Join Date: Apr 2002
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4.2 to 4.0 swap almost done; starts but shuts down
OK, it's been awhile since I've been here, when did this new software show up? And why did I have to register again? grrr.... But then I didn't like the old format anyway, maybe now I'll visit more often.
Nevermind that [img]images/icons/wink.gif[/img]
Here's the issue with my buddy's swap:
A buddy just swapped his 4.2 in a '79 CJ for a 4.0 from a '94 GC. Computer is wired
in, O2 sensor, CPS on new damper. Fuel pressure is correct. Engine starts, runs for
2 seconds, then shuts down. Adding fuel to the throttle body will keep it running. It
seems that the injectors are shutting down from the ASD relay.
The VSS is not hooked up, we think it should stay running without the VSS.
The other thing is that when he heard this engine run at the boneyard, it did the
same thing while still in the GC. The guy said it was the Sentry Key, he had to lock
then unlock the door with the key, then the engine ran fine.
So, if it's not the VSS, is it this sentry key crap? Any ideas on how to get around
that? I've heard one recommendation to dump the GC computer for an XJ or YJ computer, the pre-OBDII computers should be the same except for the sentry key stuff. Is the sentry key only on the GC? Is there any way around it?