Jeep Cherokee Electrical Problem

I am in need of help with an electrical problem on my 88 Jeep Cherokee
4.0 L, 2wd, 5 speed standard trans., with AC. The vehicle sometimes
will start without problem, but as soon as ANY load is put on the
electrical system, such as brake lights, wipers, dome lights, putting
the vehicle in gear, will stall the engine. At that point, the engine
will not restart. There is no spark from the coil. When the engine is
running it throws a GREAT spark. Also, when the engine is running the
alternator does not charge.
A new battery has been installed. A new alternator has been
installed, a new coil and coil module has been installed. A new
distributer cap and new plug wires have been installed. Six new
relays have been installed and all fuses under the dash have been
checked and/or replaced. After the coil and module were installed it
ran GREAT for approximately 15 miles and then engine stalled,
displaying all of the above stated problems again. I had to have the
vehicle towed home.
It should be noted that the only draw on the engine that does NOT
cause it to stall is the AC. Running the AC at idle does not stall
the engine, but if the brake pedal is depressed the engine stalls
immediately.
What am I missing and what do I need to do to solve the problem.
Robert

I believe that your crankshaft posiion senser (CPS)
is bad. it cost about 30 bucks and will cause eratic starting and running.
It has a wire harness to plug into a spot under the hood, on the driver
side near the firewall, and it fits into a hole in the upper drivers side
of the bell housing.
It is hard to get to and requires a long extension and a flexible joint.
two screws hold it in place(10 , 11 or 12 mm)
be care full not to drop the screws into the hole while replacing
them.(have to pull the tranny to get them) the sensor end just sets in the
hole in the bell housing and is positioned by the mounting screws.
i am 95% sure this is your problem.
john




"RAD" <[email protected]> wrote in message
news:[email protected]...
> I am in need of help with an electrical problem on my 88 Jeep Cherokee
> 4.0 L, 2wd, 5 speed standard trans., with AC. The vehicle sometimes
> will start without problem, but as soon as ANY load is put on the
> electrical system, such as brake lights, wipers, dome lights, putting
> the vehicle in gear, will stall the engine. At that point, the engine
> will not restart. There is no spark from the coil. When the engine is
> running it throws a GREAT spark. Also, when the engine is running the
> alternator does not charge.
> A new battery has been installed. A new alternator has been
> installed, a new coil and coil module has been installed. A new
> distributer cap and new plug wires have been installed. Six new
> relays have been installed and all fuses under the dash have been
> checked and/or replaced. After the coil and module were installed it
> ran GREAT for approximately 15 miles and then engine stalled,
> displaying all of the above stated problems again. I had to have the
> vehicle towed home.
> It should be noted that the only draw on the engine that does NOT
> cause it to stall is the AC. Running the AC at idle does not stall
> the engine, but if the brake pedal is depressed the engine stalls
> immediately.
> What am I missing and what do I need to do to solve the problem.
> Robert

On Tue, 30 Sep 2003 20:06:57 UTC [email protected] (RAD) wrote:

> I am in need of help with an electrical problem on my 88 Jeep Cherokee
> 4.0 L, 2wd, 5 speed standard trans., with AC. The vehicle sometimes
> will start without problem, but as soon as ANY load is put on the
> electrical system, such as brake lights, wipers, dome lights, putting
> the vehicle in gear, will stall the engine. At that point, the engine
> will not restart. There is no spark from the coil. When the engine is
> running it throws a GREAT spark. Also, when the engine is running the
> alternator does not charge.
> A new battery has been installed. A new alternator has been
> installed, a new coil and coil module has been installed. A new
> distributer cap and new plug wires have been installed. Six new
> relays have been installed and all fuses under the dash have been
> checked and/or replaced. After the coil and module were installed it
> ran GREAT for approximately 15 miles and then engine stalled,
> displaying all of the above stated problems again. I had to have the
> vehicle towed home.
> It should be noted that the only draw on the engine that does NOT
> cause it to stall is the AC. Running the AC at idle does not stall
> the engine, but if the brake pedal is depressed the engine stalls
> immediately.
> What am I missing and what do I need to do to solve the problem.

I would start with the ground connections. Since it sounds like it
cranks OK, the battery-to-engine connection may be OK, but I would
start with it anyway - a bunch of the computer related stuff grounds
to the same stud in the block as that big lead (side of the block just
aft of the oil filter, heavy wire straight to battery negative). It
can be a real PITA to get out so grease up your vice-grips. It's a
stud that screws into the block and you'll likely have to fight
getting the nut off without twisting wires so be care of that. Next
in line - or maybe first, just to save possible work - is the braided
strap from the back of thead on the driver's side that connects to the
firewall. For both of those, clean the ends really well (as in get
them shiny) and see what that does. Also, check the fuse wire between
the alternator and the power relay behind the battery.

If that doesn't do it, check the Crank Position Sensor as someone else
suggested - they get flakey as they warm up. Another simple remove
and replace made complicated by having to reach the bolts. Those are
special shoulder bolts, BTW, so don't lose them.

--
Will Honea

A dirty or rotted ground strap will cause all of your symptoms.

The strap runs from the rear of the engine head to the firewall and
grounds the body tub.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

RAD wrote:
>
> I am in need of help with an electrical problem on my 88 Jeep Cherokee
> 4.0 L, 2wd, 5 speed standard trans., with AC. The vehicle sometimes
> will start without problem, but as soon as ANY load is put on the
> electrical system, such as brake lights, wipers, dome lights, putting
> the vehicle in gear, will stall the engine. At that point, the engine
> will not restart. There is no spark from the coil. When the engine is
> running it throws a GREAT spark. Also, when the engine is running the
> alternator does not charge.
> A new battery has been installed. A new alternator has been
> installed, a new coil and coil module has been installed. A new
> distributer cap and new plug wires have been installed. Six new
> relays have been installed and all fuses under the dash have been
> checked and/or replaced. After the coil and module were installed it
> ran GREAT for approximately 15 miles and then engine stalled,
> displaying all of the above stated problems again. I had to have the
> vehicle towed home.
> It should be noted that the only draw on the engine that does NOT
> cause it to stall is the AC. Running the AC at idle does not stall
> the engine, but if the brake pedal is depressed the engine stalls
> immediately.
> What am I missing and what do I need to do to solve the problem.
> Robert