intermittent problems with hot start

[newt]

I have a 95 XLT that has a problem with intermittent problems with hot starting, usually also during warm weather, maybe once every two to three months. The engine will turn over well. If I wait about 1/2 hour and let it cool down, the engine will start normally. The fuel sensor was changed about one year ago and did not seem to solve the problem.
Thanks, Newt from Florida

 

[marragtop]

When it won't start, do you hear the fuel pump prime for a second or two? If not, replace the fuel pump relay. Easy and cheap fix.

 

[tweber]

Did you try this fix? I have the same problem with my 97 Explorer. It's at the dealer right now and they can't find anything wrong with it.

 

[Turdle]

I agree the first step is to eliminate the fuel pump relay as the cause. Swap it with another relay. Since the problem is intermittent, it could take a day or 2 to make sure the problem is gone or not.
If this fixes your problem, replace the swapped relay or you'll induce another problem.

 

[wjsullivan]

So did the fuel pump relay fix the issue?

My 97 has randomly not started 7 times in the last year but did start about 15-30 minutes later. The mechanic can't find any indications and I get no lights.

 

[leopaul30]

Read this post:

http://www.explorerforum.com/forums/showthread.php?t=133987&highlight=hot+start

 

[Papa]

Try checking the fuel pressure especially when it will not start. This will help validate your testing and repairs of the fuel electrical circuit so you can virtually see what your are doing.

 

[always been ford]

starting problems when hot

There is a lot of good information here. I appreciate all the help.
I am having a similar problem with a 2001 Sport Trac. Only about 22k miles and it will not start somedays after I have driven it for a while. It can be a hot day or a moderate day tempature wise. I will drive to a location and shut it off. When I get back it acts like it is flooded. Turns over fine. I read about the IAC and took it out and was clean as new.
Last time it didn't start had the chance to pour water over the radiator and front of the engine to try to cool it down, thinking the temp might be the issue. No help. It seems that time is the only cure. I will wait from 30 minutes to an hour and then it will start normal. Now it does seem to have a low idle normally. About 600 on the tach, but have not checked it with a meter.

When it happens next I will try swapping the relay. Any other ideas? Thank you. Oh, the truck is completely stock.

 

[wjsullivan]

My problem was eventually solved. The fuel pump finally died. Once replaced everything was fine.

 

[javey]

What does it do? Could be the thermostat, which doesn't let coolant flow through the engine until ithe coolant is up to operating temp, causing engine malfunctions.

 

[always been ford]

A little follow up

I might suspect it was a thermostat, but it comes to temperature and runs and starts fine on many occasions it is just when I run it for a longer trip. A longer trip may be 25 miles. But even then it only hasn't started 5 times in the last 4 months. And I did try cooling down the engine with water when it wouldn't start last time and didn't seem to help. Still had to wait 45 minutes.

When running everything seems to be fine. Doesn't hesitate when hitting the gas. And I can be going 20 MPH or 70 MPH and accelerate fine. So I didn't suspect fuel pump. Hate to change it without knowing a little more.