Jeep Garage  - Jeep Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
I couldn't lie used engine in my 98 Grand Cherokee hooked everything up and there is getting no fuel I pulled the relay and can jump a wire across and it starts right up I have checked and replace the fuel relay I have checked and replace the automatic shutoff relay anybody have any suggestions I sure could use it it runs great if I jump the wire so I know the fuel pumps good and everything else just why isn't that relay getting kicked on
 

·
Registered
Joined
·
475 Posts
Welcome to the Forum, from Cave Creek AZ.
 

·
Registered
2015 WK2 Overland
Joined
·
1,821 Posts
Electrical problems suck. Have you checked to make sure all grounds are connected? How about testing continuity back to the ECU (I assume the relay trigger goes to the ECU). Does the ECU attempt to trigger the fuel pump?

Some extra leads and a multimeter will be your best friend.
 

·
Registered
Joined
·
2,328 Posts
OK lets do some brain storming whether ridiculous, laughable or thought provoking.

I'll 2nd what IAmTodd said, make sure all the grounds are there and corrosion free.

Then i'd re-seat any connectors at the relay box and PCM. IMPORTANT! make sure you disconnect the battery first.

From what you've said it could be the fuel relay's energizing coil is not getting voltage to operate the relay.
Since you replaced both the fuel and ASD relays, look carefully into their sockets for spread or corroded pins if not done already.

You seem to know enough to jumper the fuel relay so i'd figure out a way to check the fuel relay's coil pins to make sure its getting 12 volts. If not its a matter of tracing back to find out why.
The ASD relay could be the root cause so check its relay coil's voltage also.

There might also be a fuse blown. Have you checked them?

Finally and its a stretch but there's a remote possibility the replacement engine or cabling is for some reason not compatible with your PCM and/or relay box but i highly doubt thats the case.
Is the replacement engine the same year as your Jeep?
Did you get the used engine from a junk yard and if so did you use some of its old cabling?

Hope you have some good electrical diagrams.
 

·
Registered
Joined
·
2 Posts
The ZJ pcms have a problem with broken solder connections. I had to repair mine. Look up the fix on re-soldering a ZJ pcm.
 

·
Registered
Joined
·
9 Posts
Correct me if I'm wrong. Doesnt the factory secuirty cut out cut off the fuel pump? Or does it kill crank. I can't remember I know I tried to bypass and remove mine and locked it up and my jeep wouldn't start. But I cant remember if it cranked or just cut fuel and crank no started. Could be a security issue.
 
1 - 7 of 7 Posts
Top