My 1985 Dodge D150, with a 1979 318 engine, won't start after getting to operating temperature. It's suppose to have a three way fuel filter on it,
but someone before me put on a regular inline fuel filter and then plugged off the third line. I'm thinking it could be vapor locking. I was also thinking
it could be the distributor pickup coil. Does anyone have any suggestions? Also, anyone have any idea where the EGR valve is supposed to plug
into? Whoever had this truck before me, really did a number on it. I been working on it for nearly 2 years now, and I almost got it. I just need to
figure out why it won't start after getting to operating temperature. Any suggestions will be greatly appreciated.

Thea

 

Find out what's missing when it won't start. If you are getting spark, then you are either getting too much, or not enough fuel.

Carbed? Is the choke staying shut??

 

Does it still have the lean burn system on it? If so it has two pick up coils in the distributor. A pic of the engine compartment would answer a lot of questions what you have or don't.

 

I have no idea what could be missing. A friend of mine said that the purge can is gone. Also, the EGR valve isn't hooked up and I don't know where it's supposed to go on the carb. It is carbed, but it's not the original manufacturer carb application. There are all these plastic vacuum lines, which is supposed to be hooked up to the carb but they are all broken. However, since it's an older engine, I don't see how those plastic lines would make any difference. When I was a kid back in the 80s, my mom had a 79 Dodge Tradesman Van and it didn't have all those plastic lines on it. I didn't think to check if the choke is staying shut. I tried to add photos but they won't upload.

 

Engine needs three things to run, fuel, spark, and air. You are missing at least one. See which one it is.

 

Yes, I understand an engine needs fuel, spark, and air in order to run. However, I can go out and start my truck right now, just as long as it's cold.
Why would it have fuel, spark, and air when it's cold, but not when it's at operating temp? That just doesn't make sense, so there has to be something
else that's preventing it from starting when at operating temp. I've changed the coil, rebuilt the carb, did a tune up, put on a new fuel filter and replaced
the thermostat. A couple of people from around my town mention the pickup coil. Could the pickup coil in the distributor be the problem?

 

Some variety of electronic ignition? Something is getting hot, and failing. You can bet your bottom dollar that's an electrical part. Not sure what all your ignition system involves though..... If there is a smartbox on the firewall for it, that would be a suspect as well.

 

i would guess it is likely a fuel related issue. which carb is on it? i don't know if you have access to it but might be worth trying ethanol free gas if it is available locally. will it start if you pump the gas after cranking it for a few seconds?
https://www.pure-gas.org/station/7252

 

After it won't start check to see if you have spark. No spark then you know it's in the ignition system. If it has spark spray some stating fluid into the carb and see if it starts. If so then it's in the fuel system. And check the choke to see if it's sticking and not opening all the way after it's hot.

 

Thinkin' maybe vapor lock?