Fuel pump is powered up on key up, then processor keeps fuel pump
running as long as it sees the PIP signal from the distributor. Check
your injectors to see if they are firing with a noid light...if they
are, then you have a good PIP signal. If they fade out, then you are
losing the PIP (Profile Ignition Pickup) and that can also turn off the
fuel pump. Possible processor or relay concern, or wiring.

 

I know this thread is over 7 months old, but just for anyone else who
might be looking for the answer, here goes.. The PCM (computer) you
are using has the SKIM (Sentry Key Imobilizer Module) active. This
shuts down the engine after 5 to 10 seconds of running. Best solution
is to get a new PCM. Also, check out
http://www.cjoffroad.com/forums/ for 4.0L swap info.

-Brent Bogrees
'89 YJ 4.0L w/ 33" BFG MT's
'94 XJ 4.0L w/ 31" BFG AT's
http://www.chrr.ohio-state.edu/~bogrees/html/Jeep.html


> I have finally gotten my shiny (not really) 4.0L engine in my 89 YJ. It
> turns over and trys to start, it runs for about 5 - 10 seconds and dies.
> It feels to me like a timing issue, or power is getting cut after that
> time period. I'm out of ideas. Does anyone out there who knows their
> 4.0 well have any ideas? I'm using the computer and wiring harness from
> the donor YJ, and I'm using a CPS conversion kit that mounts the sensor
> up front. I suppose the other option could be the computer is flaky, I
> hope that is not the case.

 

I know this thread is over 7 months old, but just for anyone else who
might be looking for the answer, here goes.. The PCM (computer) you
are using has the SKIM (Sentry Key Imobilizer Module) active. This
shuts down the engine after 5 to 10 seconds of running. Best solution
is to get a new PCM. Also, check out
http://www.cjoffroad.com/forums/ for 4.0L swap info.

-Brent Bogrees
'89 YJ 4.0L w/ 33" BFG MT's
'94 XJ 4.0L w/ 31" BFG AT's
http://www.chrr.ohio-state.edu/~bogrees/html/Jeep.html


> I have finally gotten my shiny (not really) 4.0L engine in my 89 YJ. It
> turns over and trys to start, it runs for about 5 - 10 seconds and dies.
> It feels to me like a timing issue, or power is getting cut after that
> time period. I'm out of ideas. Does anyone out there who knows their
> 4.0 well have any ideas? I'm using the computer and wiring harness from
> the donor YJ, and I'm using a CPS conversion kit that mounts the sensor
> up front. I suppose the other option could be the computer is flaky, I
> hope that is not the case.

 

I know this thread is over 7 months old, but just for anyone else who
might be looking for the answer, here goes.. The PCM (computer) you
are using has the SKIM (Sentry Key Imobilizer Module) active. This
shuts down the engine after 5 to 10 seconds of running. Best solution
is to get a new PCM. Also, check out
http://www.cjoffroad.com/forums/ for 4.0L swap info.

-Brent Bogrees
'89 YJ 4.0L w/ 33" BFG MT's
'94 XJ 4.0L w/ 31" BFG AT's
http://www.chrr.ohio-state.edu/~bogrees/html/Jeep.html


> I have finally gotten my shiny (not really) 4.0L engine in my 89 YJ. It
> turns over and trys to start, it runs for about 5 - 10 seconds and dies.
> It feels to me like a timing issue, or power is getting cut after that
> time period. I'm out of ideas. Does anyone out there who knows their
> 4.0 well have any ideas? I'm using the computer and wiring harness from
> the donor YJ, and I'm using a CPS conversion kit that mounts the sensor
> up front. I suppose the other option could be the computer is flaky, I
> hope that is not the case.