Needing some assistance with what I feel to be an ignition issue.

[Blakonblak94]

So as of lately my car has been giving me some fits. It seems that it will hesitate, and buck, under full throttle underload, above 4000 rpms. Say 1st gear full throttle, right around 4000 rpms it will begin to break up and surge and if I continue to hold down the throttle itll eventually pop through the exhaust similar to a backfire. I checked to see if it was a dead spot in my tps, thats a negative. Im not really sure what to check or what it could be. I thought it to be clutch slipping several months back, ha wrong, and now Im really beginning to get concerned. If someone can help me in the least Id greatly appreciate it.

 

[HISSIN50]

The TFI and coil are two possibilities.

That's assuming you don't run platinum plugs (which can also cause a miss at about 4K).

Any codes?

 

[CC'S95GT]

I just had a hi RPM miss and after a tune up and a new coil the miss went away.
I did still have the oem coil in the car at the time.
Pull codes first, give it a good tune-up, let us know

 

[Blakonblak94]

Ill pull codes this afternoon. Im running autolite coppers, no platinums.

 

[mikey94gt]

Are you running an ignition box? how bout engine mods? these cars have somewhat weak spark after about 3800, and they start to break up pretty bad, and aftermarket heads/cam magnify the problem.

As a thought, how old is your dizzy cap/rotor, and plug wires? check the coil post too, they like to corrode, leading to misfires.

 

[95boss351]

I know that happened 2 me once and found out that my fuel pressure was low and i was running lean and i had 2 change the fuel pump. U might not have that same problem but im sayin it could be a fuel and air problem

 

[Blakonblak94]

Ok here is some background. Twisted wedge heads, trackheat intake, mild cam, 24's with a pro-m maf. 255lph pump with kirban fpr(which i need to check). car has 86k miles. All stock electronics, probably even has factory wires. Terminals under the rotor have some corrosion on them. But the problem has been slowly making itself more present it seems.

 

[Adam95GT]

Can you look at your datalogs and see what the HEGO's are reading??? my car is doing similar.

 

[Blakonblak94]

I need to update my sig. I no longer have the QH.It no belongs to NXcoupe.

 

[Blakonblak94]

Ok I pulled a koeo code of 565 and 327. The canister I already know about but the 327 is egr code which is because the egr has been removed(fox body swap intake setup). Those are the only codes it spat out, however I think I may need to run a koer test.

 

[Blakonblak94]

And no abnormal codes with koer, just thermactor missing and egr missing. Cylinder balance test also presented nothing. Im contemplating running to pullapart tomorrow and yanking an ignition system out of a thunderbird up there since it has the remote tfi as well just to see if by chance the dizzy is bad before I buy a new one.

 

[mikey94gt]

I would do a tune up with a cap + rotor and go from there, all new ignition stuffs. these cars are kinda picky when it comes to ignition. also... see what your fuel pressure is, just out of curiosity. plus, whens the last time you did a fuel filter?

 

[Blakonblak94]

Fuel pressure is a 39 vacuum removed, fuel filter was replaced about 1-2 months ago, when I upgraded the fuel pump.

 

[mikey94gt]

cool, so its probably ignition related. I would do a tune up, especally if you have corrosion.

 

[Blakonblak94]

I'll do cap and rotor tomorrow after I cash my check. The trip to pullapart was a failure so no go on cheap parts. This couldnt be caused by my MAF could it?

 

[Blakonblak94]

So cap and rotor didnt help the situation, same thing. Whats the next possible culprit? The pip sensor?

 

[BLOWN 95GT]

Mass air meter could be dirty or going bad. I never had a pro m meter that wasn't junk! I would try to swap meters with a buddy for a few minutes or so before I went and bought a new one but if it ended up being bad I would buy a C&L.

 

[Blakonblak94]

MAF is clean, I dont have any buddies I can swap meters with. Thats what sucks ha. But the way it feel reminds me of when I had an issue playing with my flow chart when I had my QH and I changed my parmeters incorrectly. But I still feel like its ignition, similiar to rev limiter/fuel cut is the best way to describe what is occuring.

 

[BLOWN 95GT]

How long has it been since you changed the fuel filter, and fuel pump?

 

[HISSIN50]

He did the fuel filter a month or two ago.

Since you don't have a spare coil or TFI module to swap in, you could try having a parts store test your TFI.