need help with a 1994 bonneville
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i have a 1994 bonneville that when its first started it runs and drives great till it reaches operating temp then it will not go over 2000 rpm and will stall. 8 times out of 10 i dont get a check engine light. i have replaced the crank and cam sensors the ignition control mod the coil packs the tps and the maf. i have checked the fuel pressure running and while driving and all is good. i am kinda at a loss on what to do next. the car has 92350 miles on it. was thinking about another ecm for a hail marry stab in the dark. oh and i have checked the fuel pressure and left the gauage on while driving it and all is good. also there is a new fuel filter.
#2
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Almost sounds like a clogged cat but they typically do not vary on temp...Have you managed to scan the car when the light comes on?.Also how do your plugs and wires look?
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plugs and wires are not that old but they look fine. i have had it scaned multiple times and the only thing that shows up is the egr and one time the o2 sensor showed up but it never showed up agian.. i have a hard time thinkin that an egr could be makin all this trouble but i have been wrong before. i have thought that the cat could be pluged. i dont know but i wonder if its electrical cause that car will run on fixed peramiters till it hits operating temp so i wonder if i have some bad grounds or a bad wire..
#4
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Does the engine immediately start back up after a stall?
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Yeah it will start up and idle but it will still have the same issues and will stall again down the road. But if I let it sit and cool for a bit it will drive fine till it hits operating temp again.
#6
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I merged your two threads together..and before you go replacing the icm get a heat gun start the car when cool and apply heat to the icm and see if the car stalls out.If so replace it.just be careful not to melt any wires or anything lol
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i replaced the ecm the other day and it did throw a check engine light and i had it scanned to find thats its the oxygen sensor. but it still wont go over 2000rpm at operating tempature. anyone have any suggestions to what i should look for next?
#9
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If you are at or over 100k I'd go ahead and replace the O2 Sensors, at least the Bank 1 sensor (not that this is normal maintenance), that is the one effecting fuel trims once the car gets up to operating temps, I'm guessing since it runs at a set pre-determined commanded rate by the PCM ((Open Loop)) it runs fine, but once it warms up the system will enter Closed Loop and the front O2 sensor will change fuel trims depending on readings determined by that O2 sensor.
If you are replacing the front then you may as well replace the other one as well.
Keep in mind I am no mechanic, but I have learned a little from a few smart people, and I'm still learning daily...
If you are replacing the front then you may as well replace the other one as well.
Keep in mind I am no mechanic, but I have learned a little from a few smart people, and I'm still learning daily...