Hi guys, new to the forum. I don't know if I'm doing this right. Anyways,
I have a 1992 flareside that I just rebuilt the 302. Has a new cam, roller rockers, ported gt40p's, headers, etc. I used to be able to start it with the new build just fine. I don't know why but It just stopped starting. It fires and sounds like it wants to but wont. I can get it started about once every 50 tries for no reason. It has a new starter, distributor, tfi, fuel filter, new gas, pcm, battery, ect, act, ground cable and pos cable, plugs n wires, ign coil. Im getting spark, compression, oil pressure, 40 psi fuel @ the rail, (good ohm-readings on theinjectors). And I've tried different intakes. Right now its a k&n. The timings on. I had it started two nights ago for no particular reason. Let it run for 10 minutes turned it off. And I fired it right back up. This time I went to dial in the timing, even though it was running with no stutter or misfire. So as it was running I started to move the spout and it chugged and I moved the spout wires again and it died. Been diagnosing for 3 months. I'm on my 3rd starter, because I thought the timing was just being tricky. Especially since it fires and turns over but wont catch. The wires look Ok though. And I don't see anything weird around the tfi/ spout/pcm area. But haven't been able to start it again. And there's hardly anything else that I can think of.

 

This is the last time ive had it started.

 

Sounds like you covered almost everything. If it acts up when you pulled on the wires it may be the pick up coil. The module connects to it through the distributor if I remember correctly. Also, if you have a scanner, check for codes or see if you lose communication while this is going on.

 

Next time it's running, move the wiring around the TFI again and see if it quits. If so then you know it's a intermittent connection (or possibly intermittent short) in the harness or nearby components.

 

Wait you already know it's something you can affect, you've done it twice already. Okay so what I would do next is probably let it run while tapping on the TFI and distributor with a screwdriver handle while making sure not to move the harness. If that didn't affect it then I'd pull the harness apart (strip the loom off it) and start looking for damage, loose spices, etc.

 

Thanks guys. Checked for codes. None at all. Tried a new computer.(reman actually). Also the tfi is new. as well as the distributor itself.
I stripped the loom in the corner of the truck where I thought that mightve been the issue, nothing at all was noticeably an issue. Tested for continuity as well in those wires. I pulled the power distribution box and checked the continuity between each fuse. It wants to start but nothing gets it to run. Any other ideas? Been trying everything for months

 

I shoot on the problem.

What parts are Motorcraft and what parts are aftermarket?

Reason is, you need a baseline. I had a similar problem with a JUNK MSD ignition coil.

Just covering some more ground here, do you have spark when it is cranking?
What color is the spark if it exists?
Have you tried with the SPOUT removed?
Are the injectors firing?

Just sorta trying to open the door for more answers to your problem.

 

I like where you're headed timbersteel.
Most of the parts are motorcraft, but I do have the occasional aftermarket. msd cap n rotor also I tried duralast gold. Is aftermarket better or motorcraft?
I do have spark on each cylinder when cranking, but not every cylinder fires every time I crank it. I have a tester and I've tried it without the tester as well. Spark color is bright orange. I've tried with and without the spout removed. I put a noid light on a couple of the injectors. They were firing. I also tested ohms on the injectors by pullingd every single one and compressed them, opened them and Then shot fuel through them. The o-rings were changed , and I primed the fuel pump to watch all of them shoot, after cleaning.
thanks for the response.

 

If you still have your old components and they were good. I'd start to swap them out one by one and see if you have luck. Hopefully it's a component and not in the wiring. ..i hate tracing wires.

 

The only reason I replaced all of those components was to try and get started. Where would I start tracing wires? I've traced grounds, power distribution and a few computer wires. But what do you think?

 

will it run on ether?


when you say "it fires but wont run" what exactly does that mean???


what are your tach readings, if any?

 

When I say it fires I mean it chugs and cranks and each cylinder ignites but it doesn't run.. my tach is aftermarket and small, therefore not precise enough to give a reading at under 1k rpm while cranking. It does seem to crank slow for a new starter.

 

will it run on ether?


so you don't have a factory tach? with good fuel pressure, spark present, it sounds like your PIP is faulty and sending wacky signals, hence the factory tach question.


something also to consider is a faulty EEC...


timing could be way off, you could try advancing it and see if you can get it running while disregarding any timing readings you may have.

 

You said you'd move the harness and it would start missing or die. Maybe a pin is backed out of a connector a little bit, corrosion, maybe one of the pins in a connector overheated and is shorting out. Can't hurt to recheck, doesn't cost anything either, just takes time.

 

Are you using a wiring schematic?