rough engine run when warm!

[Buckshot_1]

When starting my explorer after it has been running, leave it for about 20mins, starting it it has hard time strating and when it does it runs rough. When it is cold no problems at all. Now the rough doesn't last long and it does it once in awhile. Any ideas??? Was told it is that engine's nature to do that at Ford. Anyone else have the same problem?

 

[Opera House]

Fuel leakdown

That problem is often associated with a leaking fuel pressure regulator or injector. When you turn the key on, the fuel pump will only come on for 3 seconds till the engine starts. this is not long enough to get rid of the bubble.

You can put a pressure gauge on the fuel rail tap and monitor the pressure. Turn key (not start) and read pressure. It should hold better than 20# for 30 minutes.

When the engine is hot and you stop for 30 minutes, the fuel vaporizes. This is because there is not enough pressure to keep it from boiling.

You can try and chase this down by buying a new regulator. Some put in a push button that bypasses the fuel relay. They press this before they start cranking to flush the system. These little leaks don't bother a running engine because the fuel system is high bypass when running. If Ford would have made it 10 seconds instead of three, you wouldn't have this problem.

 

[espnfreak]

i have this problem too, so a new fpr is the way to fix it?

 

[glfredrick]

Opera House,
This is an unrelated question, but perhaps you could PM me with an answer about my 5R55E. I just did a total overhaul after a failed front planetary set (fried it, along with the front band) and also did a replacement of the plate, valve body gaskets, epc solenoid and all the clutches and seals inside - all clutches air test OK. I also did a trans-go shift kit while I was in there to eliminate some of the issues with the shift patterns on this trans.

Before the rebuild, I had no drive or reverse, after the rebuild, I still have no drive or reverse. Any ideas before I go nuts and shoot that thing?

Thanks...

 

[Buckshot_1]

So a new regulator might work for this? My explorer has almost 340,000km on it, maybe a set of injectors too??