Fuel Problem need HELP!!!!

[JeepXJ_90]

I have a 1990 XJ with the 4.0 NonHO almost completely stock (K&N and Flowmaster thats it)Yesterday was the start of the cold weather. noticed some gas fumes inside the jeep. today noticed them again, poped the hood and notice 3 fuel injectors leaking. no problem, drove down to the store and got some new o-rings. come home pop of the injectors replace all of the o-rings, put the system back on, then turn the jeep on. has trouble idleing kinda sputters (cloged fuel injector?) let it run for a minute to see if it clears up, it dosn't. there is also black smoke coming out of the exhaust pipe. check the injectors again for leaks there aren't any. check plugs for the hell of it. they are fouled out lots of carbon (black) running rich? change them for the hell of it take the injectors back off clean them put it back on engine still can't idle but its a little better. take it out for a drive around the block (still black smoke) but there is no power loss. it hauls A$$ when you stomp the petal. slow down to a red light and again the idle sucks what is my problem a bad fuel injector or something.


o i also ran some seafoam in it to see if that helped and it did a little, it still isn't running right though

[Hellbent]

sounds like the injectors could be leaking internally. if they're original and you've got the $$$ kicking around, i'd just replace all six with the bosch 4 pintle 5.0 mustang injectors. you can pick up them up pretty cheap, i got mine off ebay. and yes, it is a direct plug-and-play swap.

[churky89]

Could also be:
moisture in the fuel
Clogged filter

[JeepXJ_90]

i think that it might be the fuel pressure regulator so i got a new one and will see if that fixes it

[aparke4]

are the 5.0 injectors any bigger in terms of psi?

[Hellbent]

i believe the stock are something like 18.6 lb/hr injectors, and the 5.0's are rated right at 19 lb/hr. they are rated at the same fuel system psi.

[Saudade]

When I did mine on my '88, there was a lot of carbon build up all around the tips and in the injector bosses. I spent quite a bot of time cleaning everything out. Maybe when you changed out your o-rings, you knock all that crap into the cyls.

BTW: I bought a set of 19# Ford injectors on eBay.

[JeepXJ_90]

well i replaced the fuel pressure regulator and it helped a little bit.
however my idle is still off and black smoke is still coming out

[langer1]

Do you have vacuum at the fuel pressure regulator?
And also make sure the MAP sensor vacuum is still connected.
One more thing there are two holes in the TB make sure the MAP vacuum line in in the correct one.

[Jess]

pour a can of seafoam through the throttle body and it should clear your problem...I just had the same problem with a 94. The seafoam left a one foot circle of black in the grass under the tailpipe and smoked like hell for about 5 minutes and now I have perfect idle and no smoke.

[JeepXJ_90]

thanks for the help guys i got the rig back up and running tonight
turns out when i took the injectors off i managed to break the MAP sensor air tube that runs from the throtle body to the sensor
fixed that and put some new plugs in and it runs great