'93 Jeep 4.0L misses in gear - fuel issue?

bowtieman55

bowtieman55

Well-Known Member
Joined
Jan 25, 2006
Location
Edenton, NC
The '93 has roughly 230,000 miles on it. Recently, I was driving down the road and as I came to stop, it started idling rough like it was going to cut off. I was also hard starting at times (longer than normal cranking) and when it did start and I'd give it gas (in park) to clear it up, it would blow black smoke. Then it wouldn't start at all; just crank over. I got to messing with it today and the first thing I did was remove the Idle Air Control Valve and clean it with carb cleaner. It was carboned up pretty bad, but cleaned up well. I reinstalled it and the Jeep immediately started, but ran a little rough because I had been cranking on it prior. I cleaned it out...blew all the black smoke (fuel) out. I idles almost great in park or neutral, but does stumble when I give it gas. In gear, it idles fine, but when I move and come to a stop it misses and stumbles. It drives down the road fine.
When I go to start it, I crank it for about 5 seconds with no start. I turn the key off and crank it again for about 3 seconds and it starts right up.
Any ideas?
 
low transmission fluid? low fuel pressure?fuel pressure regulator? catalytic converter..
1. check tranny fluid, low trany fluid can cause the torque converter to lock up and make the car stall.
2. checking fuel line pressure (fuel pump)do a fuel pressure test be sure it holds around 35-40 depending on if the vaccum line is on the regulator or not
3fuel pressure regulator test, leave fuel pressure guage on anf turn the car off... does the pressure drop off immediately or does it stick at 30-40 for a few minutes if it drops off immediately...findfuel return line(in front of the regulator, use channel locks and crimp the return line shut. turn the ignition on... do not start.(with the fuel pressure guage attached) then turn the ignition off . afterwards does the pressure stay high? if so thn the fuel pressure regulator is bad.
4. testing for blockd catalytic converter... simply remove the upstream oxygen sensor and drive it. if drivability improves and starting is better then there is a good chnce the convderter is bad.
 
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