Jeep Enthusiast Forums banner
1 - 19 of 19 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter · #1 ·
I own a 1988 Jeep Cherokee Pioneer with a V6, 4.0L Engine. Far as I know, it still has mostly original parts.

Here's the deal:

We were driving toward the next large town in WV. My boyfriend had to hit the breaks quickly to avoid some object in the road. After moving around said object, the jeep suddenly quit. What I mean by that is the motor stopped, but the radio, lights, everything else was still running fine, no significant dimming. We tried to get it to start back after drifting into a parking lot of a church that happened to be right by the road and it will NOT crank. It is acting like it's not either getting enough fuel or something. It's firing far as I know, but won't start in P or N. :rantscream:

Although I'm not a mechanic, I was assuming it was "maybe" the timing belt/chain or the Fuel pump/injector. Usually, I can get a good notion as to what is wrong, but I just don't know how to fix it. :ghost:

Uh... help? If someone knows more than me about this, or needs details or whatever, reply. I'm watching this thread via e-mail and will reply when I can.:( :confused:

Thanks.
 

·
Premium Member
Joined
·
14,195 Posts
Try spraying some starting fluid into the air intake tube that connects to the throttle body. If it starts momentairily you have a fuel issue, if it doesn't test for spark. Let us know what you find. And you have the I6 engine, not V6. I assume it is turning over just not starting correct?
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #3 ·
It's trying to turn, just doesn't seem to either be getting fuel or fire enough to start completely. I don't know where the intake for the throttle body is. Care to explain?
 

·
Premium Member
Joined
·
14,195 Posts
The airbox where the airfilter goes has a large hose coming out of it and going to the throttle body, remove the hose from the airbox enough to spray some starting fluid in there and see if it will start. If it doesn't pull a plug wire and plug, then have someone turn the engine over while you hold the plug against the engine for a ground, with it connected to the plug wire and see if you have a nice blue spark. If it isn't getting spark I would lean toward the Crankshaft Position Sensor or CPS being bad. They can go out without warning and shut off the spark to the engine. http://www.jeepforum.com/forum/f11/crank-position-sensor-write-up-197260/
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #5 ·
XJ,

I'll see if I can't try the airbox idea tomorrow. My boyfriend's cuz actually suggested the crankshaft sensor issue just last night as well. It went bad one other time and we had to replace it just last year about this time. Hopefully that stupid thing didn't fail already. It might have just gotten dirty. If it did, then all we have to do is clean it and plug it back up.

What signs would there be of fuel pump failure? (please give explicit detail)
 

·
Premium Member
Joined
·
14,195 Posts
You could bleed the fuel pressure off the rail at the schrader valve. It looks kinda like a valve stem, and is on the drivers side top of the engine. It is a tube that connects to the injectors. Push the valve in(keep eyes away and protected) and let the fuel pressure off. Then turn the key to the on position and let the pump prime. If you hear the pump running turn the key off and push the valve again to see if you have pressure. This should let you know if the pump is working.
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #7 ·
WE tried all the options you have suggested. The spark plugs are sparking. We tried the fuel pump thing. My bf even crawled up underneath and listened to the fuel pump and it seemed dead. He checked the schrader valve and it was without pressure. Looks like it might actually be the fuel pump.

Do '88 Jeep cherokee pioneers have the kill switch or collision switch? I asked someone in Advanced Auto and they looked it up and said it didn't. Yes? No? My uncle keeps swearing it has one, but he could have looked at a newer jeep model online.
 

·
Premium Member
Joined
·
14,195 Posts
I would assume the fuel pump is bad, but you can run a length of wire directly to the pump at the top of the tank and power it straight from the battery. If it still doesn't work the pump is bad.
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #9 ·
Still... eliminating all other simpler possibilities... Does a Jeep have a Collision or Kill switch? If so, WHERE? My uncle is swearing that is the problem, but I doubt it. Trying to find out before I call a servicer Monday. If there is none, then fine... but I still gotta know.

Thanks!
 

·
Registered
Joined
·
379 Posts
I would assume the fuel pump is bad, but you can run a length of wire directly to the pump at the top of the tank and power it straight from the battery. If it still doesn't work the pump is bad.
Would defiantly do that first, replaced my fuel pump and it turned out to not be the problem.

