I don't think it has anything to do with my mods but I thought I would try here first, so once in a while when I try to start my 97 cherokee it will fire then die and it just keeps doing it till I put my foot on the throttle. But it's really random doesn't seem to happen just when cold or hot just whenever. I was thinking throttle position sensor, any other ideas?

 

fuel pump...get a gauge and check the fuel pressure at the schrader valve. I'm not for sure but I think It should be about 27psi. It has been a few years but mine would be at 11psi at times and would just turn over until I stepped on the pedal. It would also go dead going down the road.

 

I don't have to touch the throttle to get it to fire only to keep it running, I will fire every time but won't stay running unless I hold the throttle down a little

 

These types of posts tend to get common this time of year as the temperature drops and the ambient moisture increases. Although many things can cause a fire/bad idle situation, the first and easiest thing you should be checking is your electrical connections. Particularly, your ground connections. It sounds like your system is suffering from low voltage during startup. The computer will fire, but the low voltage will cause the computer to do some strange things, and continuing to run only when the gas pedal is depressed is one of them.

If you only have to feather the throttle a little to keep it running, then the next thing to check is the throttle body and IAC. Cleaning them, and replacing the IAC if necessary, is a pretty easy and cheap job.

 

Could be.


By putting your foot on the gas pedal you may be moving the TPS off a bad spot on its variable resistor.


Here's some basic tests you can do to your TPS. This does not include a sweep test.


I use a safety pin to back probe.


I've used an analog voltmeter, set to the 5 volt scale, to do a sweep test by probing the OR/DB wire. Found a defect right at the idle stop.



.

 

Mine did this after running the battery dead from sitting too long. I was advised to turn the key to the "ON" position and leave it there for about 10min's without starting it, so the TPS could re-learn its position. Worked like a champ, starts and runs like it should now.

Hope this helps, it's usually the simple stuff that gives me the most problems.

 

Lots of good advice^^^here.
Should also clean your throttle body and IAC,

http://cruiser54.com/?p=60