This is about a 91 bronco with the 5.8 and auto trans it was my buddies that many people tried to troubleshoot including myslef due to irractic idle, running rich(black smoke from exhaust), poor gas mileage about 9 mpg, all the basic stuff was done new plugs, wires, dist cap and rotor. along comes where i started had him change fuel filter it was and original belive it or not, i changed fpr (fuel pressure regulator) it seemed to help but only for a few days.
NOW FOR THE SYMTOMS
1. would start fine when cold and ran good cold as soon as it warmed up it would puff black smoke and run like crap.
1A. solution i said the ect, so i got my mutilmeter out and read it cold and warm all within specsas per haynes manual
2. so maybe the tps
2A. tps read out good as per haynes manual
3. was thinking plugged cat but ran fine when cold
to make this simple were read every sensor on engine that the haynes manual would allow and all checked again within specs as per haynes manual

so i though maybe injectors were stuck open but wouldnt they be stuck open when engine is cold too...???

so he sold me the bronco he started it up to come to my house made it 2miles and it died and wouldnt start so he had it towed. so i finally had time to tinker with it abit and tried to start but nothing then i noticed that the fuel pump was staying running with the key on engine off not timing out like its suppose to, i thought well thats wierd, instead of throwing a couple 15 dollar relays i pulled the eec, and found it to have water and the capacitors leaking a bit as shown in pictures below , before i jump and i know i didnt pull the codes anything else i should look at

 

It doesn't look good. From the looks of the caps, you can replace them if you have time and some soldering experience. I would try the jy's and find a donor if possible. If not, try eBay, and lastly, the parts house. Look for an EEC code at the grey pin connector where the harness plugs in.

Here's the link, http://oldfuelinjection.com/?p=17

 

I just went through this with my f150. the round capacitor things were actually burnt at the solder points and they were leaking on top of that. I was getting a very rough and wondering idle once hot, engine light with no codes, bucking, hesitating, random ignition cuts, and running very rich at random. I think the computer is supposed to throw a 700 or such code when it's shot but don't quote mine on that because mine never gave any codes. I have a loner in the truck right now until my maf conversion and new computer come and it runs like it should.

 

The problem with using a junkyard replacement is that it likely also has failing capacitors. So far, all the ones I've pulled at the junkyard have evidence of leaking capacitors.

Best bet is to either replace the capacitors yourself or get a truly rebuilt unit (and check to make sure the capacitors were actually replaced).

 

True about the jy... I'd pull it, then remove the casing while there to check. $25 versus $75-200 from either eBay or a parts store. I pulled 2 from the jy and both appeared to be ok "cap" wise. Then again, total cost of caps and solder, maybe $25, maybe even less.

 

Yep. In fact, I bought extras of the correct caps, so if someone wants a set or two for something less than $25, just drop me a PM.

 

New news, i went to talk to several ford technicians and they told me as long as the 89-91 ford 5.0 has a MAF it will run a 5.8 and it does reason i asked was every 5.8 ford pickup and bronco had the computer already taken at 3 different junkyards. The one i bought looks brand new, I know I was leary with the codes on the ecm and all the parts stores telling me it will not work. I also made sure the F150 I pulled it from was a overdrive trans i have yet to check that but at least it will drive down the road the max speed where i live is 50mph (Island in washington). it had plenty of power no more pure fuel dripping from exhaust and crazy idle i left it running for 1 hour just to be sure i didnt get my hopes up. now if it starts perfect in the morning then i will as happy as a pig in mud.

thanks guys

 

Good to hear that it's running better and keeps running well for you. I was curious how your dilemma was solved. Thanks for posting an update as so is everyone else here.