I actually had a similar issue, although I haven't seen anyone else on here that had the problem I had.
I ended up pulling the computer out and there was a burnt diode inside. -unusual

after replacing it my fuel pump doesn't shut off, so I'm guess there is a short somewhere that caused the diode to die in the first place. The jeep fuel pump usually shuts off after about 5sec with the key in the run position but no crank. I assume the same would happen during an accident that killed the engine.

Added info: this did happen to me while driving it, same as you. In my case I wasn't getting fuel or spark, from this dead diode.
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #11 ·
To fir3chi3f

I actually had a similar issue, although I haven't seen anyone else on here that had the problem I had.
I ended up pulling the computer out and there was a burnt diode inside. -unusual
Would this computer be located on top of the motor near the accelerator cable? I have a gas pedal that has been sticking occasionally for months, as though someone triggered the cruise control. Thankfully, if one turns the Jeep to Neutral or Park, kills the engine, and restarts, it resets the issue. This could be part of the problem as well.

I think I'll be picking up a haynes repair manual at my local Advanced Auto. And no, I don't like Chilton books very well. I don't like their method of giving directions.

Nice use of numbers and letters, there. Creative. :)
 

·
Registered
Joined
·
379 Posts
The computer is the shiny box right above the gas pedal, I'd suggest opening it if all that xjfever said doesn't work because I found the computer to be a real pain to get back in and as I said it is unlikely with everything else that could fail.

Yeah and I wish I had armor too :p
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #14 ·
Cruiser--

Just called my local dealer and he told me that this morning about the impact switch. I was rather dismayed.

Where would I find the relay for the fuel pump? I know I ask a lot of questions, but I would rather learn the RIGHT way than be ignorant and attempt to fix it only to screw it up more. This is the only vehicle I own and I can't afford to buy another -- hence the questions. I hope it is something lower cost than replacing the fuel pump itself. My neighbor who owns a jeep as well said fuel pumps are between $50 and $70+.
 

·
Registered
Joined
·
379 Posts
A good investment before spending money on parts is a Haynes Manual 10-15$ I imagine. Better still would be the factory service manual but, I've seen those cost 100$ easy but say everything about everything.

The relay is under a cover on the passenger side of the engine compartment. I don't have mine out but the Haynes should tell you which one it is and to test you would just switch the relay with one you know works like high beams.
 

·
Registered
Joined
·
1,064 Posts
I am with you guys on the manual, and also the relay, i had a 90 limited, and it had a similar issue, and I went thru hell and beyond, and I ended up repalcing the relay out there and CLEANING up the socket it plugs into, that was my issue.. The Jeep would run fine, and then just shut off.. I had replaced the fuel pump on that particualr one earlier, and it was lil noisey, so I told Napa, and they repalced it under warranty, but it ended up not being that... i did coil, plugs wires, CPS, and so on,and so forth, and it ended up being that stupid relay and corrosion that formed in the socket thru the years..
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #18 ·
Nutter & firechief...

I think we'll check to make sure it's not a clogged fuel filter first, then check the relay and the fuel pump if it's not the relay or the filter itself. Hopefully we can try to get the thing running before my classes tonight... otherwise, I'm going to have to borrow someone's vehicle... Where's the tylenol? LOL
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #19 ·
Thanks Jeep-Peeps...

To everyone who's tried to assist us with our Jeep and its problem, thanks for your advice. :2thumbsup::thankyou: After we got the Haynes repair manual, we ran some tests and my grandmother helped me get the fuel pump we needed. And sure enough, soon as it was hooked up, BF just turned the key to On and the pump just kicked on instantly. He also checked the filter and it seems good for now. Maybe something just got sucked up inside and finally killed the old filter? Anyone's guess, there. Was able to make it to that concert for my music class tonight, so that's good. :thumbsup:

Funny thing, somehow flooded the engine when the Jeep was sitting on an incline (nose down) and fretted the crap outta me, since it was getting to the wire, time wise. So... BLAH! Aggravating. Thankfully, it was nothing bad.
 
1 - 19 of 19 Posts
Top