Originally Posted by XTroyX
Well... father in law ended up accidentally leaving key in car on the on position all night and the Bonneville was dead this morning. After charging the battery the car has started and ran at idle for up to 30 minutes three times. I've thrown on the ac, radio, lights to put a load on it and it ran great. I put the gas to it several times and held it at 2500 rpm'* and it ran great. Still not ready to take it out on the road due to how hot it is here. Over 100 degrees today. I stopped and bought a Haynes book but the relay info and pictures they show are not the same as my car. I'm not sure which relay is for the fuel pump. We've disconnected them all and put them back and now I'm wondering if by letting the battery go dead is it possible that the "computer" or electrical system, relays or whatever you want to call it has reset? Does anyone have a decent picture or diagram of the 95 Bonneville relays? Not sure where to go from here. Thanks again for all your help and suggestions.
OK. It'* just one opinion, which should be just one consideration for your troubleshooting, but I have a real thing about the ECM/PCM in the '95s. I have had my '95 SE, the far longest of the 3 Bonnes I have kept on the road, and it has proved to be an invincible brick. It has 210,000 mi and i have no reason, at this time, to believe it won't outlive me.
The car has liked to go through wheel hubs and headlight/twilight switches. But the rest has been few and far between, and stuff you would expect.
The disasterish problem was the one i mention in this post. And only because the PCM fooled me.
A lot of research told me which symptoms need to be checked at the PCM, before you go on a big chase on a '95. It'* $20-30 and can save a lot of time to have a spare.
The "mystery cut out" is the #2 on my list. #1 is the CE light, with a DTC for some failure in the ignition circuit.
I think I got the hint for the problem from 95naSTA(Mike). He has always been very savvy about how the PCMs are programmed. The real machine-level language stuff.
IMHO, the weakness in the '95 PCM is the result of a quicky work-around. The '96-'99 PCM have a complex set of Series-II work-arounds for spark/fuel/air issues. The '95 has one. I call it the "get you home alive" program. In the presence of a skewed value (and maybe a DTC code), the PCM just modulates everything to keep you from doing serious damage to the engine. It'* an incredibly inefficient running condition, but not a bad defensive idea.
The problem is that this program has a disruptive capability to the PCM, and you end up getting weird output from the PCM.
The dead battery, with things then kinda returning to normal, just smacks of the PCM.
1995 Bonneville stalls (fixed)