Full Throttle/car Falls On Its Face

[Foxslider]

I inspected/cleaned the MAF sensor wires since it was a easy task. Did'nt look very bad at all. Did'nt have O-ring on it, so i used some gasket maker to seal it up.

Mine did this a couple years back. I chased fuel and TPS and it seemed to solve it, but then come back a few drives later. I change spark plugs, and spark plug wires and cleaned all sorts of connections and sensors.

Ultimately it ended up being the ignition coil. I had a 20 year old Accell coil on there. I swapped it to a good, used OEM coil on a hunch and the problem went away and never came back.

Symptoms were that when I went WOT, when I got to 3000-3500RPM, it's like the car would hit a wall and fall on it's face and not accelerate anymore. I had no codes, no misfire.

I do have a sketchy plug going to the coil. Could be a bad connection. But the wires are connected firmly. You know, unless X amount of fuel was going thru and.... but nvm. B/c it works sometimes and sometimes not. That's what throws me off. If it was consistent id say clogged fuel filter potentially. But no.

 

[90sickfox]

The pick up in the distributor can do that. MSD distributors are famous for it because moisture gets in the bottom area where the pick up is. You can usually tell by a white ashy look to it. A bad coil with do it too. Under load they can start to arc ro the its body. Start it in the dark and look at it for arcs. Those 10 pin connector wires can be straight wired....deleting the troublesome connectors.

 

[Foxslider]

Test drove it, Acted the same. Cool, I just took the plug off the coil and straight wired it. (marked it also) I'll throw a new TFI, cap, rotor on it and go from there.

 

[Foxslider]

Did the TFI. Right before i did it, car ran strong for first time in 2 days trying over 10 different times. B/c i shut it off and start it and it works sometimes.

It is better, but it fell flat once when i was trying timing adjustments. Went back and got it pretty good. Not falling flat now, yet. But at 80% power at full throttle it feels like.

Gonna do a new fuel pump next. Probably not the problem, but im sure the old one is old and cant hurt.

 

[Foxslider]

Here's the codes i got from code reader

Motor off:
10 - not listed
14- Ignition profile pickup (PIP) circuit failure
22- MAP or baro sensor out of range
31- (cars) EVP or PFE circuit below min. voltage (trucks only)- EGR valve control sensor fault
41- HEGO (HO2S) sensor voltage low/s ystem lean
66- VAF/ mass air flow sensor fault, below minimum voltage
96- fuel pump secondary circuit fault/ high speed fuel pump relay open

Motor on:
6- not listed
21- cooling temp sensor or ECT out of range ( ran the test with a warmed up engine)
31
41

 

[Foxslider]

Put a new distributor in but no luck. Returned it b/c no point in keeping a new part if it does'nt fix my problem. Normally i would. But just being cheap. I wanted to keep it though. lol.

Will do fuel pump next. I doubt that is the problem, but oh well. After that i'll take it to a shop and see what they say.

 

[Foxslider]

Checked fuel pressure. 33 at idle or so. 40 w/ FPR vac line off. Did drop to 25 when revved.

 

[Foxslider]

New oreillys pump in. New (K&N ive had) fuel filter. Car rips. Running better than ever. No miss at all now. Full power back. Stoked!