Why Would My Jeep Die / Stall & Does Not Have Acceleration Or Power To Go Over 45 Mph

Posted in Ignition Systems

’90 Jeep Cherokee (not a grand) 4 liter 6 cylinder

I was having a lot of problems with it not starting and with it dieing once it started, so I replaced the fuel filter and still had the problems so I replaced the fuel pump and cleaned all the spark plugs. Wow what a difference! The Jeep ran great for about a week or two and then slowly I started having other problems, Jeep dies when coasting down hill (I shrugged this off as no big deal popping it into neutral and starting it right back up) Then the Jeep started to act like it was losing power while going down the road but always recovered and drove fine. This started happening every time I drove. The Jeep also had a very slow crank when starting, it would act like the battery was dead but then would start right up. (not cold outside battery not dead) When driving the Jeep it runs better if i put it into neutral and keep it at a high RPM while braking. Also once I get going down the road it tops out at 45 MPH and stays at the same RPM (unless put into neutral of course) I’m not sure what RPM it’s topping out at, just don’t remember.

I researched a lot of possible things, the list of what could be wrong with Jeeps is endless it seems. If you can rule out something for me or send me starting in the right direction it would help. I’m 19 and don’t know much about working on vehicles but I’m learning & I want to do my own work and need some guidance.
– rotor, cap, coil, crank shaft position sensor, engine control unit, crank angle sensor, wires, plugs, oil, battery, idle control valve, need to clean throttle body, need to clean injectors, relays, check 20 amp fuse for the ECU from the panel under the hood, MAP sensor, Idle air control sensor, Idle air motor sensor, Idle air control valve, throttle position sensor, do a fuel volume check find out what the pump should be pumping in 30 sec or 1 min…, O2 sensors, heated O2 sensor, catalytic converter, cam shaft position sensor, vacuum leak.

but if one of these things were the source of the problem wouldn’t it come on suddenly? Not slowly… With the exception of the idle air stuff and the vacuum lines.
Could there be something lodged in my fuel line? Lodged in the pump? (the gas tank is FULL)

I think I’ve found place where part of my vacuum line is missing, small black tube sucking in air, what now??? How do I figure out where it’s supposed to go? How do I find the vacuum line schematics for a 1990 Jeep Cherokee and how do I read them?

Additional note: My Jeep has for a very long time had a high idle problem, idles up really high sometimes when i put it in park. This comes and goes and to me isn’t a big deal. Is it possibly related?? I’m thinking Idle air control here.

Thank you for reading this, any advice, help or guidance is really appreciated. Or if anyone could rule out some possibilities from the list I’ve composed that would be a huge help as well. Again thank you for reading and replying.
I doubt it’s the starter I already replaced it not long ago

There are 7 Answers for "Why Would My Jeep Die / Stall & Does Not Have Acceleration Or Power To Go Over 45 Mph"

    1. Wilfred Fizzlebang says:

      Throw a bottle of fuel injector cleaner in your tank. I heard of a similar problem like this before and it was the throttle sensor

    2. LOTUS says:

      i have a problem with my 2004 jeep tj. it kinda sounds similar but mine turns on just fine, but runs really rough and i have no power ,its consistant, and after a while it burns out my injector fuse, this problem atarted gradually and increased in consisitancy with time,(months time). i have changed out coil,spark plugs, fuel pump. i am really fustrated, someone told me it was my pcm. ONBOARD computer !! , im near to giving up. , idk what else to do . NOONE really knows what is wrong, everyone just wants to take your money! it sucks!! i guess thats what i get for driving like it was indistructable !! , my jeep is but not my dumb PCM, (computer) IS !! how gay

    3. Noah's Ark says:

      I could list more things to look at like your starter if your battery is good … But the best advice for you is this . First off you need a good service manual if your going to do your own work … This is a dire necessity… Without it you have nothing to go by .. Find a good service manual on e-bay or at the very least buy a Haynes one at your local automotive store … This will tell you where that vacuum hose is supposed to go . Next look up a local jeep club near you and ask them if someone could look at your jeep to help you … Your Idle issue sounds like the same problem i had on my 89 cherokee ,. You have several issues going on that you need help with … You need a good jeep mechanic who you can trust … Try the jeep club first because their members are always trying to help all jeep owners … That’s what we do … Good luck

    4. kwhip3 says:

      I think it’s your vacuum advance (and if you have a missing vacuum line…). Anyway, the obc is monitoring the vacuum advance and won’t let your RPM exceed the timing advance. The vacuum system also controls the idle speed and many other functions.

    5. Ziggy says:

      sell it, and buy a new one

    6. Tilen says:

      Sell it or Junk Each and Every Part- JEEP.

    7. Steve A aka StvDiego says:

      What you describes sounds like it could be vacuum related. The randomness could possibly be caused by the ECM, maybe.

      First thing to do is to make sure your vacuum system is hooked up properly. Remember that the 1990 XJ has a different engine than the ’09 Wrangler

      I have a vacuum diagram, I’ll look into scanning and posting it.

      In the meantime, head over to Jeepforum,.com and go to the Cherokee Technical area, scroll down the page, it’s not quite halfway down. Years of experience to tap into and you may even find some local Jeepers to lend a hand