A friend gave me a 1975 2WD F250 last summer that had been parked in his driveway and not started for about 8 years. I've been going through the components cleaning, servicing, updating, upgrading until I've single handedly solved the economic crisis for my local parts house.

It has been a lot of fun and enjoyment though there has also been frustration and head scratching at times.

This truck had the emissions gear removed at some time for the most part. It still had the OEM Holley 4 barrel carb. I tinkered with it, replaced old gaskets, patched the pitted intake manifold with over the counter products to stop the base plate vaccum leaks, regular fuel additives to clean and dewater the fuel that had been in the tank for so long, installed extra fuel filters and changed them often, etc.

I was trying to avoid dropping the fuel tank for cleaning or replacing but every time I got it running nicely for a few weeks it would have another fuel related problem.

I finally decided to attack the problem. The old Holley was shot so I bought a new 600 CFM Holley 4160, similar carb and recommended replacement by a guy at Holley. I bought and installed a new gas tank.

Went to start it up and the starter went out...my part house is enjoying this.

New starter, new Holley with an electric choke, new tank, new gas, new filter and all rubber sections of the fuel lines replaced. New fuel pump is on my work bench and will change soon but nobody seems to think I really need to replace it

It starts and runs beautiful. Now here is the problem I hope your experience can help me troubleshoot...

I start the truck and drive 20-30 miles wihout a hiccup. After driving that distance, or sooner if I get into stop and go traffic, it starts running like crap...won't hold an idle...dies every time I stop...gets harder to start every time it dies...when I get it started it dies when putting it in gear unless I hold the idle high to get going and then it runs like it is flooded while getting speed up. Once cruising it runs and accelerates fine but will have brief episodes like it can't get any fuel.

I limp home and after it cools down it starts great and runs beautiful for about 20 minutes...deja vu all over again.

Any ideas?

 

I have had this problem several times and as far as I can tell, (could be wrong) it seemed to me that there was crap built up in the metal fuel lines, I never really did anything besides blowing the fuel lines out backwards with air pressure, and just driving it helps clear them

 

So, it does have electronic ignition ?

 

yes it does have electronic ignition

 

Those symptoms lead me to believe your ignition control module is on its way out, they over heat and shut down, cool off awhile then function again, until eventually they just give out completely.

 

Agree with Highboy. Could be your EI unit. Sometimes overheating will be shown by the epoxy on the underside of it melting and dripping. Any sign of that?

 

SOP for the duraspark module is to put spacers between it and the fender to increase airflow. They are known to overheat

 

I've been going to reply with thanks since you answered my question six weeks ago.

You were so right about the ignition control module. I also needed a new stator so I ended up replacing the control module, distributor and coil and all of the related problems were solved.

You might get a kick out of this story. I bought the control module the next day after your post. Installed it and headed to work the next morning. It started and ran great. I live in a small town east of Seattle and drive 20 mles north to work. About 7 miles on the route to work is my local parts house. As I passed the parts house the truck started to act up like before but not as severe. I remembered reading that if you buy a Chinese made control module don't be suprised if it only lasts about 10 miles out of the box. I stopped at the parts house on my way home after work to make sure I had the best module. It was made in the US but they exchanged it for me anyway to be sure. Test drive showed it still had a problem. We decided it might need a stator also and since the distributor looked like the original I had them order a new one which would of course come with a new stator and be in stock the next morning. Leaving the parts house about 7 PM the truck died in front of a sports bar. It wouldn't start so I coasted into the bank parking lot next door. While checking the old distributor to see if I could find anyting amiss the distributor moved and screwed up my timing. I just guessed where it was before and tried to start it. I was way off. The truck backfired so loud it sounded like a deer rifle. As I got out of my truck the sports bar emptied when about 50 people ran out to see who had been shot in the parking lot. They all had a good laugh when I yelled it was just my timing slipped. Five minutes later the cops arrived. I asked the cop running past my truck if he was responding to shots fired. He said, "Yeah...did you hear it?" I told him everything. He told me to get a ride home and he would keep an eye on my truck for the night. Next day a mechanic friend met me there...installed the new distributor and coil...it's running great ever since.

Thanks again for the advice.

rickpwjr