i don't know

im not to familiar with the 4.3 but first go ahead and check the easy stuff like fuel filter or spark plugs and wires and ur timing. if not one of those problems then the best thing would possibly replace ur 02 sensor or mass air flow sensor. like i said dont know to much but its simple things to check before actually having to tear crap apart.

Ya i guess it seems to sputter and kinda miss here and there like its not gettin enough gas or not runnin on all cylinders. I just wish i was more engine savy, i was never taught about them so dont know much. I guess me and my buddy is gonna replace plugs/wires, fuel filter, and possibly dist cap/rotor tomorrow if I have time. This blows!

how does the oil pressure look on the gauge? some of the s-10s have a safety on the oil pressure sending unit that kills the fuel pump when there is very low oil pressure. my roommates blazer was sputter off the line a little bit and the gauge read low, replaced the sending unit, gauge readings are high and it seems to run a bit better

loosen your distributor just enough that you can move it and start the engine, then slowly turn it left or right until it falls into a nice rythm, youll be able to tell when its right by the sound, the best way to learn is by trying things and asking questions bud

Well guys I'm still stumped. Today I replaced the spark plugs/wires, fuel filter, changed the oil, and sprayed a whole shit load of carb cleaner into the intake but still no fix. Just doesnt run like the day I bought it for some reason. One guy suggested the fuel pump?? Hopefully if I keep updatin this forum then someone who has ran into the same issue could give some input. I'll pray haha

Sounds like you still haven't checked the timing...is that right? The most probable cause of your problem is gonna be timing. Is your DTC light on? If it is, check the codes, that'll tell you loads. Low fuel pressure (faulty fuel pump) is gonna trigger a code. Same with low oil pressure...but check to see if your truck even has this failsafe. Good luck!
Oh, add a bottle of HEET to your tank, it might be excess water in your fuel, seen that once.

just a question cuz im not to familiar with fuel pumps but im gonna go ahead and say its an electrial pump so the question is wouldnt it just go out with no warnin, no spitin or anything? no it sounds like a dumb question but i just wanted to ask. but as far as the guy with the problem ur best bet is to go ahead and check ur timin and if that aint it take the motor out and drop a 350 lol. but seriously go for ur sensors next

Originally posted by ascension11



Sounds like you still haven't checked the timing...is that right? The most probable cause of your problem is gonna be timing. Is your DTC light on? If it is, check the codes, that'll tell you loads. Low fuel pressure (faulty fuel pump) is gonna trigger a code. Same with low oil pressure...but check to see if your truck even has this failsafe. Good luck!Oh, add a bottle of HEET to your tank, it might be excess water in your fuel, seen that once.

i haven't checked my timing yet but i don't understand how that would have got thrown off.

MAF sensor and/or o2 sensors should be looke at.

I thought your problem was fixed. Anyhow, any modification made to your vehicle can alter necessary timing adjustment. We don't have all the details, and just like any mechanic, can't diagnose for sure over the phone...in this case, over then net. Your threads could be stripped on the clamp, you could have changed to a cold air intake, who knows. There's a list of things that need to be checked anytime your having a problem like what you guys are describing. Like it's been suggested before, timing, MAF (wouldn't touch, really), O2 sensors and their wires, you can check the fuel pump by jumping terminals in your OBD Data Link Connector. Fuel pumps have built in check valves that allow your system to stay pressurized, that may be faulty and causing your system to have to be reprimed each time you go to start your truck. Your probably just gonna have to take a day and go through a checklist of things till you figure it out.