1990 Jeep Cherokee takes forever to start

[atfrith]

hey, i have a 1990 jeep cherokee and for the past couple months it has been taking me Jeep forever to start once i turn the key, i have heard that it could be a couple things, mainly either the starter or the fuel pump. Also, when sitting idle at a light or something my car seems to me trying to accelerate if that makes any sense. Like i will be sitting there, on the brake, and the car slightly bumps a little from time to time, i'm not sure if that has anything to do with the fuel pump or what. Any ideas?

[JKooshTJ]

I'm having the same problem. I'm tempted to say that it feels like the fuel isn't getting to the engine like it's supposed to. Mine even struggles when I'm on the gas, like it wants to go more but can't, then it's jolt forward. Did you get any kind of response on this one. Mine is a seriously abused 88XJ I just got.

[atfrith]

I havn't really noticed anything while the car is running so much, but then again maybe i have, lol, i havn't been paying much attention. It just seems like its having trouble turning over. Seems like my gas mileage has gotten a little worse too, any ideas anyone?

[matt919]

I would say the fuel pump. Eventually, the fuel pump will stop working all together, and your Jeep will not start.

[atfrith]

If it is the fuel pump is that something i could change myself, does it involve a simple switching out or would i have to take it somewhere, i am not too knowledgable of doing these types of things but if it is simple enough i probably can. Also, around how much will this run me?

[Saudade]

I would check/replace the fuel filter first unless you measure the fuel pressure and see that it's low.

When it cranks, does it crank slowly, like it's struggling or does it crank normal? If normal, how long does it crank before starting?

[GPN 05]

The whole problem depends on engine, and transmission. If you have a 4.0L Automatic... it will jump and idle heaver and softer at some points while stopped... If it's a manual it could be the slave cylinder. If it's a 2.5 /2.8 L engine... Automatic could be carburator problems, same with manual. The starter on all Chrysler made Jeep, take a while to start... it's Chrylser!!!! I have an AMC Jeep Chero and love it, most of the Chrysler parts on the Jeep suck, expecially the starter. I was having idle problems and kinda not enough power I guess you could say. I changed the points and plugs ( Spark Plugs and Cables) Air Filter, Oil, and Oil Filter and bought Injection Cleaner, from then on every 3rd fill up I put injection cleaner in it, works fine and great restored power and "umph" to my 87 Jeep Cherokee Pioneer with 470K Miles !!!! 4.0L 242 M Automatic with 242 Selec_Trac Transfer Dana 30 Front and Chrysler 8.25 Rear... Original Miles, Transmission, and Engine. Transmission Fluid never changed, and checked every 6000 Miles... Still as clean as a whistle !!! Jeeps Run Forever....

Corey's Philosophy :: Don't Get Stuck On Easy Shizite!!!!!!

[atfrith]

Saudade no it does not crank slowly like its struggling, it sounds perfectly normal, it just takes a while. It takes the longest in the mornings or after periods of time where it hasn't been driven like when its just been sitting for awhile, then it sometimes takes around 7-10 seconds. Other times it usualy is around 4-6 seconds, sometimes longer sometimes shorter.

[Dale Aeppli]

Originally Posted by atfrith

Saudade no it does not crank slowly like its struggling, it sounds perfectly normal, it just takes a while. It takes the longest in the mornings or after periods of time where it hasn't been driven like when its just been sitting for awhile, then it sometimes takes around 7-10 seconds. Other times it usualy is around 4-6 seconds, sometimes longer sometimes shorter.

HI, GET A GUAGE HOOK IT UP ON THE FUEL RAIL FITTING. TURN KEY ON GAUGE SHOULD BE 31-32 LBS. DISCONNECT FUEL PRESSURE REGULATOR ON FUEL RAIL, SMALL RUBBER HOSE PRESSURE SHOULD RAISE UP TO 39-40 LBS. SOUNDS LIKE FUEL PRESSURE REGULATOR MAY BE BAD. DALE [email protected]

[atfrith]

Hey all, i replaced the fuel filter today and also put some new spark plugs in. The fuel filter seems to have fixed the problem. Before whenever i tried accelerating while on the road the car would kinda jump forward as it were having trouble but now it accelerates smoother than it ever has, it hasn't taken awhile to start either, but the real test will be to see how it starts in the morning tomorrow.

