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International Automotive Technicians Network
Prev Professional Automotive Repair Technical Discussions for February 10, 2010
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Open Help Requests for GM
Help Request Answers
1994 Buick Roadmaster Estate Wagon 5.7L hard start VIN: 1G4BR82PXR
did a fuel pump on this wagon about a month ago. customer complains of hard start when cold. put a fuel pressure gauge up to it and found that after the car has been sitting, the fuel is bleeding back into the fuel tank causing it to lose fuel pressure. so far...
2002 Buick Rendezvous CXL 3.4L No Start VIN: 3G5DBO3E62
Thanks to all. Car came in on the hook and would not start. I checked the fuel pressure and it was within specs (not on the low side). I checked the spark and had a strong blue arc. Then I got called on another tow and when I got back to shop the car started. ...
2001 Chevrolet Express 3500 5.7L Poor Idle Quality, Misfire, MIL Lamp on VIN: 1GBHG31R61
Customer states the engine runs rough, lacks power, and check engine light is on. Scan for trouble codes. P0335, P1637, P1638. I scoped the CKP signal wire at the PCM. Had a square wave signal. Checked power and ground at CKP sensor. Checked out ok. Perform vo... Trouble codes: P0335 (CKP Sensor A Circuit Problem), P1637 (Generator L-Terminal Circuit), P1638 (Generator F-Terminal Circuit)
2004 Chevrolet Express 3500 6.0L Poor Idle Quality, Misfire, MIL Lamp on VIN: 1CGHG39U44
#7 cylinder skipping at idle. Goes away at 2% throttle. #2 also skips at times but I beleive that's a sympathy skip. Trouble codes: P0300
2004 Chevrolet Silverado 1500 5.3L MIL Lamp on VIN: 2GCEC19TX2
Test drove it about 30 miles no light. next day light on and code p0420 is on. I drove it for about 20 minutes and rechecked and found p0430 in code. this truck has a slight stumble at idle so I think it is the maf sensor. Back pressure test normal on cats did... Trouble codes: P0171, P0174, P0420, P0430
2005 Chevrolet Trailblazer LT 4.2L Starting VIN: 1GNDT13S25
The trailblazer came in with the complaint of intermittent no crank, but never stranded customer. No codes in any module. A couple times i wasn't getting a ground to the starter relay, backprobed pcm from ignition and backprobed pcm to relay but now it won't a...
1993 GMC G3500 Vandura 5.7L Electronic VIN: 1GDKH32K2P
Hello all would like to pick your brains, mine isn't working. We have this big ugly cube van we put a used engine and a rebuilt trani in it. Worked great for 2 months then started to flaire up in 4th gear while hitting bumps,thats right bumps, if the road is s...
1998 GMC Savana 3500 5.7L Stall VIN: 1GJHG39R1W
Thanks to all. I get this van because somebody else cant fix it. This van starts all the time but stall at any time. The stalling is not regular, it will do it any time (hot or cold). You can be parked or driving. Will start right up after it stalls every time...
2001 GMC Sierra C3 6.0L transmission VIN: 2GTEK69U51
hey guys...owner brought this c3 to my shop on a rope. he says he was driving along back road, slowed for an intersection, and when he tried to accellerate there was no go. actede like tranfer case was in neutral. says trans has been to atrans shop twice recen...
2005 GMC Savana 3500 6.0L Poor Idle Quality, Stall, MIL Lamp on VIN: 1GDHG31UX5
real headache here. about 6 months ago comes in with stalling problem - always restarts. this is a business delivery van, very heavy use like 5 to 7 thousand miles per month. we diagnose a bad iac, can't buy it seperatly, replace throttle body. comes with iac ...
1997 Oldsmobile Cutlass Supreme SL 3.1L Timing chain cover VIN: 1G3WH12MOV
The timing chain cover is leaking coolant at the rear bank of the block. Service info says to drop subframe to remove oil pan, to remove t-chain cover. Is there any way to leave oil pan in place and slide the t-chain cover off of the oil pan gasket? The front ...
2003 Pontiac Grand Prix SE 3.1L dome lights VIN: 1G2WK52JX3
hi all i have problem with this 2003 pontiac grand prix.the dome lights staying on.i replaced bcm and was good for a couple days. then thay started staying on again.will time out about 15 min.tested power and grounds at bcm all check ok.any one run in to this ...

Fixes & Summaries for GM
Fix/Summary Answers
2003 Buick LeSabre Limited 3.8L Surge, Stall VIN: 1G4HR54K23
was never able to reproduce the symptom all my readings were after all repairs and cleaning also reset the min idle. Last step we did was install a carbon trap in the EGR. has not been back. Thanks for your help
2004 Buick Century Limited 3.1L MIL Lamp on VIN: 1G4HR54K14
Replaced tank pressure sensor, been three weeks so far so good. Thanks David Trouble codes: P0442.
1988 Chevrolet Blazer Scottsdale 5.7L Poor Idle Quality, Hesitation, Surge, Cuts out, Stall, MIL Lamp on VIN: 1GNEV18K3J
well it turns out it needed a fuel pump. When the customer came in he claimed the fuel pressure was good and he installed a new fuel filter. I guess he doesn't understand 5 psi is not enough.
1995 Chevrolet S10 4.3L shift VIN: 1G2BTE4ZTC
I have relied on iATN for many years for the great techs with information and resources that are out there to help. Many of you responded with some great advice. Unfortunately I did not post a 95 S-10 shift concern, either my user information was compromised o...
1998 Chevrolet C1500 WT 4.3L Cuts out, Misfire, MIL Lamp on VIN: 1GCEC14W2W
Sorry for taking so long to close, customer has not brought back in yet, i feel that i have eliminated everything except grounds and sticky valves so untill i get it back can't give a fix. sorry. and thanks to those who took some time to read the all of the re... Trouble codes: P0300.
2000 Chevrolet Venture LS 3.4L MIL Lamp on VIN: 1GNDX03E4Y
thanks for all sugestions and comments all you guys are great,like i said before back to basics installed a factory part and no more compliants,and yes i know better to use aftermarket parts.first time for everything thanks scot
2003 Chevrolet Silverado 1500 5.3L fuel gauge
thank you all who responded. it ended up being a faulty "new connector harness" i had not changed the harness when i tried the second new assembly and it turned out the ground short in the harness connector which came with the new pump did the trick. cleared t...
2007 Chevrolet Avalanche LT 5.3L MIL Lamp on VIN: 3GNEK12397
I'm going to call this one fixed as I just called the owner to follow up and found that in amount of time that has elapsed from the last time I looked at this vehicle to the point at which the vehicle was traded in there had been no recurrence of any MIL. The... Trouble codes: P0481 (Cooling Fan Relay 2 Control Circuit).
2008 GMC Yukon Hybrid 6.0L No Start VIN: 1GKFK13518
Sorry for the late close vehicle is fixed seems snap on still has some glitches in there 9.4 software. Even though the impact reset test was in the new software it would not complete reset kept getting unspecified error test not complete,borrowed a tech 2 with...
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