What was the issue with the PCM? They as a rule don't go bad. I'm just corous thanks.
Craig

 

Craig, I did look at the timing chain using the timing light method (I was being lazy) but I think I'll go back an check it with the rotor... maybe this evening if I can find time to work on it.

The harmonic balancer did cross my mind but it's a little harder to check without pulling it. I've looked at it as well as I can with it on the truck and it looks fine but looks can deceive. I had a Volvo 240 with the B23 engine that was notorious for separating the balancer. That car stranded me in BFE Alabama on a 100 degree day when the balancer came apart and all the accessories stopped working.

Jdan, your symptoms sound a lot like what I have now. The truck has never run correctly since I've owned it. I changed the distributor because when the truck would get hot it would backfire and spit through the throttle body. Cold it would not do that so I though the ICM or PIP could be the culprit. A new distributor (with new ICM and PIP) was only $80 so I thought I'd kill two birds with one stone.

I have a used ECM that a friend gave me that came out of his 1990 Mustang with the 5.0 and a manual transmission that I could at least try, if it would work with my truck.

You guys have given me a few things to look closer at and I'll try too do that today if time allows.

Thanks,
Tony

 

Tony,

I don't think a Mustang computer will work. The Mustangs have HO engines with different perimeters.
Have you researched this website? Fuel Injection Technical Library
It sounds like you need to stop & take a different look at this. I'm afraid you might be going in the wrong direction.

Craig

 

Craig, what direction do you think I need to go?? Are you thinking fuel system instead of ignition?

I guess I'm confused because the truck runs great with the SPOUT off. I mean it has good power, engine smooth, no bucking spitting backfiring or anything.. as a matter of fact I don't know why I don't just run it the way it is. Heck, I didn't give but $800 for the truck and it has a smooth body, nice interior, and drives respectable. It's hard to spend very much money on an $800 truck but I just can't stand not fixing it correctly.

With the SPOUT connected it acts as if the timing is seriously retarded or way out the top. It idles rough and stumbles as it comes off idle but runs pretty well when you get over about 30 and keep the RPMs up. If I allow it to shift and lock the converter it can't pull it's own weight.

It's like the tale of two trucks

Tony

 

This is completely and utterly FALSE for these trucks. There have been dozens of people who have found their computers to be at fault for the various types of issues they've been having over only the few months I've been on these boards. The computers are 20+ years old and have aging components on their boards, the main culprits being the 3 electrolytic can type capacitors which can leak (electricity or electrolyte), can corrode or can rupture. All 4 of those things will cause the computer to not act right. My computer had the bad capacitors and could not properly control the ignition timing at all. Anytime I plugged the spout in the truck went wild and ran horrible. Dumping gas into the engine, timing would jump all over the place. I replaced my computer with one I got from the junkyard and repaired and now my truck runs flawlessly.

OP if you wish to check your computer, pull it out of the firewall and open the case, look for corrosion like you would see on battery terminals around the 3 blue can capacitors. Also look for burn marks in those areas or any broken leads.

 

Thanks for your explanation. I guess living in the desert where it is dry & warm most of the time I don't hear or see many computer issues. But living where you get a lot of moisture or high humidity that would cause corrosion & more electronic issues. The computers are in an area & with Fords known to leak water into the cabs I can see what your saying.
Pulling the computer & looking at it sure wouldn't hurt. It very well could be the answer.

Craig

 

Craig,
That's a really good link that explains the system pretty well. Having worked on a lot of Bosch CSI and Jetronic fuel injection systems (Volkswagen, Volvo, BMW, Audi etc.) I find this information fascinating.

On BMW's, once you clear the adaptations (which is done through the computer and not by pulling the battery cable) you have to start the engine and allow it to die a few times as it relearns the adaptions. Then you allow it to idle for 30 minutes and go drive it for 30 minutes. During this process the engine runs like crap but starts to get better the longer you drive.

I pulled the battery cable when I changed the distributor because it's the safe way to do it and the cable was shot and needed replacing. I'm wondering if I should reconnect the SPOUT, pull the battery cable again, start the truck and allow it to idle for 30 minutes, then go drive it for a while. This would at least allow it time to gather information for the EEC and rebuild the "Adaptive Fuel Table".

It's simple, cheap and may make it run better... it couldn't hurt.

Tony

 

Don't expect to see any major change from clearing the adaptive data on these trucks. There are much fewer sensors and parameters than on your BMW example. There will be nothing vast like you might see on newer cars or trucks when clearing those tables, but it doesn't hurt to clear it out.

 

kjet is stupid. Also I know all about the ****ty crank pulley on the b230's I've had to replace 2 of them. It happens.


Also you should have no issues running the mustang ecu. My maf conversion kit came with the A9L which is from a 5.0HO/manual.

 

I totally agree that the Kjet is stupid. I worked for a Volkswagen Dealer in the late '70s so we worked on a lot of them in Rabbits. The Volvo version worked a little better though.

They tell me the Volvo pulleys came apart due to people using a 3 jaw puller to remove the pulley for timing belt changes. It sounds plausible to me.

It doesn't look like I'll get to work on the truck until weekend due to work related pressures. I'll keep you guys informed as to what I find.

Thanks for all the help,
Tony

 

The Mustang ECU I have is a A9L so I'm going to give that a shot first thing tomorrow.

Tony

 

The mustang A9L will not work , its for a MAF 5.0 , your 90 will be SD.....

 

Well alright then... I don't guess I'll be installing it tomorrow.... anyone want to trade for a A9L EEC?

 

If you have a junkyard local to you go there and look for a truck with similar options to yours. IE. 5.0, manual or auto 4x4 or 2wd whatever your truck is.
The replacement PCM I'm using in my truck is from a '90 and my truck is a '93 but it works great cuz the truck it came out of was a 4.9l manual trans just like my truck.

 

How & where did kjet get into this topic????

I think Tony that the computer option is worth looking into. I would take yours out & open it up & see if you see any corrosion or dull solder joints. See what it looks like inside, you might see a problem right off maybe not. Only if you can get a replacement fairly cheap that will work. Maybe try that. Heck I would think a wrecking yard would trade you I would think the Mustang would be worth more & be more sell-able, maybe not.

Craig