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International Automotive Technicians Network
Prev Professional Automotive Repair Technical Discussions for August 17, 2006
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Open Help Requests for GM
Help Request Answers
1999 Buick Century Custom 3.1L Noise VIN: 2G4WS52M4X
Hi iATN techs, thanks in advanced for trying to figure out this problem. This car is my own vehicle. The car makes a noise both when applying load to the engine from a stop and right away releasing the gas pedal after the initial applying the heavy load. The f...
1993 Chevrolet K2500 Suburban 7.4L Low power VIN: 1GNGK26N5P
This has been to different techs and we are now working at diagnosing it. First of all the problem: The timing retards about 19 degrees when accelerated instead of advancing. This has had the computer replaced with a GM computer it has had a new Prom put in it...
1995 Chevrolet Lumina 3.1L Misfire VIN: 2G1WL52M1S
This car has a miss on No. 1 cylinder. If I take the injector conector from 1 and move it to number 2 cylinder then the miss also goes to number 2. I have ran a new wire from the ECM to the injector. I have rplaced the ECM. I have checked the injector connecto...
1996 Chevrolet Blazer 4.3L ac/heater mode switch VIN: 1GNDT13W3T
Having prob with my 1996 blazer, the typical upon accel the mode switches from the vent to the defrost. have replaced the vac check valve under the hood. can hear vac leak from the vac part of the mode switch on the dash. pulled switch and tested all vac lines...
2000 Chevrolet Astro 4.3L brakes VIN: 1GKDM19W3Y
customer came in with a pulling to the left, test drove vehicle toduplicate concern. it was evident 5 min. into test drive. brought vehicle into shop to check brakes. found the frt bearings had minimal play suggested repacking bearings. checked the operation o...
2001 Chevrolet Tracker LT 2.5L Idles high VIN: 2CNBE63481
This Tracker is in for a MIL on, idles high at times and intermittent no crank no start. We could not duplicate the no start. It only idles high with the AC off. The ECM is commanding the IAC from 25 in park to 64. Idles at about 1600 rpm in gear. Cleaned the ... Trouble codes: P0340
2003 Chevrolet Silverado 2500 HD 6.6L Tachometer VIN: 1GHK23123F
Good moring. I have a 2003 chevy 2500hd that the tach just quit working on. My scanner shows a tach signal so i think its the IPC but not sure. Shop key is not very clear where the tach signals generated from. Just looking for input before i replace somthing t...
2003 Chevrolet Express 3500 LS 6.0L a/c lines VIN: 1GAHG39U03
Good morning everyone. I have this van in the shop that needs the rear a/c lines changed (leaking due to corrosion). Alldata has no procedure for this, and the labor guide shows a little over an hour.The job looks like it could be a real bear,the rear ac line...
2004 Chevrolet Classic 2.2L ABS Module VIN: 1G1ND52F24
Pedal drops when firmly braking from 45-50 mph down -feels like abs is holding pressure and then releasing it- both rear inlet valves are activated when problem occurs- no pump motor running when it happens- does not appear to be a false activation- Braking pe...
1990 GMC V1500 Suburban 5.7L Surge, Cuts out, Stall VIN: 1GKEV16K1L
Thanks in advance. This problem that this suburban is having is probably common, but we are just unsure of how to test wheather it is the PCM or the ECM. The vehicle runs, and while in the shop the it will occasionally stall and the idle is at about 1000 RPM. ... Trouble codes: 22 (tps voltage low), 33 (map voltage low.)
1996 GMC C1500 Sierra SL 5.7L air in fluid VIN: 2GDEC19R8T
A power booster and master cylinder were replaced by a chain store. When the customer picked up the truck the brake pedal would go to the floor and the will not stop. The store then said the wheel cylinders were the problem. they replace them and the truck wil...
2000 GMC K3500 Sierra SLT 7.4L No Start, Cuts out, Stall, MIL Lamp on VIN: 1GTHK33J1Y
Hi everybody, have a head scratcher here. Truck came in with a code p0338 & intermittant stall/ misfire, changed crank sensor as per TSB in alldata, truck wouldn't start. Checked signal from new sens., found bad, replaced with new A/C delco sensor, same thing,... Trouble codes: P0338
2001 GMC Sierra 2500 SL 6.0L Misfire VIN: 1GTGK29U91
Hi guys got a bit of an odd one. This 2500 has a semi-random misfire at idle. Genisys scanner shows misfires on cylinders 1,2,5,6,7 an average of 6 times (sometimes 2,4 or none) for every 100 misfire data cycles. Noticed a couple plug wires had some nicks in...
