EA82 Hard start when hot.

[DaveT]

Check the coolant temperature sensor. 

[ihscout54]

pretty sure the '88 ECM is not compatible with the '86 harness and components.

[Rust]

Mystery Solved Finally.  When I swapped out the plugs I was only able to change 3, I left the (old) #1 cylinder plug in because it was not coming out easy and I did not want to strip the threads.  This past weekend I finally managed to get it out, after letting it soak in PB Blast for the last few weeks and put in the 4th NGK Plug.   Car started right up, idles great, and re-starts without issues at all.  

 

Bottom line never trust a Subaru motor that is not running NGK Plugs.

 

Never let these clowns into your engine

[Rust]

Well throwing the autolites in the garbage can and running the NGK's has fixed the problem for the last few months.    Unfortunately the hard start when hot problems are back.  It is also idling like crap, almost to the point of stalling when hot.   While waiting for it to cool down to re-start the other day I took the boot off of the TBI and it made it want to start more.  So maybee it is either getting flooded when hot, or not enough air when hot. 

 

If I have time to tinker on it, I'll try swapping out the coolant temp sensor, or the air control valve.

[Rust]

I replaced the coolant temp sensor.  Still hasn't fixed the problem.

 

Here are the current symptoms.

 

Car will re-start when hot from 0-15 min after shut-off.

 

After sitting 15 minutes VERY HARD to re-start.

 

Then have to wait up to 45 min to wait to re-start.

 

I ordered up some new parts for a basic winter tune up.

Air filter, plugs, wires, cap/rotor, and fuel filter. (have good air control valve in my parts stash)

 

Going to replace parts 1 at a time to finally pin down what is causing the problem.  Any folks w/ similar symptoms feel free to chime in. 

[colemanapp]

I had similar problems starting when hot and ended up replacing the distributor, problem solved.

[Rust]

I have several spare dizzys.  Will give it a try.

[robm]

Fuel pump relay under the dash?  They get warm and stop working.  Let them cool off, and away they go again. 

 

Usually, though, it the pump runs the car will.  But it is worth checking.   I had something similar going on, and finally changed the relay,  It seemed to work, but I didn't get a long term chance to test it, as I wrecked the car a few weeks later.

[Rust]

Well have replaced the fuel filter, spark plug wires, and air idle control valve.........still having hard start when hot.

 

The good news it is very predictable.  After shutting the engine off I can re-start it within 0-25 minutes later.  However after 30 minutes of being off, I have to then wait 30-45minutes to re-start.

 

I have some more parts to throw at it, we will see what develops.

 

Is there an easy way to get to the fuel pump relay, and how can it be by-passed?

[Rust]

Well I think the mystery is solved.  The alternator starting lobeing so swapped it out .  Now it re-starts after running no problem.

 

I guess the voltage regulator in the alternator was faulty, and it gave the wrong voltage at start up when hot.