knowledgeable 5.0 guys come inside

[wick]

Problem. What would cause my car to stumble under load? Fuel pressure is good. Volt never dosent move. Autometer tach jumps when it happens. Didn't notice the factory tach. It completely cuts out them comes back. Intermittent problem too. Happened two times yesterday. Not really sure what direction to head in right now. Grounds are all good. I also didn't look at the wideband. No smoke though.

[turbo'dnotch]

Like trying to find needle in a haystack. Could be.......coil, loose wire somewhere,injector, distributor, fuel filter, etc. just try and eliminate 1 at a time. Kinda like nailing jello to a wall.:jump:

[wick]

Leaning towards distributer. Obviously if the fuel pressure does not change, the filter is not bad. One injector won't do this.

[turbo'dnotch]

Leaning towards distributer. Obviously if the fuel pressure does not change, the filter is not bad. One injector won't do this.True, but a bad wire somewhere in the harness could cause it. But your right dist. sounds like a better place to start.

[White5.0]

check coil, cap, rotor, wires, spark plugs, TFI module and distributor itself. also check TPS voltage and double check grounds and clean them

[yeahloh95]

i would try running the fuel pressure up a little bit to see if its a lean pop? try reclocking the mass air meter, just some other thoughts..

[frankstang]

Leaning towards distributer. Obviously if the fuel pressure does not change, the filter is not bad. One injector won't do this.

I was thinking distributor also. Did you check the PIP sensor for a broken or bent tang ?

[mlowry1260]

Most likely ignition related. A flaky tps can cause this too. When the tps get bad enough it's like an on/off switch.

[Martin0660]

Sorry i'm not a knowledgable 5.0 guy ;) Those damn things have too mant sparkplugs for me.

Anyway, it could also be the tach. A bad / flakey tach can take out the ignition signal as well. If you see it there but not on the factory tach that's a sign. FWIW from a 4 cylinder guy.

[wick]

Thanks guys. Silvernotch dropped a distributer off for me today. The tps is new. No spikes when opening it. I will disconnect the tach if the dist does not fix it.

[gmkillr]

How about the cheapest & fastest way to diagnose this.......code scanner, there about $20 for our cars. I have one if you want to borrow it. This could be many things, and it would be much easier to figure this out via the scanner rather than by process of elimination.........jmo.........

[lib88stang]

Had a similar problem awhile back, it ended up being a bad injector harness.

[mlowry1260]

Wick,

I have a code scanner if you need to borrow it.

[wick]

I have one also. Its a must for these dinosaurs!!! HAHAHA Anyways, I started this thread from my phone today at work not knowing of any codes in it. What I came up with was this...

15-85-15-85. Long pause, 14-66-91-96. The first series is pretty much useless to me seeing as that stuff is all turned off in the tune. But the PIP code makes me think its the dist also. I dont understand why I have a computer code unless its related to the PIP. Its in the same number if you look in the book with the scanner, Mark and Rob. Bob Myers also said I may have a bad PIP last year at the track when it broke up real bad at the second gear shift and third gear shift. Then I never had an issue again until now.

[biminiLX]

Rob, I would also look at the TFI module as mentioned. My '86 did something like this before it just wouldn't start and it was a bad TFI, which are known to go on our cars due to heat (you can relocate them off the dist.).
Hope you find it.
-J

[Martin0660]

Rob,

Don't forget, disconnecting the spout to set the timing can also set a PIP code. Clear the CM codes, drive, and retest without pulling the spout again to eliminate that.

[wick]

Rob,

Don't forget, disconnecting the spout to set the timing can also set a PIP code. Clear the CM codes, drive, and retest without pulling the spout again to eliminate that.


I didnt know that. I cleared the codes and popped in the other known good dist. If the weather holds off till 4 I will drive it to work and see how it is.

J, the TFI module was also something I was thinking. Fortunatly the other dist. had one on it. I know my Chevy truck does the EXACT same thing when the module goes bad. Change it and its good for another year. (Advance sorensen ones) There is a Motorcraft one on this dist.

[wick]

How about with the computer code? Think thats related to the PIP code? It kinda comes up twice with the two codes. Or am I just pissing in the wind here? (I actually did that today at work) HAHAHAHHAH