Computer for a 94 4.0L YJ

Try these guys

Why do you think yours is dead?

Mike

Mike wrote:

That's my question too. Usually, as far as I know, these things don't go out unless water damage.

Most of the time a CPU failure is actually due to bad ground or corroded connector. But it can happen. On my ZJ the whole computer is potted in hard plastic/epoxy stuff.

and speaking of potted... I need a beer.

Hey, Mike, I know this is OT, but where in Omaha are you? I'm in Bellevue. Shoot me an email at "gymrat"@"cox.net". Take out the "s...

The engine was running real rough, so I had my friend run some tests on it and he traced the problem back to the computer( or so I hope if I buy a new one ). I guess it was only running on five cylinders.

Mike

On a 94, I would be cleaning grounds before spending money.

On my 4.2, the computer has some ground tags on the back side of the block near the oil pressure sender, think my 4.0 does too and I think yours has a computer ground on the inside of the firewall up on top of the gas pedal area.

Some YJ's also have a ground tag for the computer and fuel pump on the emergency brake pedal bracket.

These are all small black wires.

Then the main sneaky one is either the battery to the firewall at the firewall and/or there is a mesh cable from the rear of the head to the firewall. They don't 'look' dirty easily, if they look dirty, they are.

If any of these are corroded, the computer will have brain farts.

Mike

Mike wrote:

Not knowing what tests were run and how, I would be looking for a bad ingition part (plug, plug wire, cap/rotor) or a bad injector (injector itself and/or the wiring to to it) before forking out any money on the computer. Having a single performance failure in the computer is a pretty unlikely event compared to the above. Pull the plugs and identify the bad cylinder - it should be obvious from the appearance - and start from there.