92 F150 cranks but won't start
 

Hey,

So I have a 92 F150. 228k miles. On January 27th on our way home, the harmonic balancer busted. We got that fixed and everything was good for 2 days, and then my truck very quickly went downhill. It started by not getting any power when driving at any point. It bogged down and I would have to have pedal to the floor to go 25 mph. It finally just quit moving even with pedal to the floor. We parked it, and then it wouldn't start. Sometimes it would, but it would die immediately. We thought, oh yeah it's the fuel pump. So we changed that. Truck still won't start. We got it started with starter fluid, so we decided to change the throttle position sensor. No change. My husband was able to start it with the pedal to the floor and keep it running, but as soon as he took his foot off the gas it died. We checked the timing and it's fine. It has spark. The battery is fully charged. It has fresh fuel. He checked the fuses and they're all good.

Any ideas would be extremely helpful because we are moving in about a month and we really need to get it fixed.

Thank ya'll!

with the engine fully warmed up, pull codes .
also, test fuel pressure with a gauge.

fuel pressure regulator possibly. as its getting fuel but seemingly not enough. you might think about running some seafoam through it to clean out the fuel system. also might wanna change out the fuel filter.

just some thoughts, hope it helps.

Fuel pressure is 45 after changing the fuel pump out. We changed the fuel pressure regulator and the fuel filter first thing. We regularly use seafoam. Only codes we could get was the 111 and 512

Continuous Memory DTC 512 indicates the PCM has experienced a power interrupt in its Keep Alive Memory (KAM) circuit.

NOTE:
If KAPWR is interrupted to the PCM, for example when battery is disconnected, DTC 512 may be stored in Continuous Memory.

If you have not disconnected the battery then you may have a bad PCM Computer or bad wiring to pin #1 of the PCM.

Is there a way to test the wiring to the pin? Or test the PCM? Or do you just have to change it and find out? We've never messed with the computer before, so this is all new.

Pin #1 in the PCM plug should have power (battery voltage) to it at all times.
You could unplug the plug and test for power at pin #1 while shaking the wiring harness.
Or while it is unplugged remove the pos battery post and check for continuity between the pos battery cable and pin #1 of the PCM plug.

Diagram below shows pin #1 position.
http://i54.photobucket.com/albums/g9...pshjwpmrzo.jpg

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Alright great, thanks! We'll check it out later after work

Okay. Pin #1 has voltage to it. We opened up the PCM, and noticed quite a bit of corrosion on it. Would this cause my problems?https://cimg7.ibsrv.net/gimg/www.for...34df234413.jpghttps://cimg8.ibsrv.net/gimg/www.for...6c40a0e053.jpghttps://cimg9.ibsrv.net/gimg/www.for...7b4eb7790c.jpghttps://cimg1.ibsrv.net/gimg/www.for...2918e0486c.jpg

yeah. Those capacitors are bad, have leaked all their magic onto the board.
Google "replace capacitors", watch a couple of youtube videos. It's easy, but not a guarantee the board's not ****ed.

Yeah, those capacitors are shot.

The bad thing is that you have don't know how badly corroded it may be beyond the surface coating. My last PCM failed and the Capacitors leaked all the electrolyte fluid out, which in turned destroyed the traces on the surface.

You would have to remove the damaged capacitors, throughly scrape the protective coating over and see how badly damaged the underlayer is.

1. You can try to replace them yourself
2. Find a TV, Electronics repair shop that can replace the capacitors and Repair the surface trace IF needed.
3. Go to the auto part store and see if they have one readily available.

I list #3 as a last resort. You will have a warranty with it, but you don't know​ any history from it or how it was repaired.

Hopefully the corrosive fluid didn't​ eat through.

It also looks like that PCM was repaired before as one of the caps is stick up far from the board and that is not how they are made.

We'll get it fixed then. What do ya'll reckon the odds are that it's just this causing all my issues and not that plus something else like the fuel injectors? I've been without my truck since january due to the harmonic balancer busting and then now this. We are moving in May and we really need it to be running D:

The odds are a replacement PCM will fix your problem.
Not saying you might have other items but you need to get the PCM problem solved first.

I sure hope there is nothing else haha this has been a real fiasco. We'll get the PCM taken care of. I'll let ya'll know what happens after that! Thanks so much!