129,000 miles and a 5.8 engine, four mechanics have tried to attack this problem, it goes abit like this. Sometimes it start and runs excellent! Sometimes it will not start but always cranks? When it runs it is flawless...until it just cuts out? When it will not start we put an inline spark tester on and no spark.
We have replaced:
-Distributer (it is the right one I know there is 2 different ones)
-Module: we have tried both black and grey one, it always had a grey one in it so we stuck with it.
-PCM
-Crank sensor
-New ignition swithch and ignition switch and box
- Neutral safety switch (even though it always cranked)
-Cap
-Roter
-Wires
-Plugs
-Coil
So as you can see we threw everything that we could thinkof at this problem..we think. Hence why we are coming to you guys. We have been thinking a bad connector, wire, fuel pump (but we intermitantly loose spark?)
We are at wits end and this is a plow truck that we really need to be reliable this year. If it is a bad connector or wire which do you think it may be? I have referenced this site for a few years now and have always had wonderful luck, please put in your 2 cents, any suggestion would be appresiated!

 

Yes....I think so....check for corrosion at the connectors on the LH side by the master cylinder......

 

Also... have you checked for codes? i bet there are some stored in the computer that might point you in the right direction.

 

I will check the connections next to the master cylinder! Thank You
I have checked the codes, we keep getting a no spark code....I do not remember the exact code but will check in the morning and get back to you guys. The weird thing is since we put all the parts in it, even after it quits we do not get a check engine light like we used to? (not sure if that is a big deal or not) Do you guys know if a cam sensor could do this, not even sure the 5.8 has a crank sensor but we are really grasping for straws here! Thank you very much for your responces!!!

 

At the moment it is now running fine, and no codes are current or stored? Then tonight my father in law drove it 4 miles home and it quit at 35 miles per hour. He cranked it and cranked it, I put an in line spark tester in and surprise no spark again. threw it on the roll back got it to the shop, dropped it in the parking lot and surprise again, started up just fine? I tried all the connections around the master cylinder, cleaned and made sure they were tight, while the truck was running I wiggled every wire and harness in the truck trying to get it to quit but nothing. Even tried the pitch black dark trick to see if I could see anything arching nothing. Does this ring a bell with anybody? We are truely at our witts end.

 

I think i know what's causing your issues... The MLPS might be acting up, try replacing it, the part isn't expensive and the job isn't too complicated.

 

The MLPS shouldn't cause your engine to cut off or keep you from having spark. It doesn't really tie into ignition, at best it ties a bit into timing curves and fuel based on throttle position to help control RPMs when shifting from neutral to drive and similar situations.

Have you tried feeling for hot electrical components after it shuts off? For it to randomly cut off, then start again after sitting, that definitely sounds like heat. Troubleshoot might be as simple as putting your hand on plastic parts to see if any are exceptionally hot.. problem is, it's usually a single wire or circuit that you might not be able to feel through the harness or housing of the part..

If it were my truck, I'd be at the point I would start suspecting stuff you have replaced. There was a guy on here that went through like 4 different distributors, same issue with each one, people kept on him about it being the distributor.. sure enough, eventually he found one that fixed the problem. A lot of the parts sold at these part stores are just flat out junk.

I know it doesn't help you much.. I will say though, distributor, ignition module and coil would still be my main suspects, even though they're new. What brand module, coil and distributor?

just be careful throwing money at new parts.. I'm on my 4th MLPS from Autozone..

It's a 96, 14 years old, it will not hurt at all taking off each plug you can get to, cleaning them, then putting some dialectic grease on and plugging them back in. You might as well, if you don't do it now you'll regret it later anyways.

Even on computerized trucks the ignition system is still pretty basic, it's still coil, module, distributor (uses magnetic pickup for timing still, if this is shot you'll get a no spark) and all the wiring in between them.

Think back, did any of the parts change anything when you replaced them? Make the problem more frequent or different in any way (like the check engine light) ? These stupid intermittent problems are not fun to troubleshoot, you'll think you have it fixed and then BAM, comes back and you're ready to pull your hair out.

 

Errors, thank you for your well thought out reply, the problem still exsist. We have driven it for 5 days now...flawless then tonight it just shut off like someone turned the key off. And again no spark. I have physically chased all of the harnesses however have not checked for warm wires, good thought. As for bad new parts we have been there before also. But where to start? I was thumbing distributed? But maybe you have a better idea. Let me know! thanks again. One common thing does seem that when a more thank typical load is put on it, it seems worse....plowing, towing.

 

Distributor and ICM are suspect. Did you replace both at the same time? How long between replacing and this fail?

 

I agree, distributor (magnetic pickup mainly) and the ICM, maybe even your new PCM.

could be so many things though.. your PCM might be at fault, just read about a guy that got sent the wrong PCM as a replacement and spent months troubleshooting it. I'd also check and recheck the harnesses, trace wiring from your distributor to your ICM (yours is mounted on the fender, right?), then to your PCM. All it takes is one short.

Something worth checking, my plug for my coil broke on me when I took it off and I didn't realize it, sort of a longshot but you should check it. The connectors were being pushed through the plug when I tried to plug it into the coil, I just removed them from the plug to plug each one in individually to make sure they were seated all the way. A lot of my plugs are doing this to me now and I have to make sure every single one of them contacts completely.

Also, check this out: 1983 Ford Bronco TSBs & FSAs (Recalls) for '83-96 Broncos & F150s picture | SuperMotors.net

found it while looking at other stuff and thought about your post, apparently I forgot to post it. I know 96' isn't listed, but trust me when I say some model years can be affected that aren't listed in the TSB.

Replace the dizzy and ICM, you should have warranties on the ones you have? The main problem with the no-spark in the dizzy is the ignition pickup, you can replace that by itself but it's sort of a pain to change.

Also check ignition wiring, that TSB should point out the ones you need to check.. very few things will cause a complete no-spark, even in computer controlled trucks.
Solid State electronics generally are bad off of the assembly line more often than they go bad after they're installed (PCM, ICM).

 

Check (remove and clean) grounds by the battery and where you pull codes on the fenders.

I was have intermittent stalling and no starts then transmission shifting issues. While the PCM was gone for repairs for the transmission issue I pulled my fourth "zone" distributor and installed a Motorcraft stator. One of those fixed the stalling problem and the PCM fixed the shifting problem.