Dulciusexasperis

So my father sold me his 1987 F-150 4.9 EFI 4x4 manual trans. He tells me to get a battery... He's pretty sure the one in the truck is dead. I go to pick it up today and after replacing the battery... we start it up and it runs fine for about 15 minutes, then it suddenly shuts off. Not a slowly stalling out but like someone had turned the key off. it just quits. You go to start the truck.... it turns over just fine but it will not catch and start up. So when turning the key on the 2 low pressure fuel pumps in the tank hum. the high pressure pump on the frame hums. We're pretty sure its not a fuel problem. Took the distributor cap off. It rotates as it should and it is not loose. Check the fuses all are ok. When you turn the key on the relays click. Now I remove the Number 1 cylinder spark plug wire while my dad is turning it over to see if there is spark. Suddenly it fires back up... I reinstall the wire. Truck runs for a good 5 Minutes and same thing it just shuts off again. I feel the ICM and its pretty warm I'm aware those tend to be heat sensitive. I Bought a new one threw it on thinking that was the problem and same thing it cranks but no start... Now I run a test light to the negative post on the coil. Turn the key on I get a good bright light. Turn it over the light should pulse, it does not, it stays on. Any Ideas on what could cause this? On the positive post on the coil I'm getting battery voltage which is good. So what am I missing. I have to be overlooking or over thinking this whole thing. Has anyone had a problem similar to this? Any feed back I can get would be amazing. Thanks guys.

memoniz

Try to determine if it is fuel or fire that is the problem for sure. Spray some starter fluid in and if it fires it's fuel, if it doesn't it's spark. Forge-World-Ford posted a site for someone else on the main page of this section for easy engine diagnosis. Take a look at that. In my experiences, I would look towards the PIP sensor if it's EEC-IV. Don't remember what an '87 has for ignition. If it's fuel, well, I haven't had any of those problems yet, maybe someone else could help. The Haynes manual has a pretty good diagnostic section also.

It's under "'96 5.0 stops cold, won't fire" posted by Chris_1

Dulciusexasperis

Thanks man. We tried using starting fluid and couldn't get it to start up.

Dulciusexasperis

The more things I read on it the more I'm thinking it's the PIP Sensor.

Forge-World-FORD

He means this
http://easyautodiagnostics.com/ford_...d_module_1.php

Not sure how much of it applies to your year as far as specific parts but its a good starting place.

Dulciusexasperis

Yea I read through there earlier as far as the ignition system goes it is about identical just my icm is mounted on the distributor rather than the firewall. Now if I do find that it is the pip sensor. Would tear the distributor apart to replace it or go ahead and just change the distributer?

Forge-World-FORD

That really depends on what you want. Either way the distributor has to come out. To replace the pip you pretty much have to tear down the whole distributor. Its a cost vs time/experience situation. Is the extra work worth the lower cost/ or does less work justify the higher cost? Make sure that is it though. First time I had starting issues I went through the troubleshooting steps three times with no conclusive outcome. Fourth time I tested and found my coil was having intermittent issues before it failed completely.

Dulciusexasperis

I completely agree. I'm going through steps again tomorrow just to double check. Will let you guys know what I find. Appreciate thr help that link you sent really helped a lot.

Forge-World-FORD

That's what we're here for.

Dulciusexasperis

Alrighty then. So after testing the ignition coil 4 or 5 times and every test giving it a green light. I started testing the pip and it failed. So I go to pick up a new one, remove the distributer... tear it down. Install the new sensor put the distributor all back together.... put in the truck and........ VROOM started right up...... for 2 mins until it did the exact same thing. just Fu**ing cranks. This time however a little red engine light comes on. Suh-weet get out the obd I scanner. Its tells me it has a continuous memory 18 code. Which is a No Spout Signal/ Tach... WTF is that??? Looked up how to test it seems straight forward. But to fix it what am I looking for? a bad PCM? a bad wire? a bad ground? Any ideas or anything like this come up with your truck. This is starting to get irritating SOB ran fine 3 months ago my dad signs the title to me and all hell breaks loose. Any kinda feedback or ideas would be great guys. If you'll excuse me Im gonna drink heavily while I do my own research.