Hot start problems
 

I have an 89 F250 4x4 w/ 460. It starts great when cold, but after driving around and getting up to temp, then parking for a few minutes, sometimes it won't start again. It just cranks and cranks, then I let it rest for 30 seconds and try again. About the 4th or 5th time, it cranks and catches just like it should.

It's turning over fine, and my charging system checked out, so what could it be? TPS? MAF? Starter?

Thanks,
Chris

I would say ECT or IAT sensors.

But you need to see what the self-test says and what is stored in memory.
To read your CM codes or check for other types of codes and to run the self test go to one of these links below:

This is good for the KOEO test:
Ford Fuel Injection How To Run a Self-Test

This one is good for the KOER test:
Ford Fuel Injection KOER Test

Or get a code reader, here is a good one.
The EQUUS #3145
http://i54.photobucket.com/albums/g9...CodeReader.jpg

I ran the KOEO and KOER tests. Here are the codes:

KOEO: 11 - System Pass

CM: 34 - PFE or EVP circuit has intermittently failed above the closed limit of 0.67 volts.

KOER: 11 - System Pass

I've never heard of the PFE or EVP circuits. What does this likely mean?

Thanks,
Chris

It looks like those codes are for the EGR position sensor, so I replaced that, unhooked the battery (I assume this will clear the codes?) and drove around for 20 minutes on the highway and back roads.

I still have the code 34 in CM, and the hot-start problem is still there, although it did start sooner than usual this time. I could be wrong, but it sounded different while cranking this time, and it fired up very strongly as soon as it caught.

Any ideas?

Continuous Memory Code 34 indicates that the EGR valve was open while the engine was stabilized and at idle sometime during vehicle operaion.

Possible causes:

-- EGR valve not seating.

-- EVR solenoid allowing excessive vacuum to EGR valve.

-- Damaged EVP sensor.

I have almost the same problem
 

Except mine still starts but takes a long time, I have only tried the depressing the accelerator tip i was told once or twice I'm not sure if it really helped too much.

Depressing the accelerator will turn off the fuel injectors so no fuel goes into the engine while cranking.
This only helps if you have a flooded engine.

I was told in another thread to do so and see if it helps

Yes if you do this and the engine starts then the engine was flooded and now you can look for a bad injector or fuel pressure regulator.

Are you saying it would be flooded if it started with the accelerator depressed just in his wont start condition? or For my harder/longer starts when hot condition?

I am just saying that is a test for a flooded engine and if it applies to the both of you then yes you have a flooded engine.

Well it starts no matter what it just takes like 3 seconds when hot. Is that bad?

I just replaced the EVP sensor, so I assume it's not that third one.

How would I test the first two causes? Would those cause my failure to start when hot?

A open EGR valve would make it hard to start hot or cold.

The "EVR solenoid allowing excessive vacuum to EGR valve". You could remove the vacuum line from the EGR valve and plug it and see if it goes away but you will set a different code.

If the EGR valve is sticking open when hot it would idle bad before you turned the truck off when the truck is hot.

As I said in my first post most of the time it turns out ti be the ECT or the IAT sensor. They can be bad and not and not give you a code.

It starts just fine when cold, and it always idles great. I'll try replacing the ECT and IAT sensors and see what happens. Thanks for all your help!