Background-- 97 4.0 with 208k on the clock. New timing chain set, crank sensor, fresh tune up.

Problem-- Starts great cold, runs fine. Warms up and has slight miss. Shut it off and it will restart fine if started within about 5 minutes, longer than that and it has to sit for 20ish minutes before it will start again.

Also it pops code 1391 occasionally. I'm leaning towards distributor, but I dropped a new one of those in about 15k ago.


It's driving me crazy- any thoughts, or anyone run across this before?

 

Search heat soak issue ?

 

Not heat soak, it turns over like a champ. I've run small block chevy's for years, so I'm a pro with heat soak. LOL

I should have clarified in the original post- it will turn over and crank just like normal, only it fails to start.

There's the sticker- it runs fine, then simply won't start, and then starts like normal after waiting. Reminds me of vaporlock on a carb....

 

P1391 could mean the Cam Sensor is on its way out. Or the Cam Sensor connector or wiring is damaged/loose.

I wouldn't rule out the ignition coil. Is it the original coil?

 

Yes it is the original coil. I've never had a coil go bad, but then I can't remember running one over 200,000 miles.

May as well change it out this afternoon and give the harness a check while I'm there. I just had my rear defrost eff up from a chaffed wire.

 

That's what heatsoak does - boils the fuel. It doesn't affect cranking.

 

I associate heat soak with cooked starter solenoids. IE small block Chevys.