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

 

[TacoBelleGirl]

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

For the insulation I am looking at getting probably something like this. Looks like a pretty nice solution.
I too have been wondering about the under-hood temps. I feel like mine have always been pretty warm.
Not sure if this is something the off-the-counter controllers can do, but perhaps leaving the fan on for a min or so after the engine shuts off would be good to help bring down that temp.

 

[lil_Blue_Ford]

For the insulation I am looking at getting probably something like this. Looks like a pretty nice solution.
I too have been wondering about the under-hood temps. I feel like mine have always been pretty warm.
Not sure if this is something the off-the-counter controllers can do, but perhaps leaving the fan on for a min or so after the engine shuts off would be good to help bring down that temp.

For insulation, that looks a lot like factory type stuff, and what I thought I was getting from McMaster since they’re a hardware supplier not an auto parts dealer. I may have to put that on my list.

I confess I never have a whole lot of thought to under hood temps until I was watching some off road recovery stuff and those guys are talking about the common XJ problem with the 4.0 and having heat problems in the engine bay that usually results in either spacers at the hinges or putting holes in your hood to help control it. Couple in my hot start problems and here we are.

I haven’t replaced my regulator yet but the last I checked it seemed to be working fine. I can’t remember if I tested the injectors the last time I replaced a motor. But it’s all new fuel system. Tank, pump, lines, filter. Even with the insulation I was able to put on the fuel lines and leaving my electric fan run until the motor completely cools down it’s still got a little hesitation to start hot. Makes one continue to question if I’m looking at all the possibilities.

I’m not sure if there’s an aftermarket controller or not, haven’t gone looking. It would be relatively easy to make something if not. I just have my electric fan wired to the poor boy controller. I have an on-off-on toggle with an indicator light to control the fan relay. Temperature sensor is wired to one side of the switch and a constant hot on the other. So the fan can be on, off, or controlled entirely by the temperature sensor. I’ve found that the fan I currently have doesn’t draw down the battery just leaving it in the position where the temperature sensor turns the fan on and off all the time. So when I shut the truck off and walk away the fan runs until the motor is cool. Not an ideal solution, but I’m reluctant to do otherwise until I can get a better hand on this hot start reluctance.

 

[TacoBelleGirl]

For insulation, that looks a lot like factory type stuff, and what I thought I was getting from McMaster since they’re a hardware supplier not an auto parts dealer. I may have to put that on my list.

I confess I never have a whole lot of thought to under hood temps until I was watching some off road recovery stuff and those guys are talking about the common XJ problem with the 4.0 and having heat problems in the engine bay that usually results in either spacers at the hinges or putting holes in your hood to help control it. Couple in my hot start problems and here we are.

I haven’t replaced my regulator yet but the last I checked it seemed to be working fine. I can’t remember if I tested the injectors the last time I replaced a motor. But it’s all new fuel system. Tank, pump, lines, filter. Even with the insulation I was able to put on the fuel lines and leaving my electric fan run until the motor completely cools down it’s still got a little hesitation to start hot. Makes one continue to question if I’m looking at all the possibilities.

I’m not sure if there’s an aftermarket controller or not, haven’t gone looking. It would be relatively easy to make something if not. I just have my electric fan wired to the poor boy controller. I have an on-off-on toggle with an indicator light to control the fan relay. Temperature sensor is wired to one side of the switch and a constant hot on the other. So the fan can be on, off, or controlled entirely by the temperature sensor. I’ve found that the fan I currently have doesn’t draw down the battery just leaving it in the position where the temperature sensor turns the fan on and off all the time. So when I shut the truck off and walk away the fan runs until the motor is cool. Not an ideal solution, but I’m reluctant to do otherwise until I can get a better hand on this hot start reluctance.

I ordered that so I will share my thoughts once it's here and I've had the chance to put it on the fuel lines.

I now have the control side 12v for my fan relay switched by tapping into the instrument cluster fuse and the ground is switched via the thermostat I installed on the upper hose..
So it'll only run with key in and on accessory or run.
I also have a new regulator, pump, and filter though not the lines.

Made the cover still fit lol

 

[Li'l Work Truck]

...when I shut the truck off and walk away the fan runs until the motor is cool. Not an ideal solution, but I’m reluctant to do otherwise until I can get a better hand on this hot start reluctance.

That was fairly common in '80's turbo cars, and my wife's Fiat even does that, so it was an OEM solution at one time.

 

[lil_Blue_Ford]

I ordered that so I will share my thoughts once it's here and I've had the chance to put it on the fuel lines.

I now have the control side 12v for my fan relay switched by tapping into the instrument cluster fuse and the ground is switched via the thermostat I installed on the upper hose..
So it'll only run with key in and on accessory or run.
I also have a new regulator, pump, and filter though not the lines.

Made the cover still fit lol
View attachment 147999

Yeah, that works. I have an accessory fuse block in the Choptop so I just picked up power there. My trucks always end up with accessory fuse panels sooner or later, lol.

 

[lil_Blue_Ford]

That was fairly common in '80's turbo cars, and my wife's Fiat even does that, so it was an OEM solution at one time.

Interesting