Backfiring up front
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Joined: Nov 2008
Posts: 587
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From: Tooele, UT
Year: 1995
Model: Grand Cherokee
Engine: 4.0
Well I was still having the problems as well as stalling after driving for awhile. So I pulled out the fuel pump and the hose on the from the pump to the line was barely hanging on. And it was pretty deteriorated, so after switching that and a new strainer it started within 2 seconds. And the pressure was so high the regulator started leaking. I guess I crushed some of the o rings when I did the injectors but there never was enough pressure to leak. So the backfire is gone i think it was pulling air into the fuel rail with weak pressure and causing the problem. I hope this helps anybody else.
Just wondering. My Jeep is having that same problem right now and funny thing is, is when this thread finished is when my problems started happening, too bad I didn't look here first. Well! Anyways, my jeep was backfiring nonstop, loss of power and spewing oil (I'm guessing out the breather) back in December of last year. We changed out the Fuel Filter, Pump, Gas Tank (Found a ton of crap in there), Distributor Cap, Wire, Plugs and even changed out the oil. Right now it's just spewing oil with an occasion backfire. We got the power going again and I was just wondering, do you guys think it was maybe the Intake Manifold Gasket that was the root cause to this issue or possibly the Fuel Injectors? I'm asking because we don't know what would cause the jeep to spew oil on top of the engine
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CF Veteran
Joined: Sep 2008
Posts: 1,053
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From: Ft. Lewis, Wa
Year: 1987
Model: Cherokee
Engine: 4.0
Maybe pull off the valve cover and clean up any oil build up. It will get real thick on the inside of the valve cover and not let it breath.
I believe I may have fixed the issue, I changed out the Oil Filler Cap and the Breather along with the Grommet and it seems to be fine, just need to clean the top of the engine and get all that old oil off of it. I'm gonna feel really dumb for asking this... but wouldn't I be spilling oil if I took the Valve Cover off? I'm really new to the whole working on cars/trucks thing so this is my first project. Definitely sweet and sour, nice to work on the Jeep but bad that my Jeep isn't working correctly.
Last edited by Skowboarder; Jun 25, 2009 at 06:52 PM.
Thread Starter
CF Veteran
Joined: Sep 2008
Posts: 1,053
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From: Ft. Lewis, Wa
Year: 1987
Model: Cherokee
Engine: 4.0
You won't loose any oil pulling the cover off. Underneath those grommets is the main part you want to clean up. It's like the rear main seal at some point all of us are going to have to do it. Cleaning the valve cover should only cost you the price of the gasket. And if you do pull it off check all the bolts from time to time they will loosen up.
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Joined: Apr 2010
Posts: 3,966
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From: knoxville, tn
Year: 2000
Model: Cherokee
Engine: 98 4.0 I6
to the op...if you still aree watching this thread...did you replace the manifold gasket...or just took care of the fuel issue...i am having the same issues ..will pop up front during the first few minutes and generally run normal in exception of here and there it will have hiccups...i am thinking the fuel pump has got some rust causing the issues...plan on starting with the fuel assembly and go from there.. the jeep sat for over a year with a blown 4.0 and i think that is what the issue stemmed from ...
going to start doing my injectors myself, i did it the long hard way i knew i had a fuel delivery problem so i changed pump, filter, regulator.... still doing same issue backfireing threw airbox and exhaust, wont start, exhaust is brand new w/ no leaks.... so i changed MAP,CTS's , TPS, CPS, plugs rotor, wires, checked all vacum for leaks everything looks good, checked all ground wiring. decided to put spar injectors i got off a 96 intake.... my jeep is a 95.... do injectors have to match computer year ? because it seemed to run lil diffrent ..... but still no solid start..... thinking about buying new injectors before i decide its a ECU.... any thoughts? any at all?
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