I will try and keep this as straight forward as I can.
My bonneville has been acting up pretty badly lately. It seems like its a problem that use to be hardly there, and has gotten worse.
It runs/idles well in P or N, but when its put in gear (foot on brake) it fights and stumbles. It accelerates like garbage, but it seems like you can power past it, and most times it will run nice when forced to work hard. As soon as you maintain speeds, it then starts to stumble. When it stumbles and runs funny, the volt gauge starts to flip out, and my lights etc dim out.
We assumed it was electrical, so we tore into the wiring harness, and found/fixed about 6 cracked up wires, and the lights were brighter, but it still ran crappy.
We went it again, and found the leads into the tranny had 2 fully broken off wires out of 4. We fixed those, and now it idles better in gear, but you have to tease it to work. Hit the gas...stumble...let off hit the gas, and hit it again ....stumble.... repeat again.....it drives like a charm......well for a moment..... lol
It feels a lot like when my neutral safety switch was out of wack, but it happens in any gear. It feels like driving a standard, and going from 1st gear right to 3rd, then toughing it out till you get up to speed.
We have checked all 3 coils (5.6x on each for resistance)
The wires are all new (but we re di-electric greased them again anyways)
Checked plugs (smelled gassy but other than that they had a healthy color to them (they were new with the plug wires, with under 1000km on them))
Air filter is clean
Vacuum lines seem good
changed the alt (from my new bonneville one to the one from my 95 olds)
Checked battery wires from battery to starter, all starter wires, and every ground I could find.
Pulled up my carpet to check the ground bus, but short of some light dust under there, there was no signs of wetness or anything bad. I never checked it as a result. Should I? I didn't check the passenger side (there is one there also right?) The passenger door in that car is used like 50 times a year tops.
Tested the TPS and it seems fine.
The maf was cleaned and tested this summer. (when unplugged the car dies)
Switched to a different EGR valve.
I haven't got around to checking fuel pressure, but we did test for vacuum,and it was alright.
I have no check engine light, or any other light for that matter, and I only have a OBD1&2 scanner so I cannot test it myself (damn 95s (>_<)).
Also the battery tests at 12.6v
My power steering pump pully is a little screwed up, and is causing a little noise just in case that might be pertinent information.
I made a post about this like 3 weeks ago, and thought my amp being hooked back up solved it, but it so didn't fix anything except my lack of bass lol.
Thanks in advance for any advice, as this car has fully mounted my last nerve.
(1995 Bonneville SE)