This gremlin is still eluding me!
 

I posted last week about my 97 Wrangler 4.0 AT not starting and I'm still
trouble-shooting. My current question is "what controls the fuel pump's
pressurization cycle?" On my jeep, the fuel pump is running constantly
when the ignition is in the "on" position, rather than running for a
couple of seconds to pressurize the rail. I think that if I knew what
controlled that, I might have a clue on finding my gremlin. There is no
juice on the distributor side of the coil. There is fuel pressure at the
rail. So far, I have ruled out the crank position sensor, bad ground, the
entire throttle body with all attached electrical gizmos, and I have
cleaned every electrical connection that I can readily get to under the
hood... My plan of action from here is the coil, a short somewhere in the
harness, and the PCM. Any help is appreciated.

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Re: This gremlin is still eluding me!
 

Junior Samples did pass the time by typing:
> I posted last week about my 97 Wrangler 4.0 AT not starting and I'm still
> trouble-shooting. My current question is "what controls the fuel pump's
> pressurization cycle?" On my jeep, the fuel pump is running constantly
> when the ignition is in the "on" position, rather than running for a
> couple of seconds to pressurize the rail. I think that if I knew what
> controlled that, I might have a clue on finding my gremlin. There is no
> juice on the distributor side of the coil. There is fuel pressure at the
> rail. So far, I have ruled out the crank position sensor, bad ground, the
> entire throttle body with all attached electrical gizmos, and I have
> cleaned every electrical connection that I can readily get to under the
> hood... My plan of action from here is the coil, a short somewhere in the
> harness, and the PCM. Any help is appreciated.

The pump is controlled by the computer. It should run for about two
seconds then shut off. It starts running again when the engine fires.
Sticky relay? In my Jeep it's the relay center by the battery. About a 9$
part (but the same as the fog or AC relay so they can be swapped)

If the engine doesn't crank (computer doesn't sense the motor has started)
within about two cranks it kills the engine by removing power from the ASD
relay (which depowers the coil and should also kill the fuel pump) Can't
say for certain as your wiring is different from mine.

What your describing could very well be a coil. My ZJ did that last time
the coil went south.. And even after I ohmed out the coil (which tested "ok")
the coil was still bad inside and would not throw enough of a spark.

They make a spark tester.
http://www.thetoolwarehouse.net/shop/TTW409.html

New coil is cheap enough, but I'd swap the Pump and ASD relays first.

--
DougW

Re: This gremlin is still eluding me!
 

Junior Samples did pass the time by typing:
> I posted last week about my 97 Wrangler 4.0 AT not starting and I'm still
> trouble-shooting. My current question is "what controls the fuel pump's
> pressurization cycle?" On my jeep, the fuel pump is running constantly
> when the ignition is in the "on" position, rather than running for a
> couple of seconds to pressurize the rail. I think that if I knew what
> controlled that, I might have a clue on finding my gremlin. There is no
> juice on the distributor side of the coil. There is fuel pressure at the
> rail. So far, I have ruled out the crank position sensor, bad ground, the
> entire throttle body with all attached electrical gizmos, and I have
> cleaned every electrical connection that I can readily get to under the
> hood... My plan of action from here is the coil, a short somewhere in the
> harness, and the PCM. Any help is appreciated.

The pump is controlled by the computer. It should run for about two
seconds then shut off. It starts running again when the engine fires.
Sticky relay? In my Jeep it's the relay center by the battery. About a 9$
part (but the same as the fog or AC relay so they can be swapped)

If the engine doesn't crank (computer doesn't sense the motor has started)
within about two cranks it kills the engine by removing power from the ASD
relay (which depowers the coil and should also kill the fuel pump) Can't
say for certain as your wiring is different from mine.

What your describing could very well be a coil. My ZJ did that last time
the coil went south.. And even after I ohmed out the coil (which tested "ok")
the coil was still bad inside and would not throw enough of a spark.

They make a spark tester.
http://www.thetoolwarehouse.net/shop/TTW409.html

New coil is cheap enough, but I'd swap the Pump and ASD relays first.

--
DougW

Re: This gremlin is still eluding me!
 

Junior Samples did pass the time by typing:
> I posted last week about my 97 Wrangler 4.0 AT not starting and I'm still
> trouble-shooting. My current question is "what controls the fuel pump's
> pressurization cycle?" On my jeep, the fuel pump is running constantly
> when the ignition is in the "on" position, rather than running for a
> couple of seconds to pressurize the rail. I think that if I knew what
> controlled that, I might have a clue on finding my gremlin. There is no
> juice on the distributor side of the coil. There is fuel pressure at the
> rail. So far, I have ruled out the crank position sensor, bad ground, the
> entire throttle body with all attached electrical gizmos, and I have
> cleaned every electrical connection that I can readily get to under the
> hood... My plan of action from here is the coil, a short somewhere in the
> harness, and the PCM. Any help is appreciated.

