Intermitant start issue

[robertoa1a]

Sometimes my engine wont start on the first try. On the second try it fires right up. I recently replaced the IAC and the EGR and did all of the routine maintenance. Since its an intermitant problem Im having trouble trying to troubleshooting it.

Static fuel pressure seems okay. The fuel pressure regulator looks new. it runs perfect. It drives me crazy thinking about. Could it be a quirky relay, something like a bad gas cap or an alarm cut-off issue. Its a 95 5.0 rwd.:navajo:

 

[IntensiFI]

Is there spark? Does the engine try to turn over? Does it seem like its not getting fuel? Is the start up slow?

I've had intermittent start issues before, first time it was the CAS, second time it was the fuel pump.

 

[Tbars4]

...Duplicate post...
http://www.explorerforum.com/forums/showthread.php?t=237040

 

[eXcali]

I would check your plug wires. when it's running do you hear any miss? You could also try starting it with your gas cap off.

 

[wood1]

I would check your plug wires. when it's running do you hear any miss? You could also try starting it with your gas cap off.

My thoughts exactly. You say you did routine maintenance but what exactly did you do?

My thoughts are, when trying to figure out an issue, you should make sure that all your tune-up parts are new. Plugs, wires, fuel filter, air filter, PCV.

 

[robertoa1a]

Oh yeah! Im a tune-up junky. All new stuff. When I buy a used car I go nuts on it. 2/3 of the time it fires up like a new car so that rules out a lot of things. This one is a real brain teaser. Im waiting for the parts store to open so I can try a new relay and I'll keep ya' posted. At $10 if that isn't it then at least I'll have a spare.

The only reason I brought up the gas cap is when I go for a fill-up I don't get that sucking noise when opening the cap. I might as well replace that too. I heard the cap in itself can be a vacume leak. there is a vacume sensor in the tank. Im thinking that maybe the PCM could get confused if vacume isn't present in the tank.:navajo:

 

[marragtop]

Have you changed the fuel filter?

 

[robertoa1a]

Yes, I did change the filter. It had some junk in it so I have been running some lucas fuel aditive. I think it has some detergent in it to disapate any water that might be in the system and clean injectors.

I just replaced the relays and gas cap but not much change(extreemly long cranking, then on the second try fires up like a champ). Other than that it runs perfect. I heard that there is a check valve in the fuel pump that holds pressure for the next start-up. I dont think thats the cause because I have pressure after its been sitting.

Compression good, new plugs, wires, coils, oil+filter,air filter, fuel filter, Iac, egr, relays, starter spins like a top, idles and runs great, the old plugs showd normal wear with no oil or carbon deposits.

The only thing is that when i changed the oil the first and second time there was a ton of sludge.:navajo:

My 92 was a 4wd and i only needed it once, pulling a large trailer a mile through the woods in a foot of mud in a florida down pour. I was impressed. I looked at the X a difrent way after that.

Now Im ok with my V8 and posi-trac.

 

[marragtop]

When it doesn't start, do you hear the fuel pump prime when you turn the key to the ON position?

 

[robertoa1a]

Yeah, I can hear it prime and the reason this problem is making peoples head hurt is because it doesn't appear to have a pattern. It usually happens when I have a girl in the car or when friends are standing around. I wish I had more info. I think It happens less when its freezing cold out but im in Florida. I'll get my meter out and measure the intake temp sensor. The only other thing that isn't working is the a/c. I don't think that would effect start-up.:navajo:

If the fuel pump is just a little week on start then I don't think It would warent going through the trouble replacing it till it gets worse. The pressure is within specs so I was hoping it is something I overlooked.