No. Although I have tried a tank and well as adding a course of techron and that does not seem to help.

Should I only run hi-test?

 

I am willing to bet it is not the coils, since they may do it as a high heat issue but it would smooth out if you have been driving it and it was a heat issue. If you do need coils I have some that would be far less money.

You need to start looking at something else for why it is doing it. I am still willing to bet it is related to O2 sensors, they will not always set off a code. When was the last time they were replaced?

 

I checked with my mechanic today and he did, indeed, NOT clean the MAF.
So I guess I still have that to eliminate. I will try to do it myself if there are detailed instructions somewhere. I know I have to take it out and spray MAF cleaner and let it air dry. I start to get lame in the process where the how to take it out part starts.

All help appreciated, as always.

As long as I am going for it I guess I need changing O2 sensor training also.
I have an idea the MAF job is not that difficult, I hope the O2 sensor falls into the same realm.

 

MAF job is pretty easy. I think if it needed oxygen sensors, it would throw a code. Yes, you should be running premium especially in hot weather. It prevents detonation which sounds a lot like the problem you are having.

 

Hello,I would check the fuel temperature sensor on the fuel rail it might cause the computer to decrease the fuel pressure or increase it under hot engine operations it might be defective.

 

1995 RR 4.0 SE still having problems with warm starts. New plugs, wires, removed and cleaned MAF. Running premium fuel. PERFECT from a cold start, even to drive highway for 1 hour without stopping. Park it for 5 minutes and starting is difficult with detonation sounds until engine is coaxed into taking gas. As long as I am running with out starts and stops truck is fine. Engine temp goes past half way when at traffic light, backs down when I turn of AC compressor. When I installed the new battery I accidentially knocked off the small overflow hose from side of cap to reservoir. slight leak at hose next to cap. Anything I can do to seal it without having to replace entire radiator? My mech says no. He also wants to replace the coils, he thinks my problems are caused by bad coils. Is it a hard job? Where can I buy coils for truck? Please, anyone, provide solutions or magic! Should I also consider replacing O2 sensors as someone suggested? How about the fuel temp sensor? Don't get me wrong I love the truck!

 

If it running for an hour and not having a problem then it is not related to the 02 Sensors like I thought it would be.

If you need some coils I have a set if you want to try. I would even make you a deal, if you pay for shipping I will send them to you to see is that is the problem. If it fixes it then you can pay me for them. If it does not then just send them or yours back and keep looking.

I would still think that if the coils would be the issue with heat then it would do it all the time and not just on a restart. I am not sure where to go from here.

 

Sounds fuel related to me. You may be getting some vapor lock from a hot fuel line (gas boils) after shut down and it sits for a bit. Once it cools off then it works fine eh?

You can test the fuel pressure at the rail schrader valve - you'll need a proper fuel pressure tester. Also I'd check the sensor that gilboulou13 referenced. I don't have RAVE on me but there is probably a check for that in there.

If that doesn't work then perhaps take Rob up on his very generous offer regarding the coils (nice job Rob).