Another thing to rule out is your Catylitic converter. A converter that has broken internally or is completely clogged can cause an intermittent power loss,since it is a retriction on the engines ability to expell spent exhaust gases it will worsen with increasing RPMS. Just a thought for you. The black soot thing does sound like rich running, O2 sensor could be a factor there but not until it gets warm....any exhaust leaks that you can see/hear? Any unplugged/broken vacuum lines? CEL?

 

LOL Yeah I have a bunch of vac leaks.. Its a 89 so I have CEL codes...

When I first bought it when I was 15 it had leaks.. Nevr fixed them all but also never had a problem... Not sure on the exhaust leaks though... I dont think i have any.... Im alos pretty sure that I am all cat-converter free... But when I am giving it more gas it sounds like there is a clunking coming from somewhere in the exhaust system....

 

Anyone else have any ideas??

 

Hook a hand held pressure gauge up to the test port on your fuel injection rail and turn the ignition switch to on. Good fuel pump indication is 31 psi +or- 1 psi. ANYTHING else and you have a bad fuel pump. If this indication is good, pull the vacuum line off of the Fuel Pressure regulator and the pressure should jump up to 39. Again, anything else is a bad Fuel Pressure Regulator. Hopefully this helps you find the bad part. If not, you'll definitely rule out a couple of spendy parts without just throwing parts at your Jeep.

 

Thanks for all the advice.... But where is the test port on my fuel injection rail at?

Wheres the Fuel pressure regulator at also??

thanks

 

http://www.lunghd.com/Tech_Articles/...iagnostics.htm

mark

 

my 89 seems to do something like that when u touch the gas pedal if shes not warmed alil she will bogg right out and almost die but once shes warmed up for a couple mins the throttle is right there and ive already done a tune up replaced vaccum lines fuel filter oil air filter and tps dident inprove that. Mind u i have a rotted out heat riser tube and a slight exhaust leak was patched once and is leaking at the patch pipe hope u figure out what is causing that would like to hear

 

thxs fro that info.. Will perform test on it ASAP

 

I would bet bad o2 sensor or faulty injector.

 

My 97 XJ would occasionally cripple itself up as though it were getting no fuel. Twice I limped into a repair shop barely running, but it would fire right up for the technicians with no error code and good fuel pressure test.

On the third occasion I struggled in to the shop and with it running roughly at idle they managed to get an error code. BAD O2 SENSOR! Incredibly fast and simple fix, and completely solved the problem.