Whenever you get goofy electrical problems it is always worth checking the ground straps for the engine and the wiring harness...electricity does weird things when it is searching for a way around a bad ground.

Well it happened to me today, it didnt die, but it came close, would barely run, barely off line from dead stop too, stumbled badly, no power. This is what happened to my wife.

Started bucking, even at low rpms in the 3000 range
Airbag light comes on on dash
Check Transmission light comes on
Battery voltage gauge pegged out >16!
Squealing sound like a belt or something too, not sure where this came from. AC was OFF at time.

As I barely got back into my subdivision, the lights went off and it ran better, squealing went away, but would still buck when hit accelerator. voltage gauge back to normal.

I guess Ill pull the tranny codes. Maybe thats where the problem is. the bucking could be the TCM telling the ECM to cut out.

Now the thing is running barely when give it gas, it died on me in middle of intersection. I start it back up immediately and zoom off without a problem.

could the ecm be going bad? This isnt an intermittent problem, this is now chaos.

I disconnected the TCM and shifted it manually, the vehicle engine still bucked/surged under acceleration. Same with air temp sensor disconnected.

For a while, the R. ABS light came on, and the brake light too. After I disconnected battery and reconnected it those went away.

While I agree with Steve and his suggestion of checking grounds, this now really really sounds like the light show put on by a dying alt.

Michael

Ive checked a bunch of grounds, the ones so far have been good. There so dang many though, i doubt I could find them all.

Im starting to look at the alternator and electrical diagrams. Would a bad/intermittent alternator give severe ignition problems? What about voltage regulator?

The regulator is integral with the alt. The strange behavior you are seeing could be due to either one acting badly. At this point, and with the history of Isuzu alternators doing strange things, it would be best to pull it and get it tested. It would, at the least, rule it in/out as a problem.

Michael

after sitting a while, its dark out.

the dome light inside is so dim it looks like the battery is dead, but its not. the voltmeter on dash reads less than 12V , maybe 10V when turn on with motor not running, but battery is good, 12.65 V measured on batt terminals. Headlights are bright, starts fine. When start it up the voltage comes up to ~14V or so.

Voltage does not make for an OK battery. It needs to be load tested too.

14 at idle is also not always OK. Voltage and amperage varies under load and RPM.

Personally, I would get the battery and the alt tested for S&Gs. I would also take a very close look at your battery cables. If the ends were gross, then there is a good chance the corrosion has worked its way under the insulation and up the strands in the cable.

I would also continue checking grounds. Stick with the big ones for now and chase the others as you find them.

Good luck. This is going to take some good old fashioned elbow grease and a basic system to take a look at everything.

Michael

PS. This thing has spark plug tube right? Are any of them full of oil?

they all have some oil in them around base of plugs, but not very much. The gaskets on the tubes are bad as well as the valve cover gaskets. I have all the gaskets & common chamber gaskets I need to change them, thats what I was going to do this week while I was off work before this came up.

Bottom front of alternator is pretty oily and crud covered from the leaking valve covers, I can believe it could have issues. I think that same oil killed a starter about 2 yrs ago.

When I say battery is good, I mean its strong, cranks quickly even with headlights on, and obviously hasnt lost a cell.

Now, when I started looking at this there was some crusty stuff on top of the battery around the hold down clamp, I actually removed the battery to hose it off. the terminals were crudded up, and I cleaned them. I noticed today that the top of the battery was wetlooking too after running, and cells on part were hissing from pressure built up inside, (relief holes might be plugged up). Seems like the battery might be getting overcharged. This was after the episode where the voltage pegged out at the time the vehicle was almost inoperable.

I am just reaching for ideas for you. Motor oil and spark plugs do strange things which could account for your engine issues, but I do think there is an electrical at the root of it before we can blame a poorly firing spark plug.

Michael