Engine bogs down under load. 1988 Cherokee
 

Ok. I bought this '88 beauty from a guy in Fontucky. Then engine will run...only if i keep the gas pedal depressed a little while cranking it over. It cranks for a while...keeps cranking....then finally fires to life, reving at 3000rpms. Then if I let off the pedal..it dies. Now if I keep the pedal depressed for a little while and let the engine warm up, it will idle at about 1100 rpms. If I press the pedal down more than gradually, it will instantly bog down, as if there is too much fuel, or too much air going in, or not enough. In the engine comparment, when idling, sounds fine. But when you hit the throttle, the intake sounds like a vortex, or a really high powered vacuum. Then engine backfires out of the intake, and will bog down if the throttle is pressed open quickly. There is a new CPS, all the grounds have been scraped clean, wiring gone through over and over and everthing is good there. Distributor cap looks worn, but still usable. Plug wires are all mismatched. 2 orange ones with elbows, and 4 grey ones that look stock. Vacuum lines look good and are in tact. The tempgauge inside the vehicle is bottomed out and won't move, no mater how hot the engine. The oil pressure gauge is mxed out at 80psi, but it fluxuates as the jeep is cranking. gas gauge works fine....not much in it...and voltmeter is good. I took the cat off at the end of the exhaust downpipe, and it didn't do anything to the engine. There is a new fuel filter as well. Could it be the plug wires? Let me know what you guys think. I rolled and sold my last one and am having withdrawls from not being on the trail. Help me out please. If this is posted in the wrong spot let me know too.

Thanks fellas

First congrats on getting back in the game ,new to you jeeps or any car that has problems,start with the basics. I would do a compression test to get a base line to compare too years from now ,then look at the timing,I know you can't adjust it but it could be off a tooth at the distributor,might still run but the computer might not be able to compensate.

Thank you. I love these dam money pits.

Alrighty. I did some testing. The compression looks good. Although when I tested the fuel system, not so good. The gauge read 17PSI at the rail post regualtor, and ~20 out of the pump. Like I said the filter is brand new, so i'm going to assume the fuel pump. Once that is in I will post the results. I'm crossing my fingers. I have the lift, exhaust, CB, lights, everything is just sitting in my garage waiting to see if I can get the engine going. Come on baby!!! lol

Hopefully it's something that simple,you wouldn't need someone to keep all thoughs parts from Getin to lonely while your wrenching on it do YEA ? LOL

Gas tank is coming down tonight. What do you reccomend I clean it with? Do they have special solvents for gas tanks or something? Or will dish soap work? lol And I found a fuel pump online for un der $40!! I'm stoked. Will post results soon.

Most any fuel treatment will work,I've had good results with berrymans b-12 chemtool seems to really resolve the varnish.but that's just my opinion,hope the fuel pump worked

mine does this alot due to an 02 sensor failure. I hit it when installing a glass pack and it doesn't read right, its a common problem for you to try to take off and it just bogs. Mine still does it b/c i haven't fixed it. Both of my old cherokee's did it (until i replaced the 02) and my sister's still does it.

Try a new battery too, my battery caused mine to start but die for the next 15mins of driving. I had to put it in neutral (its an automatic) just to rev it at lights and stop signs, then drop it to drive to go.

alrighty. It was the fuel pump. I popped the new one in, and turned the key, and it fired right up. I also put the lift on, painted the flares, new radiator, a couple new sensers, fuel filter, open cooling conversion, lights, and removed the carpet. It's almost trail worthy, IMO.

how did you do the open cooling conversion? i have been wanting to do that to mine.

I believe there is a thread on the forum on how to do it, but you mainly need a heater control valve for a new XJ, with the open cooling system, a new radiator (or just an in-line radiator cap), the resevoir bottle and some misc. hoses. That all I used anyway. Other people reccomend replacing the thermostat and water pump, but I don't have that kind of cash right now. Good luck!

Nice Jeep. Good Job.

thanks for the info

You did pretty good on painting those flares...
Blends well with your tires...

Thank you. I'm going to be trimming the fat (fenders) tonight. Give the bumper corners a shot of paint as well.