[atfrith]

Well, nevermind the previous post, it took roughly 8-10 seconds of cranking to start the car this morning, what the hell is wrong, ughugh, i'm getting really annoyed. I guess it is the fuel pump then, i have no idea how to install a new one myself so i guess i'll just shop around places around town and see how much it will run me. damn

[bill99hawk]

Try turning the key into on position for about 5 seconds and then start up. If you start rather quickly, then this is pretty much normal.

[atfrith]

Wow, thanks for the tip bill99hawk, i'll be sure and try that in the morning and let you know how it goes.

[Edbrooks]

Following from my own experience with multipoint injection system and my long and tedious learning curve!

1. If you have a fuel pressure gauge (actually some AC gauges will work if their threads will match the pressure port on the fuel rail) attach the gauge to the port.

Turn the switch on. The pressure should rise to around 31 psi. (Do not start the engine.)

Now turn the switch off. The pressure should remain high for approximately one half hour. If the pressure drains off in very short time, like couple of minutes, the fuel is probably leaking back past the check valve in the fuel pump. If the pressure leaks off more slowly but still drops in five minutes or so, it is probably a leaking injector.

To repair the fuel pump you must remove it from the gas tank. To see if it is leaking back, disconnect the fuel inlet to the fuel rail (be very careful not to lose the o-ring!!! Pull it out with a very small screwdriver before you go further!) Put your finger or thumb over the fuel line from the fuel pump. Have an assistant turn the key on and back off in a second or two. If you can keep the fuel from squirting out the line by hoiding it with your hand, the pump is leaking back and has to be repaired.

2. To check injectors for leakage: (And this sounds like your problem, as I had it on mine with same symptoms)

This takes some work but it is worth it! Remove the fuel rail and all injectors from the engine itself, but leave it attached to the fuel pressure regulator (you will have to detach that from the manifold) and to the fuel line. Place a long sheet of cardboard under the injector tips. Turn the ignition switch on. Leave it on a bit, but do not start the engine. If an injector is leaking, you will see a wet spot on the cardboard. Replace that injector. Injectors can be cleaned, but often it is not worth the effort.

3. If you do not have a pressure gauge to attach to the fuel port, you can try this. Remove the port cap so you can get to the port easier and faster. Turn the ignition on. Let it sit on for five or six seconds, then turn it off. Wait about one minute, then press the needle in in the fuel port. You should get a very good pressurized flow of gas for a half second or so. If you do not, either the fuel is leaking back past the check valve in the fuel pump, or you have a leaking injector.

My guess is you have a leaking injector, maybe several. Here is a 'sort of' check to see. Run the engine. Then shut it off. Attempt to restart it after about one minute. If it is difficult starting, stop trying, but push the accelerator pedal to the floor, the same way you would on a carbed engine, and hold it open a few moments. This allows fuel from leaking injectors to evaporate quickly. Then try the engine again. (hold the accelerator wide open!) If it starts considerably better, the injectors had probably been leaking, causing too rich a mixture.

4. Final test. Requires the pressure gauge. Start engine. With the engine running and the pressure guage attached, briefly remove the vacuum line from the pressure regulator. Fuel pressure will rise quickly. If it does not, the regulator is bad or the fuel pump check valve is bad.

Good luck
ed

[atfrith]

Cool thanks for all the info Edbrooks, regarding the latter part of #3, it usually only takes awhile to start with the initial startup of the day, and after periods of time where it has just been sitting, if i were to go outside in the morning and start it up it would take awhile, but if i turned thhe car off right after that and tried starting it again it would start up just fine.