utah_xj
12-12-2007, 08:45 PM
I have an 87 jeep Cherokee. It has the 4.0 I6, fuel injected. I am having a number of problems and don't know if you have any suggestions.
First off, I am getting 11 miles per gallon. I have a 4" lift with 33" tires. My engine has around 210,000 miles on it. I change the fluids and clean my filter regularly, also I keep my foot out of it when I drive, but I am sill getting really bad gas mileage! Is this normal? If not any Ideas?
Next problem...... My engine miss fires only at idle. I have replaced and gaped my plugs, new wires, new cap and rotor, checked my map sensor, new oxygen sensor, I have used "seafoam" in the intake, oil, and gas. I checked and replaced all of my vacuum lines (and did away with that vacuum connector) I replaced my fuel injectors, checked my fuel regulator. I did a compression check; all of the cylinders were within the recommended 20-psi variance. I swear I have done everything and still it miss fires at Idle. I'm about ready to give up!
Problem three...... Last time I took it in to get the emissions checked it failed miserably!!!!! I replaced my egr valve and my cat, it fixed the high rpm test but it kept failing the idle. I think it might have something to do with it miss firing if I can ever figure that out.
Do I need a new motor?
Please help!!!!!!!!!!!
First off, I am getting 11 miles per gallon. I have a 4" lift with 33" tires. My engine has around 210,000 miles on it. I change the fluids and clean my filter regularly, also I keep my foot out of it when I drive, but I am sill getting really bad gas mileage! Is this normal? If not any Ideas?
Next problem...... My engine miss fires only at idle. I have replaced and gaped my plugs, new wires, new cap and rotor, checked my map sensor, new oxygen sensor, I have used "seafoam" in the intake, oil, and gas. I checked and replaced all of my vacuum lines (and did away with that vacuum connector) I replaced my fuel injectors, checked my fuel regulator. I did a compression check; all of the cylinders were within the recommended 20-psi variance. I swear I have done everything and still it miss fires at Idle. I'm about ready to give up!
Problem three...... Last time I took it in to get the emissions checked it failed miserably!!!!! I replaced my egr valve and my cat, it fixed the high rpm test but it kept failing the idle. I think it might have something to do with it miss firing if I can ever figure that out.
Do I need a new motor?
Please help!!!!!!!!!!!