4.0L OHV Soul crushed and seeking advice on starting problems

[rubydist]

There is a fair amount of good news in that post, so you are making some good progress!

There are multiple possible reasons for the hot restart difficulties, but one of the first I would suggest checking is the fuel pressure. If the pump is weak or the regulator is bad so the fuel pressure is low, it is easy for the fuel in the engine compartment to vaporize when shut off hot, and that makes it not start until enough new fuel gets pumped up there to have liquid in the fuel rails. I think I would look there first.

 

[TacoBelleGirl]

There is a fair amount of good news in that post, so you are making some good progress!

There are multiple possible reasons for the hot restart difficulties, but one of the first I would suggest checking is the fuel pressure. If the pump is weak or the regulator is bad so the fuel pressure is low, it is easy for the fuel in the engine compartment to vaporize when shut off hot, and that makes it not start until enough new fuel gets pumped up there to have liquid in the fuel rails. I think I would look there first.

Could it vaporize and cause a hot start problem in less than a min of the engine being off? It feels like it's fuel related to me and in the past I have used starting fluid and it does appear to help.
Also the behavior has stuck around after replacing the fuel pump and pressure regulator which makes me think I should have probably taken the time to verify the injectors don't leak and are all happy lol

 

[lil_Blue_Ford]

Depending on how hot the engine and engine bay are and how low the fuel pressure, yes, a hot start problem can show up surprisingly quickly. I had a failing fuel pump in my green Ranger for awhile.

When I put my 5.0 together I did a sort of backyard injector cleaning/testing, the most difficult part was that you needed about 3-4 hands.

That all said, my Choptop now starts better hot than it did, but still is a bit reluctant. I wrapped some insulation around my fuel lines finally on it the other day hoping to fix my problem because it dawned on me that I had never insulated the new fuel lines I put on it because the factory insulation was in poor condition. Like you I have some new stuff on there including a new pump and I just can’t help but wonder what still is the problem.

 

[rubydist]

Injector leak-down can also cause the hot restart issue - as the injector leaks down, the pressure in the rail is reduced, so what is in there can vaporize more easily. However, an injector leak-down issue typically also causes a slow start when cold, as the pump has to push enough fuel up there to fill the rails again. Does it also start late on cold startup?

 

[TacoBelleGirl]

Cold startups have been pretty good, nothing like hot starts.
Typically I turn the key, wait for the fuel pump to prime and shut off, then I crank it over and it fires off right away.

 

[TacoBelleGirl]

never insulated the new fuel lines I put on it because the factory insulation was in poor condition.

There isn't any insulation on mine.. I wonder if they did from the factory back in 91..
Either way I'll get some to put on it.

 

[rubydist]

Cold startups have been pretty good, nothing like hot starts.
Typically I turn the key, wait for the fuel pump to prime and shut off, then I crank it over and it fires off right away.

And if you do that same process on hot restart, it doesn't like to start?

 

[TacoBelleGirl]

And if you do that same process on hot restart, it doesn't like to start?

Correct. I tried to cycle it a couple of times before starting it the other day when it was hot and it still gave me problems

 

[lil_Blue_Ford]

There isn't any insulation on mine.. I wonder if they did from the factory back in 91..
Either way I'll get some to put on it.

I ordered some stuff from McMaster and what came was a roll of fiberglass exhaust wrap. Not exactly what I was expecting and not sure if it’s exactly what I needed. My 88 and 89 had insulation on the fuel lines from the factory but only on the section of the lines that pass near the drivers side exhaust manifold. I can’t remember if my 92 had it or not and that truck currently isn’t here to look at. I figured worst case it wasn’t a bad idea to do something.

I’ve also been wondering about underhood temps in general and I’ve been thinking of experimenting. Need to get my Ranger fixed and my dump truck though so I haven’t really made a priority to do something about that though