4.3 running like crap....need help asap!!!!

also check for vacuum leaks or intake leaks, and check spark plugs and wires, could be missing/skipping on a cylinder or 2.

check your tbi

well i tokk it to a shop for diagnostics and they told me it was the fuel pump....well 70 bux later plus his fee its not the fuel pump....what a fuckin waste...i noticed that the oil pressure gauge isnt workin and the check gauges light is on, but no CEL, according to my repair manual it says theres a common oil pressure switch that is tied into a fuel pressure switch that apparently cuts fuel at low oil pressure...im almost willing to put money on it that this is my problem, but im not sure though and im broke...haha...the main thing is that there isnt any trouble codes bein thrown so its obviously hard as hell to diagnose the problem, and i can afford to keep throwin parts at it....

if you want, bring it by the shop I work at in Galena Park off of the 610 on Clinton Dr. we can get it fingered out for you and let you know exactly what it is before throwing parts at it, pm me if you wanna drop by

I had one of these in my s10. Check to see if both injectors are spraying evenly. Just pull the air cleaner completely off and start it up, i had to change one of mine with a similar problem. if you need to get to the fuel pressure regulator, you need a torx or allen driver (i dont remember exactly which) and pull the top of the throttle body off and 4 screws hold it in. a tbi setup is essentially a carb with two electronic sprayers on top. if i would have keep mine, i would have changed it to a carb. its about a $300 conversion

Edited: 9/16/2009 7:17:01 AM by draggin95niss

ok if it a tbi motor ur regulator is not undert the intake plenum because there isnt oneif it doesnt have a fuel filter check ur injectors they are probably clogged 

i was in the same situation you were.  i traded for a truck out of lousiana that the guy was totally not honest about.  i drove 6 hours outta Kentucky to meet this idiot.  anywho........i traded for a 99 sonoma with b22000vortec with only 61000 miles i thought how the hell could i go wrong trading a 87 b2200 with 160000 miles.  well someone had tried to move all the wiring and fuse boxes under the dash and then just cut out a bunch of shit........hell it looked like someone closed their eyes and started grabbing and cuttin wires.  so i bought a complete harness and swapped them out and it was  just running like shit...........basically just as you described with your problems.  i scanned it and it kept throwing different codes and i could change the part for whatever code.  i ended up replacing  damn near all sensors on the motor. nothing seems to help.  it wasnt reading any codes and i wasjust about to burn the damn thing.   well the harness i got came out of a 98 blazer which i was told it was the same harness  and it did look the same,  but the transmission harness is different...... so i couldnt figure that out. so now it runs like shit and it wont shift gears after i worked for 4 months.  so i decided to take it to a local transmission shop to see what they could do for the tranny.   well as they scanned it to see how the solenoids were firing it threw a code which was the mass air flow sensor well that was the one of the only things i hadnt tried.  so i thought fuck it i will try this just to see.  sure enough i changed that maf sensor and she runs like a dream.    so check that and see what that does for ya.  im sorry you got riped off and hope he gets his in return.....i have been there and it sucks balls.  hope i have been of some help and you get ur truck lined out.

Edited: 9/16/2009 7:17:54 AM by draggin95niss

well a new fuel pump, fuel filter, and a set of plugs later turns out the timing was just a little off.....thanx for all th einput guys  .....