clean the injectors

 

yea, i've tried injector cleaner. few different brands. and cheap gas to high octane fuel

 

My 98 2.2 5 speed is doing basically the same thing....it will buck/jump once or twice when accelerating up thru the gears around 2000-2200rpm...runs fine if I slowly accelerate thru the gears but will start the bucking if I have a slight load on the engine like climbing an incline while changing gears or even when passing a slower car...If i have to let off the gas some before I go around a slower car it will do it when getting back on the gas to try and pass... I notice it more in the higher gears 3rd thru 5th

Does this sound like injectors? Seems all this started shortly after running Sea Foam thru the brake booster (1/2 can or so) then the rest in my tank...I replaced the fuel filter about a week ago too trying to see if it might be my problem...but with no luck.

 

Have you started to replace any parts yet other than the fuel filter? I have done the fuel filter also... ...and no luck. I'm not sure it's the fuel injectors. Do you have any codes?
I was thinking about replacing the control module under the coil packs. I really don't know if that's gong to work. Throwing parts at problem is $$$$. I just need more ideas to fix. 1000's of 4 bangn s10 owners I sure someone has answers.

 

check your fuel pressure, if its too low this can happen.


also try replacing the TPS sensor, i've had mine go out and it caused this exact problem but it also would throw a code ( 00' sonoma)


otherwise check the plug wires and plugs etc. etc. that should also throw codes as well though due to miss fires

 

So I pulled the K&N intake from throttle and sprayed a little sea foam deep creep into the throttle body. cleaned a bit let sit for about 5 min and started up. Good puff of smoke. Test drove about 30 min and cleared up problem about 70%. should I try this agian?

 

i have the exact same problem, new plugs, wires, fuel filter, and fuel pressure regulator, i think it might be something to do with either the TPS or an O2 sensor

 

It's not the O2S, the truck goes into Open loop at WOT.

 

sounds like a fuel pump to me

 

o.p said the fuel pressure is good, wouldnt it be low if he did the check?

 

Hate to revive an old thread, but I'm have alot of the same problems on my 95 2.2. The idle is steady, maybe a little rough but not too bad, but when i'm driving and get on the gas about half throttle or more, it will start bucking and acting like it has no power. If I let off a little it will clear up. I put the new crate motor in the truck about 19,000 miles ago, along with a new delphi pump and sending unit, ac delco plugs, wires, egr valve, and iat. I have noticed a ticking/rattle when I start up in the morning, that seems to get quieter as it warms up, figuring a timing chain tensioner, gonna knock that out this weekend. Sorry for long post, thanks for any help.

 

replace map sensor I have a similar problem and change some expensive parts and it doesn't trow any code

 

hmm the ticking could be timing stuff or lifters but with 19K on a new crate it shouldnt be lifters.

the no power could be the ICM (Ign Control Module - thing the coils mount to). they usually get wonky as they warm up. With the engine and everything cold does it bog and hesitate or only after its been running for awhile? Autozone tests these for free when you bring em in so cant hurt to test it (pricey to just swap)

it could be TPS (throttle position sensor)... what all did you have to swap from the origional engine to this crate motor?

 

You guys need to get your truck(S) on a scanner (and road test it) so you can see the TPS output, and the fuel trim numbers, and the MAP HG; unbolt the CAT; check backpressure; injector balance test; coil; spark; ECT all of the stuff makes a difference in Drivability.

This stuff about, "it runs rough" is almost impossible to diagnose over the internet.