92STS Posted July 3, 2006 Report Share Posted July 3, 2006 The car: '92 STS 4.9 The problem:--------------------------------------------------------------- no instrument cluster funtions (tach,speedo, climate control, LEDs),windows don't work and the car seems down on power. I can't even bring up codes. SES and anti lock warning lights do work. "Key in ignition" warning is a quick, faint tone. Radio works. All lights work. Idle controller runs longer than usual when the key is shut off. The story:------------------------------------------------------------------ The car was idling high at about 1500 rpm for a day or two before this happened. Everything else was working fine. On my way home I got a SES light for the last 15 minutes of my trip. I watched the coolant temp, it maintained around 218 degrees, volts were around 12. Parked the car for about two hours and the the above symptons appeared. Actions I have taken so far:------------------------------------------- 1: spent 2 hours on Caddyinfo.com (standard opperating procedure) 2: Cleaned battery terminals 3: Checked every fuse in the car (including the 50 and 60 amp) 4: Disconnected positive battery cable 5: Disconected negative battery cable 6: Checked all vacuum line for cracks 7: Unplugged idle controller 8: Unplugged throttle position sensor 9: Scratched my head 10: Scratched another part of my anotomy. Actions I am about to take:---------------------------------------- 1: Have a couple of beers and worry about it in the morning. 2: Leave it in the good hands of the brain trust at Caddyinfo.com Tommorow I might take a look at the plug and ground on PCM. Thanks in advance for your guidance. Cheers, T. Link to comment Share on other sites More sharing options...
PAUL T Posted July 3, 2006 Report Share Posted July 3, 2006 You are moving in the right direction with the PCM. I would bet on a bad battery or a ground. How old is the battery? Check the grounds to the frame. Link to comment Share on other sites More sharing options...
adallak Posted July 3, 2006 Report Share Posted July 3, 2006 218 is pretty high for 4.9 engine if it is not a city driving. I suspect your serpentine belt is slipping (bad tensioner?), and both water pump and alternator do not work properly. As Pault advised, check grounds one more time, or just put a jumper form battery negative to engine block. Have you recently replaced the alternator? The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
92STS Posted July 3, 2006 Author Report Share Posted July 3, 2006 Paul, The battery is about 3 months old. I did a load test on it after I saw your post. It was at 12 volts just sitting there and about 11 volts under load test. I had cleaned the terminals yesterday because the positive was a little dirty. Adallak, The car usually runs in the 213-218 range on the highway. I don't often check it around town though. Maybe it is time for a termostat. The alternator has not been replaced but the water pump was relaced a couple months ago along with a new belt. I am not sure how tight the belt should be. I can move it about 3/8 of an inch on the front span with one finger and medium pressure. I will check the grounds at lunch time. I am still driving it locally as it is my only means of transportation. Thanks guys. Link to comment Share on other sites More sharing options...
Dan Posted July 3, 2006 Report Share Posted July 3, 2006 Your voltage seems a little low. Hook jumper cables to another car and seeing if things start working. While the car is running you should be getting 13-14v. Your car is very sensitive to low voltage. It won't even start if the voltage is even a little bit below 12v Link to comment Share on other sites More sharing options...
adallak Posted July 3, 2006 Report Share Posted July 3, 2006 Paul, The battery is about 3 months old. I did a load test on it after I saw your post. It was at 12 volts just sitting there and about 11 volts under load test. I had cleaned the terminals yesterday because the positive was a little dirty. Adallak, The car usually runs in the 213-218 range on the highway. I don't often check it around town though. Maybe it is time for a termostat. The alternator has not been replaced but the water pump was relaced a couple months ago along with a new belt. I am not sure how tight the belt should be. I can move it about 3/8 of an inch on the front span with one finger and medium pressure. I will check the grounds at lunch time. I am still driving it locally as it is my only means of transportation. Thanks guys. The tensioner has an indicator showing the acceptable range. When car is cold check the level of the coolant inside of the radiator. Do not rely on surge tank since it may be full but the radiator half empty because of a plugged hose to the surge tank. My alternator puts some 14.5 V. The battery is six-years-old, and usually holds some 11.4V - 11.7V, but the car starts okay even in the winter. The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
92STS Posted July 3, 2006 Author Report Share Posted July 3, 2006 Belt tension is in accceptacle range. Radiator is full. Took it for a ride down a back road at lunch. It is not shifting, hence the down on power feeling.(It starts off in second gear) You can manually put it in first to start off but it will not shift above second gear. There seemed to be some debate on here whether the 4.9 had a limp home mode or not. This appears to be some sort of limp mode however the fact the instrument clusters don't work concerns me as there is no way to self diagnose. Could I have had two unrelated problems happen at the same time? Of course, that would be my luck. If I can find my 5/16 socket, I will check the connections on the PCM and PROM. The ground appears to be OK. I did run a jumper ground to the block. I also ran the battery charger on "start" and ran the car. No change. The comical part is: I build very high horsepower race engines (3000 HP)yet after working on my own car for two days I can't get it to idle right or even get out of second gear. Very humbling. Link to comment Share on other sites More sharing options...
adallak Posted July 3, 2006 Report Share Posted July 3, 2006 No limp home mode for 4.9. The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
92STS Posted July 4, 2006 Author Report Share Posted July 4, 2006 No limp home mode for 4.9. Thanks Addalak, knowing there was no limp home mode, I went back and double checked all the grounds and the maxi fuses. There is was, the fuse was OK but the recepticle was all corroded. Cleaned it up and all is good. It was a 60A fuse in the "IGN 3" location. By the way the car was shifting, I just did't get it going fast enough I guess. Thanks again for your help. T. Link to comment Share on other sites More sharing options...
adallak Posted July 4, 2006 Report Share Posted July 4, 2006 No limp home mode for 4.9. Thanks Addalak, knowing there was no limp home mode, I went back and double checked all the grounds and the maxi fuses. There is was, the fuse was OK but the recepticle was all corroded. Cleaned it up and all is good. It was a 60A fuse in the "IGN 3" location. By the way the car was shifting, I just did't get it going fast enough I guess. Thanks again for your help. T. PAUL_T nailed it! Try another thermostat, 218F on a highway is too high for 4.9 engine. The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
GreenMachine Posted July 5, 2006 Report Share Posted July 5, 2006 check to make sure your fans are all spinning. On my moms old 92 deville with the 4.9 I remeber these sames symptoms and the fans were not turning. (they got stuck or something) the guy at the local shop did something real quick and all was well, he freed them up or something. I was young at the time so its all a blur now. The Green's Machines 1998 Deville - high mileage, keeps on going, custom cat-back exhaust 2003 Seville - stock low mileage goodness! 2004 Grand Prix GTP CompG - Smaller supercharger pulley, Ported Exhaust Manifolds, Dyno tune, etc 1998 Firebird Formula - 408 LQ9 Stroker motor swap and all sorts of go fast stuff Link to comment Share on other sites More sharing options...
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