I recently aquired an 88 S15 Jimmy with the 4.3v6 4X4 two door mud machine. I bought it to drive across flooded rice fields to duck blinds. Still think I got good deal at $500 with new mud tires, but I am having some issues with it. When I got it it wouldnt hardly pull itself down the road and was missing badly. I found 2 sparkplug wires off, replaced them and it rund like a champ. 300 miles later one cold december morning, it started up and died and wouldnt restart. Sounded to me like it flooded out. Was blowin a lot of black smoke out when it was tryin to start. I put an EGR valve, and a map sensor on it as well as reran all the vacume lines. It started back up afterwords but blew out a lot of black smoke. Thought i had it fixed but its done that to me a couple of times since then when the temp was below freezing. Several times when I was running at speed down the road it started stumbling like a carbed engine will do when its flooding, so I floored it and cleaned it out and it would run fine for a mile or so but then start dooing it again. It really wants to idle high and it tends to want to fill the cab with fumes like its running rich. It has a throttle body and its an automatic trany. I thought that maybe an o2 sensor could be bad? I am not sure about the fuel pump, havent checked that but dont know how much pressure a TBI needs. To change wouldnt be much trouble cause I will cut a hole in the floor if thats what it needs. Any thoughts would be appreciated.

 

Do a search to start with, and get your OBD1 engine codes with a paperclip or elcheapo beep scanner and report back. TBI fuel pressure is about 13-14 I beleive. Diagnose before throwing parts at it.

 

Thanks for the reply. I was logging back on to ask were in the world the diagnostics port was at on that thing. I have worked on a lot of vehicles and its typicaly under the left side of the dash above the drivers left shin. But I have looked all over this thing and cant find it! I have finally convinced myself that somebody cut it off for some reason. Would anyone no for sure were its located?

 

you're looking in the right place.

but before you say somebody cut it off, take a good look up under tha dash. i've picked up a few trucks where it had been unscrewed from the lower panel, & then stuffed up unto the wiring under the dash.

it almost sounds like a FPR issue

while i always do a complete tune-up & fluid change on every vehicle i get, when i get it, you never mentioned what (if any) maintenance you've done to it.

and that would include any/all filters as well.

see about getting those codes, then report back what you find.


***edit***ok, i found what i was looking for earlier.

you can get your codes figured out HERE.

i knew who it was, but i just couldn't remember where he had the info stashed, and i reeeeeally didn't feel like typing all that out-especially since i knew it was around here somewhere.


ok, i gotta get a few ZZZZ (kids are up in 2 1/2 hrs)

plus i had to correct the speeling on half of what i just put up!!!!!


GL with your diagnosis.

 

thanks for the info. Now that I know its there I will pull off the lower dash and see what I can find. I have looked extensivly under the dash already so I think thats the next step. Engine light comes on from time to time but goes off shortly usually. a couple of times its stayed on for a couple of days. If I cant get this thing figured out I am ripping out all of the electronics on the engine and dropping in an ol carb and DUI distributer.