imported_blade

so far what i've done to take care of my misfire (ya the same one i posted about like two months ago) is this:
rebuild the distributor (everything but the module)
replace spark plugs (twice)
new plug wires
new cap & rotor

wired new injector clips (from the wiring harness to the injectors)

and i'm still misfiring!!
so my question is this:
today i was messing around under the hood, trying to find something, a lead, as to what might be causing my problem. while playing around i was checking the injectors and noticed that when the cylinder fires, you can feel it in the injector clip (the plastic clips i have replaced). so i went around to every cylinder and i can feel the little jitter (i guess) on every injector except for the #7? (driver's side, closest to firewall) cylinder. That one feels like absolutely dead. My car seems to run well enough that i think that cylinder fires most of the time, but i think this may be a good lead to pursue. so, is this a likely cause to my problem? or am i chasin a dead end? are you supposed to feel the little vibration on the injectors?

ps, my miss seems to be most under load (accelerating from a cruising speed, uphill, etc.) I can cruise at a consistant speed and have no noticable problem. only when i try to accelerate from that speed.

69z-28

DNA383 has a problem kinda like that. been trying to figure it out for a while now. his computer was fried and he changed that but still messing up, and thinkin its the MAF because there was no reading coming from it when it was scanned, so hes thinking about that now, but before when it was running good it was only running on 7 cylinders ALL the time. now it runs on 8 but starts missing under load. anyways he changed the injectors and the car ran on all 8. VERY possible you need new injectors. get them tested or something. Summit has FMS 30 lbs injectors for 230$. depending on how big you want to go, or if you want to go with factory size. just make sure you dont get accel.

archemedes

sounds like that injector is at least weak, see if you can swap it with someone elses known good one (even a junk yard part) also check the module (that's the first thing to do to a gm hei, that module has somewhere near a 70% failure rate, and don't get the advance one I went through 5 on the the bravada spend the extra for a good one)

imported_blade

i've got injector cleaner running thru the engine right now. after i empty the tank, if it doesn't improve i'm gettin' a new injector.

Dna383

when does this problem happen (Under load, always, when you first start it) mine is usually only under load. i am on the 2nd computer, 2nd set of plugs, 2nd set of wires, took out the msd coil and tried the stock one, 3rd module, and i just orders the esc box. check ur timing, do you have an adjustable timing light or timing tape?

Dna383

because you need to check your total timing (timing with full advance, leaving the timing wire on the firewall connected, at around 3000 rpm) it should be about 33 degrees advanced. if it isnt then the computer isn't advancing your timing (your only getting the mechanical advance). i would also check your injectors. i thought i was only running on 7 cylinders because of ignition problems, but it was my injectors that were bad. i would also check your fuel pressure while your driving. it may be fine at idle in the driveway, but under load it is different so if you have access to a gauge check that (run the line between the hood and the cowl and tape the dial to the windshield. if at full throttle you aren't at about 47 psi your fuel pump may be shot. just a few suggestions as i have had the same problems. mine only happen at full throttle while under load, it sucks, makes the noise of a transbrake.