GM Automotive Technicians Technical Discussion and Fixes for Jan 14, 2004

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Open Help Requests for GM

	Help Request	Answers
	1994 Buick Roadmaster 5.7L starter VIN: 1G4BR82P5R I hope someone can shed some light as I think this is going to haunt me. Vehicle came in with an intermittent no crank/hard crank condition. We tested and replaced the starter and tested fine. Customer came to pick up vehicle and came back in stating the vehic...	View
	1990 Chevrolet C1500 Cheyenne 5.7L a/c control head VIN: 1GCDC14K3L vehicle came in with control head flashing and temp works, mode doors work, tried 2 control heads checked all my wiring 1 by 1 of course checked the freon level, there is no tape on any of the wiring harness underneath the dash. i am stuck i have worked on thi...	View
	1995 Chevrolet Monte Carlo LS 3.1L Misfire, Vibration VIN: 2G1WW12M35 I thought I have run into all situations with these 3.1 motors but this one is boggling me. It shakes @45-50 mph in overdrive. Fells like a secondary misfire. I have replaced and tested all ignition components and found no problems. I have ohmed the injectors ...	View
	1995 Chevrolet Caprice Classic 5.7L Cuts out VIN: 1D1G1BL52P Hi group, this Caprice came in with a complaint of loosing power under hard acceleration. After trying a few times we finally did get it to act up. It seems it acts up(for us)when it's warm and then sets for an hour or so(hot-soak?). When you first drive it th...	View
	1996 Chevrolet K2500 5.7L Poor Idle Quality, Misfire, MIL Lamp on VIN: 1GNEC13RJ7 this is my first request for help. truck hasbeen converted to r/h drive.idle irratic hunts up and down on idle . with air con on idle stabilizes, almost to acceptable levals, no info available on this vehicle in australia . borrowed snap on cartridge from impo... Trouble codes: P0300	View
	1996 Chevrolet Astro 4.3L Misfire, MIL Lamp on VIN: 1GBDM19W1T Hi Y'all, This thing has us stumped. On the interstate @ 70 MPH or so every now and then it will stumble (missfire). Using the Snappy MT2500 and watching the mis fire count it will run about 255 per cycle but never has set a missfire code. It does set the P01... Trouble codes: P0106 (Map sensor system problem)	View
	1999 Chevrolet K2500 5.7L Hesitation, Stall, MIL Lamp on VIN: 12K7342U4K I have got this chevrolet K2500 that is driving me nuts I have done everything I can think of.The truck acts as if it has a realy bad vaccuum leak, I have been all over it with propane and nothing shows up. The EGR valve is fine, I have removed the fuel inject...	View
	1999 Chevrolet Tahoe LS 5.7L tcc VIN: 1GNEK13R8X This truck has minor surge while TCC is engaged. When driving at steady speed or light accelleration the TCC duty cycle will start to drop off from about 40% to 45% down to around 25% and will disengage slightly and slip speed will come up to around 75 to 100 ...	View
	2001 Chevrolet Silverado 2500 6.0L transfer case VIN: 1GCHK29U51 Hi, i have this problem child that will not go into 4wd. I push the selector swith and it tries to go into 4h or 4lo and then goes back to 2h. if i put into nutral it will try to go into 4lo but will click and stay in 4h untill you turn the ignition off. I am ...	View
	2001 Chevrolet Silverado 2500 HD LS 6.0L engine VIN: 1GCHK23U11 I looked it this truck for a friend. The engine died why running out side and wouldn't turn over. Removed serp. belt and found crankshaft wouldn't move. Drain engine oil found lots of metal particles. He has had this into the dealer 3 times the first being a...	View
	2003 Chevrolet impala 3.8L battery VIN: 2G1WH52K13 Hello all This customers complaint is the car can be left over night and the battery will be dead in the morning. This is an intermittent problem, it might happen two days in a row and not happen agian for a week. The customer has had it to the dealer 5 times...	View
	1995 Geo Tracker 1.6L MIL Lamp on VIN: 2CNBJ18655 Vehicle came in one month ago with a check engine light, retrieved code 15, replaced coolant temperature sensor. Vehicle came back in showing code 51, with some test we replaced exhaust temperature sensor. Vehicle came back in we replace coolant temperature se... Trouble codes: 15 (engine coolant temperature sensor), 51 (exhaust temperature sensor)	View
