car breaking up past 3500/4000

[slowhatch82]

OK update, i have ruled out:
fuel filter, plugs, wires, coil, secondary ignition, fuel pressure, fuel injectors, rotor is fine, cap is fine....what else could i check...

im checking the ignition module today.

 

[85_SS_302_Coupe]

Could def. be the injectors, could also be a timing/spark issue as well. Higher RPMs require stronger/more often sparks, so an MSD ignition box or something like that would probably help, not to mention a good tune up. I'm just guessing but i'd think if you had 2 injectors that were bad you'd be cutting out at low RPMs too, but who knows. Also totally off the subject, i see you probably had an 82 GT at one point?? Any advice on where to get the '82 GT front bumper cover? I want one like the pace cars had but they're hell to find....thanks.

 

[slowhatch82]

yeah i thought the same thing, but maybe they just provide enough fuel for driving around, and but doesnt at wot? i dont know....

about the 82, i was looking for one myself, mine had a crack in it! they are very hard to find, keep your eyes open inthe classifieds on corral.net and the classifieds here....goodluck

 

[slowhatch82]

can anyone else give me some suggestions?

 

[DavidF]

I suggest you buy new injectors.

 

[HISSIN50]

ill throw out some ideas. if you have platinum plugs they can cause cutting out at around 4K. if your pick up or coil is goin out, they can cause high rpm misses. also , check your fuel pressure when the car is revved up. if it drops, pump may be on its way out. check the FPR out as well if this is the case (low pressure at rpms). a flow test will tell better if this looks like the culprit.

i am not that experienced with injectors, but i would think they either work or dont. just my thoughts. you can do a goose test to have the puter test injectors while pullin codes.

good luck.

 

[bmo37]

repalce the pickup coil (stator assembly) inside the distributor, if that doesn't do it change the tfi module on the distributor.

 

[slowhatch82]

alright, i work at a parts store, so i can probly try some stuff out

the fuel pressure is good, i had a local shop test some things....they said the secondary ignition is all good, the fuel pressure is good, some injectors leak...and my uncle said that the injectors click, and he said 2 of them werent clicking right, you can put a screw driver on them to count the clicks or somthin..

i have injectors with 50k on them...so ill throw them on there first...

anything else that might be the culprit?

 

[HISSIN50]

alright, i work at a parts store, so i can probly try some stuff out

the fuel pressure is good, i had a local shop test some things....they said the secondary ignition is all good, the fuel pressure is good, some injectors leak...and my uncle said that the injectors click, and he said 2 of them werent clicking right, you can put a screw driver on them to count the clicks or somthin..

i have injectors with 50k on them...so ill throw them on there first...

anything else that might be the culprit?

your uncle is right. normally, properly functioning injectors will click when working. i would confirm that they are getting juice (electrical) - they wont click if there is no pulse to them. noid light works.
was fuel pressure ok at high rpm?

as i mentioned above, you can do a goose test. i bet the sites jrichker recommends outline the test. if not, i can post it (i just follow the stuff in the book that came with the code scanner). it will tell you which injectors are not working and you can run the test a few ways to narrow things down.
good luck.

 

[slowhatch82]

alright, i pulled the injectors yesterday, put in all working ones with 50k on them, and it runs the same, these dont leak, so at least it was still worth it....

what else could we do here? clogged fuel filter?

anything else i could check?

 

[slowhatch82]

im going to go out and double check the plugs now, maybe i will find somthing!

 

[JARED FOURNIER]

I had this exact problem with my coupe when I first bought it. It was either the coil or the ign. module. I can't be sure because I replaced them at the same time. I had some known good ones in the tool box and because it was getting late and the guys were already closing the shop I swapped them both out at once(no time to try one them go on test drive and then try other). I'd be willing to bet it was the coil. But this was after diagnosing out fuel and tune-up problems(fuel pres., plugs and wires, cap and rotor). I doubt it's an inj. problem I've never seen one miss only at higher rpm. in my experience if an inj. is bad it either has an open coil, high resistance through the coil, no pulse, or the pinttle is stuck, in all of these cases the inj. is effected all the time not just at higher rpm. I'm not saying it can't be an inj. but IMO it's unlikely. Good luck!!

 

[stang22]

im going to go out and double check the plugs now, maybe i will find somthing!

What kind of plugs are you using and what do you have them gapped at? About a year ago I had the same problem with some plugs I thought were good ones. I would get a miss around 3k rpms'. Long story short, I installed some Motorcraft plugs and no more miss. Definatley change the fuel filter if you have not already.

Tim

 

[Carney Woods]

I'd change out the fuel filter before anything else.

 

[slowhatch82]

alright, just got back in, changed the fuel filter and plugs, runs the same....

when im revving it, if i just try and hit it, it will stutter, if i take it up slow it doesnt, same thing as before.....the car just doesnt want to go anywhere...

ill give the coil a shot...

 

[slowhatch82]

negative onthe coil, they ordered an ignition module for me, so ill try that tommorow...

 

[slowhatch82]

updated....read first post

 

[bmo37]

i said tfi and stator assembly (pickup coild) not ignition coil. Thats what it was for me. I kept blowing my pickup coil in the distributor so after 3 tires of the pepboys replacement i just replaced the entire distributor with a msd and never had a problem ever again. Went the same route as you, I did a complete tune up, spark plugs, wires, airfilter, pcv, fuel filter, had injectors serviced, ignition coil, ect sensor, o2 sensors, tfi module, and pickup coil, finally went to msd and never happened again.

 

[Antigen351W]

Hmmm, I've had a similar problem with my '92 GT. Let's say I'm racing someone. At around 35.0-4K, the car starts "skipping" and you can see the tachometer hand bouncing up and down. This only happens under WOT. If I slowly rev it past 3500-4000 rpm, it won't do it, or if the engine is cold and I crank it up, take it down the road and get down on it hard, it won't crap out. But after it warms up, it'll do it. And yes, I've changed most of the usual stuff and checked TPS setting and no change, so I'd like to hear the answer to this problem as well.....

 

[Cobra1894]

I had this probelm before as well. I dropped my timing back down 10* and no more skipping. seemed to do the trick for me.