OK guys help me out here please

[gr8lite]

Still having issues!! This morning XJ wouldn't start , fuel pump wouldn't "pumpup" on initial pre starter engagement. I wiggled wires here and there , nothing. I swapped fuel pump relay , nothing. I did find a 15a mini fuse labeled IGN blown replaced it. Still , nothing. after turning key on off on off about 100 times I finally heard the pump run! Then yes it did start!
Anyone have any thoughts on this!!!!!


1994 XJ 4.0 , 5 spd


HELP ........................................................

 

[HilltopXJ]

Cps...

 

[gr8lite]

the crank position sensor triggers the fuel pump ? Thanks

 

[Sparkman]

If the "fuel pump wouldn't "pumpup" on initial pre starter engagement" I would guess it has nothing to do with the CPS. AFAIK the CPS provides engine position information that the PCM uses to determine spark and injector timing, but not power to the fuel pump. I would disconnect the connector at the fuel pump and connect a meter to it. You should see voltage for a couple of seconds after the key is turned on. If you have voltage you have either a bad pump or connector. If you don't see voltage trace your way back through the system until you find the fault.

 

[gr8lite]

Thanks Sparkman that makes sense to me! Are fuel pumps commonly bad in these rigs? I priced them oem is $ 370. aftermarket rebuilt is $114. Also am I correct in understanding I can change it without rmoving the tank ?

 

[89xj]

Thanks Sparkman that makes sense to me! Are fuel pumps commonly bad in these rigs? I priced them oem is $ 370. aftermarket rebuilt is $114. Also am I correct in understanding I can change it without rmoving the tank ?

yes you can change it without removing the tank. have you checked the fuel pressure on the fuel rail and regulator?

bad fuel pumps seem to be a fairly common problem.

 

[Matthew Currie]

Thanks Sparkman that makes sense to me! Are fuel pumps commonly bad in these rigs? I priced them oem is $ 370. aftermarket rebuilt is $114. Also am I correct in understanding I can change it without rmoving the tank ?

I haven't been following your case up till now, but have you checked out the ignition switch and the wiring harness to the fuel pump? No point paying and pulling if all you have is a corroded connector pin or something. The fuel pumps on these rigs do go bad from time to time, but I wouldn't say it's necessarily common. I've had a couple that went over 200 thousand miles. My stepson's 93 became very noisy at 180-odd, but didn't fail before I replaced it (with a used one).

You can replace the fuel pump without pulling the tank, but it's a nuisance, and having done it once I would opt for dropping the tank. The position for getting the pump in is very uncomfortable, and it's very hard to get the pickup for the unit to seat in its little hole at the bottom of the tank when lying on your back, reaching around the axle, etc., and if you use a new O-ring, as is recommended, it can be very hard to get that seated right also. By contrast, it's quite easy to do with the tank on the ground, and the tank isn't that hard to get in and out. If you live in an area where rust occurs, there's a strong chance you'll shear off the hanger bolts removing the tank, but on the other hand, you'll have a chance to get the corrosive muck and sand and mud off the top of the tank and perhaps extend its life.

By the way, whichever method you choose, remember to use a non-ferrous punch to remove the locking ring on the sender. You will have to knock it pretty hard, and it's likely to slip or miss, so we don't want sparks and consequent booms and "thinning of the herd."

 

[RichP]

Failure rate on aftermarket fuel pumps is much higher than the OEM ones, there are a few things I will only use oem for, clutch slave, fuel pump, tune up stuff, water pumps. The tune up stuff cause is always works and the slave and fuel pump because they are such a PIA to do. What good is a lifetime warranty if you have to drop the tank or tranny every few months. I'm not sure on a 96 but the NSS could have something do to with it, when you turn the key on do you get any electrical activity at all, gauges, radio, etc ?? There is also switch down near the brake pedal that gets involved here too...

 

[89xj]

Failure rate on aftermarket fuel pumps is much higher than the OEM ones, there are a few things I will only use oem for, clutch slave, fuel pump, tune up stuff, water pumps. The tune up stuff cause is always works and the slave and fuel pump because they are such a PIA to do. What good is a lifetime warranty if you have to drop the tank or tranny every few months. I'm not sure on a 96 but the NSS could have something do to with it, when you turn the key on do you get any electrical activity at all, gauges, radio, etc ?? There is also switch down near the brake pedal that gets involved here too...

no nss on a 5speed.

 

[family XJ]

I am kindda in the same boat. My brothers turns over but won't start. I can hear the pump turn on but when I took off the fuel filter nothing was coming out and the filter was good. I checked the wires and the current was good. I am just going to replace the pump myself and see what happens. I truely think it is the pump going bad on you. Don't know if this helps but it's another current senario........DuG

 

[RichP]

no nss on a 5speed.

There sure is one, right on the clutch pedal and they do break...