	1997 GMC C3500 Sierra SL 7.4L lock -up convertor VIN: 1GTHC39J9V No convertor lockup,scan data duty cycle stays at 0%. If you command lock up with TECH2 duty cycles from 0 to 97% and engine rpm drops. All scan data, including TPS appears normal and there are no codes. Note: Odometer only increments .9 for every milemarker. ...	View
	1999 GMC C3500 Sierra SL 7.4L exhaust valve VIN: 1GDKC34JIY We have this fleet truck with a noise (that sounds identical to a noisy belt) in the #5 exhaust valve. It won't make the noise with the rocker arm removed. We removed the valve spring and inspected it for damage. The only thing we found was some noise coming f...	View
	2000 GMC Sierra 2500 SL 6.0L hard start hot VIN: 1GTGK29U9Y Hi folks,got a 6.0l here that will not hold fuel pressure after shutdown It bleeds off to 0 within a half hour.When you restart it after this time (unless it sits all night) it cranks long,smells rich and puffs black smoke.I put a clear vacuum line to the regu...	View
	1986 Oldsmobile Delta 88 Royale Brougham 3.0L Excessive Emissions, Poor Idle Quality VIN: 1G3HY69LZG Snap On scanner in 'diagnostic mode' vehicle runs fine. everything normal as far as values. In 'road test'(c&d) mode, vehicle idles rough, sulfer smell from exhaust, knock sensor always shows 'yes' even when disconnected. Retards timing to 0 degrees. In diagno...	View
	1996 Oldsmobile Aurora 4.0L all windows innop VIN: 1G3GR62C3T Hi there, car in for oil service, client also mentioned heated rear window innop. upon checking the fuses under rear seat AND NOTHING ELSE, the power windows stopped working, the door were open for quite a duration. window circuit breaker good, remove master s...	View
	2001 Oldsmobile Silhouette GL 3.4L Unknown VIN: 1GHDX03E1V Hi techs, this 01 silhoutte van has no heat coming from the heater. The coolant temperature is 180 degrees,the rear heat works. With the temp selector on cool, all modes work ie vent-defrost-floor-bi-level. When the temp selector is set on heat the air flow be...	View
	2001 Other GM motorhome 8.1L No Start VIN: 5B4LP57G71 motorhome was towed in no start, found low ref wire to coils shorted to driver wire to #3 injector. ck all power and grounds at pcm, ck for square wave at pcm (crank and cam sensors}with vantage good signal.replaced pcm but still have no injector pulse or spar...	View
	1994 Pontiac Firebird Formula 5.7L Hesitation, Cuts out, Misfire, detonation VIN: 2G2FV22P3R Hi, need help with this Pontiac please. Heavy engine miss and detonation under load. Initial inspection uncovered small tear in intake duct to throttle body, wish it had been that simple. Replaced the $200.00 duct and had no change at all. Also test MAF and TP...	View
	1995 Pontiac Grand Prix SE 3.1L Excessive Emissions, Poor Idle Quality, Misfire, Poor Fuel Economy VIN: IG2WJ52M1S this car has a dead miss on # 3-6 cylinders...no spark we replaced module...coil pack and 5 x sensor still no spark	View
	1999 Pontiac Grand Prix GTP 3.8L Misfire, MIL Lamp on VIN: 1G2WR1216X Vehicle came in for engine maintenance/spark plugs. Technician found spark plug wires also bad, spark plugs worn out. Replaced spark plugs & plug wires. Technician also cleaned throttle body with air intake cleaner. Car was road tested, technician returned wit... Trouble codes: P0300	View
	2000 Pontiac Grand Am SE 2.4L No Start VIN: 1G2NE52T6Y Hi Guys, I have this Grand am that came in with water in the fuel from a local fueling station. I removed the tank and cleaned it out and replaced the fuel filter and flushed the lines with my motorvac. It has fuel pressure & fire but will not start. I can spr...	View
	1998 Saturn SL2 1.9L Electronic VIN: 1G8ZK5276W Hi Saturn Tech's, We specialize in Saturns so I'm usually helping not asking. We have a 98 Sl2 that most of the time trans is in 4th limp mode. Codes are as follows: p0732,p0747,p0759,p0764,p0768,p0782. Checked all actuator resistances, all ok. new connector p...	View

