled new vcm fixed vechile thanks for all ...
1998 GMC Safari SLE 4.3L Misfire VIN: 1GKDM19W0W
Hi guys Thank you to all that replied .I recieved 15 reples to my problem and about 80% all pointed me in the right direction and and were right on .The problem ended up being a worn distributor gear .With the scanner on it reading cam position which should be...
1999 GMC Safari SL 4.3L Oil leak VIN: 1GTDM19W8Y
My original thoughts were with the oil pump but I was trying to make sure that there was not something I might have missed before I spent more of this customers money. There was a severe buildup of carbon within the engine. Visual chunks were in the oil pan an...
2003 GMC Yukon XL 1500 SLE 5.3L A/C Vent Mode Door VIN: 3GKEC16Z43
Thanks to all who replied. I tried David [...]'s reply but this did not solve the problem. The mode door would switch to all the vents during the calibration period but then would remain on the defrost. I then figured I need a Tech2 to solve problem, so I ...
1992 Oldsmobile Achieva S 2.3L Excessive Emissions, Poor Fuel Economy VIN: 1G3NL5434N
I got 9 replies with the suggestions being all over the place. I won't add them all here as they are readily available in the archives. I haven't been able to get the car back in, but it seems that there are no pattern failures of this type evident for this ve...
1999 Oldsmobile Bravada 4.3L No Start VIN: 1GHDT13W6X
Well - we exhausted all our diagnostics in checkling for leaks and poor electrical connections - we have replaced the entire injection / fuel delivery system with OE parts and made sure the connections were good and tight - we have seen the vehicle back a few ...
2001 Oldsmobile Intrigue GX 3.5L Misfire, MIL Lamp on VIN: 1G3WH52H21
After switching coils and a bunch of other stuff. We motovaced it and it hasn't been back yet. Thanks for the help. Glenn Trouble codes: P0300.
2001 Pontiac Montana 3.4L No Start VIN: 1GMDX03E21
Hey everyone, Thanks for trying to help. I tried communicating with the bodt computer and it wouldn't comm. so I started tracing the serial 2 data line.Everything checked out o.k. I already had the dash half apart so I went ahead and pulled the inst. panel out... Trouble codes: P1626.
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