The pump is controlled by the computer. It should run for about two
seconds then shut off. It starts running again when the engine fires.
Sticky relay? In my Jeep it's the relay center by the battery. About a 9$
part (but the same as the fog or AC relay so they can be swapped)

If the engine doesn't crank (computer doesn't sense the motor has started)
within about two cranks it kills the engine by removing power from the ASD
relay (which depowers the coil and should also kill the fuel pump) Can't
say for certain as your wiring is different from mine.

What your describing could very well be a coil. My ZJ did that last time
the coil went south.. And even after I ohmed out the coil (which tested "ok")
the coil was still bad inside and would not throw enough of a spark.

They make a spark tester.
http://www.thetoolwarehouse.net/shop/TTW409.html

New coil is cheap enough, but I'd swap the Pump and ASD relays first.

--
DougW

Re: This gremlin is still eluding me!
 

An excellent suggestion but unfortunately, another thing that I've already
tried. I swapped the relays not only between the ASD and fuel pump relay
but also between my wife's 97 WJ and my TJ all to no avail. I am still
waiting for the free time to address the coil...

On Wed, 05 Jul 2006 21:05:40 -0400, DougW <post.replies@invalid.address>
wrote:

> Junior Samples did pass the time by typing:
>> I posted last week about my 97 Wrangler 4.0 AT not starting and I'm
>> still
>> trouble-shooting. My current question is "what controls the fuel pump's
>> pressurization cycle?" On my jeep, the fuel pump is running constantly
>> when the ignition is in the "on" position, rather than running for a
>> couple of seconds to pressurize the rail. I think that if I knew what
>> controlled that, I might have a clue on finding my gremlin. There is no
>> juice on the distributor side of the coil. There is fuel pressure at
>> the
>> rail. So far, I have ruled out the crank position sensor, bad ground,
>> the
>> entire throttle body with all attached electrical gizmos, and I have
>> cleaned every electrical connection that I can readily get to under the
>> hood... My plan of action from here is the coil, a short somewhere in
>> the
>> harness, and the PCM. Any help is appreciated.
>
> The pump is controlled by the computer. It should run for about two
> seconds then shut off. It starts running again when the engine fires.
> Sticky relay? In my Jeep it's the relay center by the battery. About a
> 9$
> part (but the same as the fog or AC relay so they can be swapped)
>
> If the engine doesn't crank (computer doesn't sense the motor has
> started)
> within about two cranks it kills the engine by removing power from the
> ASD
> relay (which depowers the coil and should also kill the fuel pump) Can't
> say for certain as your wiring is different from mine.
>
> What your describing could very well be a coil. My ZJ did that last time
> the coil went south.. And even after I ohmed out the coil (which tested
> "ok")
> the coil was still bad inside and would not throw enough of a spark.
>
> They make a spark tester.
> http://www.thetoolwarehouse.net/shop/TTW409.html
>
> New coil is cheap enough, but I'd swap the Pump and ASD relays first.
>



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Re: This gremlin is still eluding me!
 

An excellent suggestion but unfortunately, another thing that I've already
tried. I swapped the relays not only between the ASD and fuel pump relay
but also between my wife's 97 WJ and my TJ all to no avail. I am still
waiting for the free time to address the coil...

On Wed, 05 Jul 2006 21:05:40 -0400, DougW <post.replies@invalid.address>
wrote:

> Junior Samples did pass the time by typing:
>> I posted last week about my 97 Wrangler 4.0 AT not starting and I'm
>> still
>> trouble-shooting. My current question is "what controls the fuel pump's
>> pressurization cycle?" On my jeep, the fuel pump is running constantly
>> when the ignition is in the "on" position, rather than running for a
>> couple of seconds to pressurize the rail. I think that if I knew what
>> controlled that, I might have a clue on finding my gremlin. There is no
>> juice on the distributor side of the coil. There is fuel pressure at
>> the
>> rail. So far, I have ruled out the crank position sensor, bad ground,
>> the
>> entire throttle body with all attached electrical gizmos, and I have
>> cleaned every electrical connection that I can readily get to under the
>> hood... My plan of action from here is the coil, a short somewhere in
>> the
>> harness, and the PCM. Any help is appreciated.
>
> The pump is controlled by the computer. It should run for about two
> seconds then shut off. It starts running again when the engine fires.
> Sticky relay? In my Jeep it's the relay center by the battery. About a
> 9$
> part (but the same as the fog or AC relay so they can be swapped)
>
> If the engine doesn't crank (computer doesn't sense the motor has
> started)
> within about two cranks it kills the engine by removing power from the
> ASD
> relay (which depowers the coil and should also kill the fuel pump) Can't
> say for certain as your wiring is different from mine.
>
> What your describing could very well be a coil. My ZJ did that last time
> the coil went south.. And even after I ohmed out the coil (which tested
> "ok")
> the coil was still bad inside and would not throw enough of a spark.
>
> They make a spark tester.
> http://www.thetoolwarehouse.net/shop/TTW409.html
>
> New coil is cheap enough, but I'd swap the Pump and ASD relays first.
>



--
Using Opera's revolutionary e-mail client: http://www.opera.com/mail/

Re: This gremlin is still eluding me!
 

