Fuel Pump????

[DanC7734]

Hey, i own a 2001 Cherokee, and my engen will turn over for a long time befor it will finally start, or i let it go, then try again and it will start., is this a fuel pump/filter problem or somehting greater? she has about 50K miles

[JDPascal]

If this is a warm restart problem, fuel pressure could be leaking down when the engine is off. Could be at the injectors (one or more leaking) or at the pressure regulator or the fuel pump module.

Have a tech do a static pressure test with the engine off (or get a gauge and do it your self)


Pressure should not be less than spec after a certain time. You'll find that in a manual here ....http://www.lunghd.com/Downloads_and_Links/Downloads.htm

It is normal for the pressure to go to 0 when the engine cools down. Just let the key sit in the run position for 1-2 seconds before moving to the crank position.

JD

[JDPascal]

O ya -- Welcome to AF

JD

[DanC7734]

Its cold start only. its fine with warm start

[SComp23]

Anyone know what this could be? I am having the same problem and was wondering what it is. In the morning, after the truck has been sitting for a while, it cranks quite a few times before it starts up, but if it has been running for a while, and I shut it off to go into the store and come right back out, it starts up just fine. What could this be? My truck also has around 50,000 miles on it. Thanks guys.

[JDPascal]

Hey SComp23 & DanC7734

Next time you go to start it cold, turn the key to the RUN position and let it sit there for several seconds. Listen for the pump to run for a few seconds to pressure up the lines.

After counting to 5 (suggested), crank the engine and note if there is an improvement in the start (shorter cranking time).

If there is, you may need to have the list of fuel pump tests performed on your system to find any weaknesses in the components.

Unless you really want to just replace the fuel pump and hope for the best, it is better to identify where the failure is originating from.

JD

[Carlson327]

I had the very same problem. I would have to let it crank many seconds before it would start. I tried to turn and leave the key in the RUN position, but it never really helped. It would start quicker if I had it off only a couple minutes. Ran a fuel pressure test. The pressure was fine when the engine was running, but the pressure would nearly drop to zero within seconds. Anyway, I finally got tired of the problem and went ahead and replaced the fuel pump. It fixed the problem, starts right away now, and actually seems to run a little better (not sure if that's my imagination though). I dropped the tank to replace the pump, and I recommend that method. Trying to get the old one out and the new one properly placed inside would have been really tough with the tank in place.

Good luck.

[sswpriz]

I had the same problem with my 99. Eventually, my mechanic said that it would get to the point where it wouldn't start due to the pump not working at all. Ya, its the fuel pump !! It's in the gas tank. I let my mechanic fix this one, LOL !!!

[JDusen4211]

you can replace it yourself and save some cash... it isn't that hard. just make sure u don't have a lot of gas in the tank when you drop it, otherwise it is a real pain to move it around.

[JeepTrouble]

I guess then i should syphin my tank then, cause i can't really carry something that heavy.... Mine has the same issue, it's taking a long time to start, so i bought the fuel pump and it's sitting in the back of my jeep, lol, maybe i should change it before it gets too much worse, Does anyone know how long i have before it gives out completely, i'd like to run all the gas out of it before i drop the tank, will it run that long?

[muckachuck]

I have a 98 cherokee 4.0I6 that is experiencing the same problem... Sometimes it just turns over for 10-20 seconds before it starts. Then it runs fine. I've put in new plugs, wires, changed CPS... I just figured (eventually) that it was bleeding off fuel pressure when it sat.

I went out today and bought a fuel pressure tester from a local parts store. When I hooked it up to the schraeder valve on the fuel injection rail - it was 0. When I turned the key to the run position - the pressure would jump up to 45psi then go right back down to 0 when the pump turned off after 2 or so seconds.

With the engine running - I got a pretty steady 45 psi and it has been running fine with symptoms like this for almost a year.

ALso, when it takes a long time cranking - it idles a little bit "burbly" for 10-20 seconds and then runs great on a cold start.

ALso a couple of other questions? Is there any way to tell how tight the serpentine belt needs to be - mine just squeals a bit when it is started cold and the ac/fan is on full blast. But damn it already feels real tight.

How much is a new fuel pump? Should I get one from the dealer or try and find an aftermarket unit?

Cheers,
M

[Carlson327]

I bought the entire sending unit from an aftermarket parts place. It was about $150. To change it, I ran my 4.0 L about 275 miles to get as much gas out as I dared. When I dropped the tank, I used a floor jack to support it. It didn't have much gas left, maybe a gallon.

[jrn1023]

Originally Posted by Carlson327

I bought the entire sending unit from an aftermarket parts place. It was about $150. To change it, I ran my 4.0 L about 275 miles to get as much gas out as I dared. When I dropped the tank, I used a floor jack to support it. It didn't have much gas left, maybe a gallon.

Carlson, if you don't mind my asking, what module/pump (sending unit) did you purchase? I've seen two that can be purchased online, AirTex and Carter. Did you purchase new strainers as well? And finally did you use a special tool to pull the pump?

Thanks.

[Carlson327]

Jrn, I don't recall the exact model, but it was the whole sending unit....pump, strainer, everthing including the seal that fits at the port where the sending unit fits onto the tank. No special tool, just a punch to undo the locking collar (use some penetrating oil if it's crusty like mine). Also, the sending unit should fit one way. There's a place for the return port to fit down into, so just make sure that mounts back in. That's why I say it's much easier to drop the tank and do it, becasue if you don't, you cannot see inside that tanks to place it where it needs to go.