help me havin cut out probs at high rpm!!!

[jimerson503]

hey guys i have a 94 gt mustang 5.0 stick just got done doing a gt40p swap stock everything else but went ahead and done some igntion work too all msd cap rotor street fire wires street fire coil but know it cuts out at 5000 rpm im think the dizzy maybe anyone else have this prob

 

[302GTS]

By cutting out do you mean breaking up and backfiring? Like popcorn out of your exhaust? If so, that's the distributor. PIP to be exact. I just had that issue a few months ago. Putting in a new dizzy solved it.

 

[jimerson503]

ya sorta it just like cutts out and has no power thats what i was thinking just didnt wanna go buy a new dizzy and that not be in... what kind of dizzy u go wit

 

[302GTS]

Well, funny story. I replaced mine with a Summit brand one, and it took a **** after 3 months... Swapped in a friend's stocker out of his 95 with 80k on it, and it's worked perfectly for the past few months.

Having no power and breaking up sounds like a plug issue possibly... When I bought my car it had a set of Bosch platinum plugs in it, mileage unknown, and my car started falling flat on its face at around 4,500 rpms. Changed plugs to Autolite coppers 4 months ago, and the issues been gone ever since. Pulls smoothly all the way through the powerband now!

 

[HISSIN50]

As Jeff noted, plats can cause a high RPM miss.

It started doing this after swapping coils? If so, do you have your old coil? If you do, toss it back on and see if the issue abates.

 

[LethalInjection]

Do you have stock valve springs on the 40p's? It could be valve float.

 

[Black95GTS]

I'd be looking at the ignition coil or the PIP for this one. Valve float is possible but I wouldn't expect to see that for at least another 500 rpm.

Adam

 

[Venom351R]

Does it do this?

YouTube - 1994 Cobra Mustang Break Up at 4,000 RPMS


That was a bad Mass air meter on mine.

 

[LethalInjection]

I really don't think it's float either but I did have a strange issue with harmonics when I was runnin a b303 with stock spring e7's. It was just like a weird miss or rough spot around 3k. I had no idea what it was until I changed to my heads now with mouley springs and it disappeared. Now Im pretty sure he's still stock cammed but I'm not sure if the explorer springs are weaker than the e7's or not but I think the ho cam is more aggressive so that's why I threw that out there just in case.

 

[revhead347]

+1 on putting the old ignition coil back on and checking it. The stock distributer has always seemed to work the best.

Kurt

 

[jimerson503]

thanks alot guys still havent found the prob but im in uti so im gonna take it to school tommorow and have the ford teacher F*** with it and see what he thinks im gonna check my mass air its a new mass air but i dunno ill figure something out. thanks guys taking all the help from u guys

 

[jimerson503]

and guys sorry for sounding dumb but whats the pip ?

 

[94GTCoupe]

and guys sorry for sounding dumb but whats the pip ?

Posted via Mobile Device
profile ignition pick up.
also called stator assembly.
inside the dizzy.

 

[jimerson503]

ight thanks boys i cleaned the mass air and changing the plugs back to copper thanks for all the help when i figure this sh** out ill let ya guys knw my probs

 

[Chythar]

One of the main issues I have with Ford diagnostics is that multiple parts could be causing he problem. and not just one, sometimes it's 3 or 4. I've had a rough idle on my GT for a while. I did a general tune-up first; replaced the spark plugs, plug wires, and distributor cap & rotor. I also replaced the coil and tfi module while I was at it. The idle improved but was not as smooth as it should be. So this weekend I replaced the pip in my distributor and re-adjusted the idle. Yet again, the idle improved but is still a bit rough.

My point is, several components could be contributing to the problem. Everyone's suggestions are possible causes, so you'll need to hit up one at a time and see if any of them help.

 

[302GTS]

One of the main issues I have with Ford diagnostics is that multiple parts could be causing he problem. and not just one, sometimes it's 3 or 4. I've had a rough idle on my GT for a while. I did a general tune-up first; replaced the spark plugs, plug wires, and distributor cap & rotor. I also replaced the coil and tfi module while I was at it. The idle improved but was not as smooth as it should be. So this weekend I replaced the pip in my distributor and re-adjusted the idle. Yet again, the idle improved but is still a bit rough.

My point is, several components could be contributing to the problem. Everyone's suggestions are possible causes, so you'll need to hit up one at a time and see if any of them help.

+1 If you've got the cash, feel free to replace as much as you want! It won't make anything worse.