An excellent suggestion but unfortunately, another thing that I've already
tried. I swapped the relays not only between the ASD and fuel pump relay
but also between my wife's 97 WJ and my TJ all to no avail. I am still
waiting for the free time to address the coil...

On Wed, 05 Jul 2006 21:05:40 -0400, DougW <post.replies@invalid.address>
wrote:

> Junior Samples did pass the time by typing:
>> I posted last week about my 97 Wrangler 4.0 AT not starting and I'm
>> still
>> trouble-shooting. My current question is "what controls the fuel pump's
>> pressurization cycle?" On my jeep, the fuel pump is running constantly
>> when the ignition is in the "on" position, rather than running for a
>> couple of seconds to pressurize the rail. I think that if I knew what
>> controlled that, I might have a clue on finding my gremlin. There is no
>> juice on the distributor side of the coil. There is fuel pressure at
>> the
>> rail. So far, I have ruled out the crank position sensor, bad ground,
>> the
>> entire throttle body with all attached electrical gizmos, and I have
>> cleaned every electrical connection that I can readily get to under the
>> hood... My plan of action from here is the coil, a short somewhere in
>> the
>> harness, and the PCM. Any help is appreciated.
>
> The pump is controlled by the computer. It should run for about two
> seconds then shut off. It starts running again when the engine fires.
> Sticky relay? In my Jeep it's the relay center by the battery. About a
> 9$
> part (but the same as the fog or AC relay so they can be swapped)
>
> If the engine doesn't crank (computer doesn't sense the motor has
> started)
> within about two cranks it kills the engine by removing power from the
> ASD
> relay (which depowers the coil and should also kill the fuel pump) Can't
> say for certain as your wiring is different from mine.
>
> What your describing could very well be a coil. My ZJ did that last time
> the coil went south.. And even after I ohmed out the coil (which tested
> "ok")
> the coil was still bad inside and would not throw enough of a spark.
>
> They make a spark tester.
> http://www.thetoolwarehouse.net/shop/TTW409.html
>
> New coil is cheap enough, but I'd swap the Pump and ASD relays first.
>



--
Using Opera's revolutionary e-mail client: http://www.opera.com/mail/

Re: This gremlin is still eluding me!
 

Junior Samples did pass the time by typing:
> An excellent suggestion but unfortunately, another thing that I've already
> tried. I swapped the relays not only between the ASD and fuel pump relay
> but also between my wife's 97 WJ and my TJ all to no avail. I am still
> waiting for the free time to address the coil...

When you do the coil (if you do the coil) make sure you get the upgraded
part. Napa has it (and the OEM part is from the same folks)
You will know the part because it comes with a voltage reducing adapter cable.

ECHIC409 is the part number. It's not cheap $50 (dang thing went up 10$ since I
got mine last year!) If your retired/active duty/civillian napa has a good
discount program. Pays to ask. Jeep had a recall on the ignition coil long
time ago and this was the part they used.

--
DougW

Re: This gremlin is still eluding me!
 

Junior Samples did pass the time by typing:
> An excellent suggestion but unfortunately, another thing that I've already
> tried. I swapped the relays not only between the ASD and fuel pump relay
> but also between my wife's 97 WJ and my TJ all to no avail. I am still
> waiting for the free time to address the coil...

When you do the coil (if you do the coil) make sure you get the upgraded
part. Napa has it (and the OEM part is from the same folks)
You will know the part because it comes with a voltage reducing adapter cable.

ECHIC409 is the part number. It's not cheap $50 (dang thing went up 10$ since I
got mine last year!) If your retired/active duty/civillian napa has a good
discount program. Pays to ask. Jeep had a recall on the ignition coil long
time ago and this was the part they used.

--
DougW

Re: This gremlin is still eluding me!
 

Junior Samples did pass the time by typing:
> An excellent suggestion but unfortunately, another thing that I've already
> tried. I swapped the relays not only between the ASD and fuel pump relay
> but also between my wife's 97 WJ and my TJ all to no avail. I am still
> waiting for the free time to address the coil...

When you do the coil (if you do the coil) make sure you get the upgraded
part. Napa has it (and the OEM part is from the same folks)
You will know the part because it comes with a voltage reducing adapter cable.

ECHIC409 is the part number. It's not cheap $50 (dang thing went up 10$ since I
got mine last year!) If your retired/active duty/civillian napa has a good
discount program. Pays to ask. Jeep had a recall on the ignition coil long
time ago and this was the part they used.

--
DougW