Jeep Comanche needs a little gas when cold

Hello, another thread for my 1989 Jeep Comanche. 2.5l. It's not a big problem, and it's had it as long as I've had the truck. It runs beautifully, but on a cold start, it'll fire up, then try to stay running, but the idle slowly drops and dies in about 5 seconds... It'll start up and idle up then down as it should the second time I start it... But when it's cold, if I press on the gas when I start it, even if it's very very lightly pressing on it, it'll fire up beautifully, then I can let off of the gas the very second it starts up and it doesn't die. Like I said, it's a very minor issue, because it's not much of an issue at all... But I would like it fixed. Maybe fuel filter? Recently plugs wires cap and rotor were changed, so not that. Any ideas would be greatly appreciated, thanks.

 

I believe there were some other posts with similar issue.

 

Oh, okay, could you direct me toward them? I don't know how to find them.

 

Actually those were your older posts I was thinking of. I assume it is doing something different now. I don't know for your year, but are you fuel injected or carbureted? Just a guess, but I am thinking that the 4cyl in 89 was fuel injected. If so, fuel injection systems stay pressurized after the motor shuts down. My thoughts are that you may possibly be losing a little pressure and that first crank you are purging the air out of the system and reaching fresh fuel. Check all of your fuel lines for cracks, and could be that the injectors are leaking. If it is not causing any issues other than a 2 crank start-up it wouldn't be worth getting new injectors to me.

 

Thanks for the reply! It's tbi... Single injector. Could fuel lines still be the problem since it starts right up the first time if I tap the gas when I start it?

 

Some systems work different. I think the older systems like in your jeep increase the fuel dump when you hit the gas pedal. Some newer systems when you crank the motor bypass the tps and will only give a set amount of fuel when starting. It really does sound like you are losing pressure and I would guess it is more from the injector. Losing pressure is losing pressure whether or not it is from the injector or rubber sections of the fuel line or at the joints where clamps are necessary.

 

My money is on the injector too, especially what I'm about to tell you will sell you on the injector too... I had taken the injector out awhile ago to clean things up, but temporarily put it back together with the same o rings, and you're not supposed to reuse the old ones, so that's probably it.