2002 GMC Sierra 2500 HD 6.0L engine VIN: 1GTHK29U42
Hello fellow technicians and staff of IATN,I have a 2002 GMC K2500 with 73k miles and the customer is complaining of a engine noise and is convinced it is a lifter noise.I have looked at this problem and found a problem with lifter noises ,Yes.I initially did ...
2002 Pontiac Firebird Formula 5.7L MIL Lamp on VIN: 2G2FV22G12
I Have Never Saw This Code Before, I'm Not Sure Where to Go ?, My Alldata Won't Work Today Trouble codes: P0410
2004 Pontiac Grand Am SE1 3.4L starting VIN: 1G2NF52E14
Vehicle was towed to shop for no start condition. Customer stated that she had lost her key 4 months prior to problem and had been using flat metal key with no problems. On arrival engine would make about 1/2 turn when key moved to crank position then starter ...

Fixes & Summaries for GM
Fix/Summary Answers
1988 Cadillac DeVille 4.5L sets ac codes VIN: 1G6CD51559
It went away last Friday and we have not heard anything back so I will assume that the car is fixed and if I find out different I will add to the post. I had some very useful posts. One guy said to install a new temp sensor that sits just after the orifice tub...
1993 Cadillac DeVille 4.9L Hesitation, Surge, Cuts out, Stall, Misfire VIN: 1G6CD53B8P
thanks to everyone who answered my call for help. turns out we did have a bad ground at the starter but was because the stud that held the cable to the block was tight but broke. i moved the ground cable to the starter bolt & it seemed to run better but still ...
1994 Cadillac Eldorado 4.6L Poor Idle Quality
car is still not right. has cyl 6 and 7 not firing, got 6 to work. but not cyl 7. thinking maybe cam lobe warn down enough to cause no fire, but vacuum reads ok. compression ok. injector is popping, can spray carb cleaner into it, and it wont fire number 7. cu... Trouble codes: P0135.
1986 Chevrolet Corvette 5.7L Excessive Emissions, Poor Idle Quality VIN: 1G1YY0785G
thank everyone that sent ideas on this problem: iac relearn, distributor problem, number of place i might find a good throttle body (didn't have this one), other things that i had tried. turned out there was a short in the wire harness to the iac valve, repair...
1997 Chevrolet Cavalier Z24 2.4L MIL Lamp on VIN: 1G1JF12T1V
We'll not too many responnses. We have not replaced anything on this vehicle. Since the Diagnostic was done the light has not re appeared. So what the heck is the fix. Tracing back out steps we have found that we spent alot of time working the solenoids and ve... Trouble codes: P0442 (Evap control system small leak detected).
2001 Chevrolet Silverado 2500 HD 6.6L No Start VIN: 1GCHK23171
Thanks for the 4 replies.Most said to look for air getting into the system.Upon further inspection we found that the main fuel line coming from the tank had been crushed up against the frame sometimes earlier in this trucks life when someone else must have had... Trouble codes: P0094, P0380.
2002 Chevrolet Suburban 1500 LS 5.3L lifters VIN: 1GNF16Z72J
found the oil pump pick up screen plugged and the pan full of sludge, thanks for all your help, cleaned pan and replaced screen no noise , and thats great,thanks again.
2003 Chevrolet Silverado 2500 HD 6.0L oil presure VIN: 1GBHK24U23
Thanks to all who took the time to reply to my help request.It would appear after reading all of the responses that my gutt fealing was right.I was thinking that a motor with 110,000 miles in todays standereds should not be shelling out the lower end,i guess t...
1995 GMC Jimmy SL 4.3L Air Bag VIN: 1GKDT13W0S
The replys were spilt about 50/50. Half said to replace the clock spring due to the code 26 and the other 1/2 said to replace the DERM. I checked with a mechanic at our local GMC dealer and he suggested checking the DERM connector for corrosion. He also said t...
1996 GMC Safari SLE 4.3L Mechanical VIN: 1GKEL19WXT
Hey thanks to all who answered. You won't believe it but we have had two new hoses that are plugged. The second one we took right out of the box and couldn't blow air through it. I have been in this business for over 30 years and I guess I still have things to...
1998 GMC Jimmy Envoy 4.3L blower motor VIN: 1GKDT13W6W
Thanks to all who replied. The ignition switch was the culprit. My gut told me that was probably going to be it but I wanted to be sure. Again, a big thank you and have a great weekend!
1992 Pontiac Bonneville SE 3.8L Ignition key switch VIN: 1G2HZ52L0N
Thanks to all who replied. Most had the same type of fix in mind, but I had no luck from two dealerships trying to get the original resistance values from the VIN. I ended up using the resistance chart and just substituting different resistor combinations unti...
2002 Pontiac Grand Am SE1 3.4L No Start VIN: 1G2NF52F92
thanks for all the replies.the passlock sensor done the trick
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