Fixes & Summaries for GM

	Fix/Summary	Answers
	1994 Buick Roadmaster Limited 5.7L body seals VIN: 1G4BT52P6R I recieved four replies to this problem. Most of the info pertained to the cowl area and heater/AC box,with one on door seals. As stated this leak was on the driver's side. All replies though make you stop and think about the problem at hand. Thanks to all tha...	4
	1995 Chevrolet K2500 Cheyenne 5.7L Surge, Misfire VIN: 1GCGK29K9S Thanks to all who helped,found problem to be pick up coil	21
	1995 Chevrolet S10 4.3L Excessive Emissions Thanks for all of the help, but I had to give up on this one. I tried the following with no results: 1. adjusted tps voltage to 1 v. 2. relearn by disconnecting battery 3. retard timing 2 deg.(maximum allowed by ca law, droppes nox to 1500 ppm) 4. checked tota...	10
	1997 Chevrolet S10 2.2L Power steering pump VIN: 1GCCS1445V It's finally fixed!Thank you all that took the time to help me out. I tried almost all your suggestions.I flushed the system and bled the system and it was the same thing.So I thought maybe the hose so I started to clamp it off and listen for any changes.Eve...	12
	1998 Chevrolet Blazer 4.3L Transfercase VIN: 1GNDT13W3W I only recieved 3 replies in two weeks, one of which has never driven a 4/wd but did have an understanding that 4/lo was for slow rugged driving and I do appreciate the reply. One reply stated that the wiring harness could be the problem. We have checked all t...	4
	1998 Chevrolet Malibu 2.4L Poor Idle Quality, Surge, Cuts out, Stall, Misfire, MIL Lamp on VIN: 1G1ND52T4W Well guys I finally wooped it with some much needed help. As I had forgotten to post on my original message, I had already pulled the injectors and soaked them in Techron. I also measured continuity between the posts on the coil tower and found no continuity b... Trouble codes: P0300.	11
	2000 Chevrolet Silverado 1500 5.3L MIL Lamp on VIN: 1GCEC19T7X i replaced the cat. on the #1 bank and my 1/2 02 reading was steady 750 mv and took care of my p0420 Trouble codes: P0420.	16
	2001 Chevrolet Silverado 1500 5.3L Misfire, MIL Lamp on VIN: 1GCEK19T01 vehicle is fixed. replaced cat convertors. one side was plugged. missed it on back pressure test which showed no back pressure problem. vehicle was fixed before I recieved Jasons email. hit it on the head with one cat being plugged and the other one ok. most o... Trouble codes: P0300.	22
	2002 Chevrolet Impala 3.4L cruise motor VIN: 2G1WF52E72 Many thoughts on cruise diagnoses. Read the replies. I may have not beat enough info out of the customer. It came out in conversation that it does it some times in a parking lot without the cruise on. I cleaned the throttle body yesterday, today the temp h...	4
	2003 Chevrolet cavalier 2.2L Stall, MIL Lamp on VIN: 1G1JF52F53 My apologies for not gettting this case closed sooner but between several people being out sick and a couple other techs that had some severe family problems I was so short handed I didnt get back to it for a while. Finally found that the Airbag module under t... Trouble codes: U1002 (u1016-), U1016, U1064, U1088.	8
	1990 GMC K2500 Sierra SLE 5.7L Poor Idle Quality, Hesitation, Stall VIN: 1GTGK24K1L Hello everyone. I am a little late in replying my fix. I have the vehicle up to 75% better, and returned it to the customer and recommended he return for more diagnosis. He is currently busy plowing driveways and cannot return. However, iatn techs submitted ex...	12
	1999 GMC Savana 2500 5.0L speedometer VIN: 1GTFG29M6X Thanks for the replies. The problem is fixed thanks to you. Four replies said to check the PCM for water corrosion inside and a couple said that the seams of the PCM will split due to the corrosion. There wasn't a split seam but there had definitely been water...	7
	1990 Oldsmobile Cutlass Supreme 3.1L electronic heater control VIN: 1G3WS51TXL Thanks for the help!I took the electronic climat control appart and i found a cracked resistor so i souldered right across it and by luck voila! Everything works fine thanks again its cold out here in Sudbury Ontario -40c burrrrr!	3
	1998 Saturn SL 1.9L MIL Lamp on VIN: 1G8ZF528XW some techs report that there is a reflash for this problem and some techs say no. customer has not come back and waiting. going to close post, if customer comes back I will update. I think myself that the computer is to sensitive and needs an update...we will ... Trouble codes: P1404.	8

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