I got a 1992 F250 5.0 E4OD. I took apart my PCM and noticed a capacitor is broken. It's my guess that this is my problem that I've been having. I had a starting issue only when it was cold out. It ran like it was on 2 cylinders. Once it warmed up it was fine. I checked everything possible and no luck. But now I found my issue! I had the computer in the house for more than 24 hours. I STILL haven't replaced the capacitors since I just discovered this. I took it out and hooked it to my truck and it started right up. So when the computer is warm it's fine but once it's cold it doesn't wanna start. I also kept getting codes 512 and 625. I checked pin #1 and the power to it is great. I guess this capacitor issue could cause that.

Now my question. Does anyone have a diagram or know what exactly these capacitors are doing? I'd like to know for references. The only picture I found was on fordfuelinjection.com but the diagram was much different than this computer. It's strange that I've been driving it like this for months. Like I said, once it warms up, it's great! I'll include a picture below and I circled the capacitors. the RED circled one is the broken one. The others have what looks like battery acid around the prongs. I'd like to know what these are running, especially the broken one.

I'm also trying to figure out if it's really worth replacing the capacitors, I noticed a small burn mark near the broken capacitor. I can't find a cheap computer and I'm unemployed so I gotta be cheap. I found a bag of capacitors (they correct ones too) on ebay for $3. And while I'm at it, does anyone have suggestions on me replacing these? Anything I should know?



This is a picture of the actual PCM. The RED one is the broken one. That's what I'm most concered about.


And Another



Calibration tag

 

These electrolytic capacitors do break down over time.. usually indicated by swelling and/or brown goo seeping out of them, and if left too long they can actually explode. They're not too hard to replace with a soldering iron after you get the epoxy coating off the board, just make sure you replace them with the same value cap(ex: 47uf) that has at least the same voltage rating(higher is OK) and that you observe correct polarity.

 

Would higher voltage make it work better?? And how do I know polarity? Subford sent me a thing on how to replace these but it was for chevy. On their boards it had a + side for the holes. I don't see any on this one. I did notice the black stripe on the capacitors so I don't know if that identifys what side is which for those. The black stripes all face to the right.

 

No.. higher voltage caps won't make it work better but they're safe whereas lower voltage caps are no good at all. Caps are a storage device like a water tank, it can hold any amount of water(voltage) up to it's max rating but no more, so if you have a requirement for 50v caps a 75v will do just fine(assuming it physically fits there), but a 40v cap won't do at all.

Polarity is indicated by the stripe with minus signs on it.. that is negative.