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General Forums => The Mess Hall => Topic started by: DodgeMudder on November 06, 2008, 08:46:52 AM

Title: Jeep wont start warm
Post by: DodgeMudder on November 06, 2008, 08:46:52 AM

Ok, this has been an ongoing problem with my Jeep, that I thought would go away when I did the motor swap and it didn't, anyone know what could be causing this?

When I run my Jeep enough to get it warm, and I shut it off for 8-15 minutes, it won't restart, till I et it sit and cool for 1/2 hour or longer. If I shut it off and restart imediately it starts right back up. With doing the motor swap I've changed out the coil, most of the sensors (I kept the ones on the new motor) plug, wires, fuel injectors, etc.

TIA

Oh yeah, my heep is a '95 YJ 2.5, with a newly swapped in 2.5 outta a '94.

Title: Re: Jeep wont start warm
Post by: neale_rs on November 06, 2008, 09:11:32 AM

Sounds like it could be the fuel pump.

Title: Re: Jeep wont start warm
Post by: Jeffy on November 06, 2008, 12:26:32 PM

Can you hear the fuel pump prime?

Title: Re: Jeep wont start warm
Post by: DodgeMudder on November 07, 2008, 07:42:45 AM

Quote from: Jeffy on November 06, 2008, 12:26:32 PM

Can you hear the fuel pump prime?

Yes I can and it sounds normal.

Does not run an excessive amount of time, does not make any different or more noise than normal.

Title: Re: Jeep wont start warm
Post by: Jeffy on November 07, 2008, 03:02:27 PM

Have you checked your fuel rail pressure?  A guess would be it's not holding pressure when sitting too long.  Although the initial start should take longer as well unless you're letting it build pressure.

Does your fuel system have a return line or is it a TJ system?

Title: Re: Jeep wont start warm
Post by: DodgeMudder on November 09, 2008, 09:11:30 AM

Quote from: Jeffy on November 07, 2008, 03:02:27 PM

Have you checked your fuel rail pressure?  A guess would be it's not holding pressure when sitting too long.  Although the initial start should take longer as well unless you're letting it build pressure.

Does your fuel system have a return line or is it a TJ system?

I don't do anything different on first start up from when it refuse to start.  and it only refuses to start after it's warm then is shut off for 8-15 minutes, if I leave it sit for 20-25 minutes or longer it starts right up w/o any issues.  Same if I start it within 5 minutes of shutting it off.  I've tried cycleing the key on and off a couple times to see if it would help and it doesn't.  I am trying to get a fuel pressure gauge to check the line pressure next time it acts up.

I have a fuel return line.

Title: Re: Jeep wont start warm
Post by: warpedredneck on November 09, 2008, 05:43:17 PM

check for any missing grounds, possibly causing a ign module to overheat,
seen it a few years back at the dealership