billybad05

I have a 98 Cherokee 4.0 with 128k, runs great. I just changed all six injectors and somehow im still getting fuel in my oil. Any ideas? also i have no codes. Should i replace the fuel pressure regulator?

thanks in advance,
billy

EVcherokee

Do a compression test and test your fuel pressure before changing anything. Also, pull the valve cover and pay attention to pressure bleed-off when the cylinders are pressurized. Look for any bubbling/spurting especially in the drainback holes. I've never heard of this happening on these motors, but sometimes head gaskets will blow from the cylinder to where the oil is, also it could be a crack. They don't alway go to a water jacket. I've also seen gaskets blown to outside the motor, which sounds like an exhaust leak, but smells like gas.

billybad05

i can do a compression check. never done a fuel pressure check, how should i go about it? I wondering if i should just take it somewhere. What really makes me mad is it runs great but somehow there is something wrong with it.

TrekkerJmm

First off its a JEEP and nothing ever makes sense...lol. Second , all you need to do is put a fuel pressure gauge on the fuel pump rail next to the valve cover...Good Luck...Tj

91familyxj

You can rent the gauge for most parts store and its free. Well you have to put the money down then you get it back. its worth a shot befor you pay some one

EVcherokee

Billybad05, if you feel comfortable pulling the valve cover and doing a compression check, doing a fuel pressure check is a breeze on these motors. I'm not %100 on a H.O. motor but there should be what looks like a big tire stem sticking off the fuel rail. Its covered with a knurled "stem cap".Thats where it goes. Be sure to bleed the gauge too, there should be a little button or valve on the gauge to drain air. Follow the haynes manual for the proper psi ratings and procedures.

DON"T DO THIS ON A HOT MOTOR!!

You're gonna spill a little gas and if it hits the exhaust manifold, you could turn an easy procedure into an insurance claim. Whenever I got gas flying around I've also got a fire extinguister around and lots of rags. Make sure its rated for BC or ABC. I carry a ABC rated in the cabin all the time. Safety first!

One more thing, IF you ever do use a fire extinguisher on any part of your rig, wash it all off with water asap. The powder is mildly corrosive, but loves to eat up electrical parts. XJ's have enough electrical issuses and don't need anymore. Dumping water on a gas fire can just spread it..

billybad05

I did a compression check from the front to the firewall, I came up with the following: 150, 151, 148, 150, 158, 160

I think these are good numbers, so i would guess it would rule out a ring problem, what do you guys think?

thanks

billybad05

I guess im probably looking at a bad head gasket, cracked head or bad fuel pump assembly?

Hommersimpson

how much fuel in oil ?

billybad05

well after i drove it 44 miles, the dipstick read 1/2 quart to high

EVcherokee

Starting from what/where? Do you have 1/2 quart + of gas in your oil?! If you do, stop driving it now or your bearings will go bye-bye. Did you lose 1/2 quart of oil in 44 miles?!? Did you pull the valve cover and look for bubbles like I suggested previously? have you checked the fuel pressure?

You can start swapping stuff out if you want, but it can get really expensive and get you no where. I know this from experience. The more info you give us, the more we can/willing to help you.

billybad05

1/2 quart of gas in the oil after 44 miles. the dipstick raised by that amount. I havent checked the fuel pressure or anything else yet. im not driving it, havent since tuesday.

Hommersimpson

pull the injecter rail with the injecters in it... unplug coil and have someone turn key on watch what happens... then turn it over very shortly and watch what happens... then turn key off and see waht happens....

billybad05

i pull the rail in a couple hours when my wife can help. thanks for your help, ill post what i find out.

billybad05

okay i pulled the rail, with the key in the ON position: nothing came out of the injectors. When turning the key over (cranking) gas sprayed out of all six injectors, then less than a second later started spraying out in the firing order. With key off nothing came out of the injectors.

Is this what i should be seeing?