I have a 88 jeep wagoneer limited. It has been running extremely rich. I have changed; o2 sensor, CPS. Anyone have any ideas what else I could check/change.

Where is the ECU located?

 

It ain't the ECU. Get that out of your head. Most likely it's a bad hose/pipe from the throttle body to the MAP sensor on the firewall.

There are also a slew of other things it could be, but the ECU is the LAST thing on the list.

 

Ok will look at that. What am I looking for to see if its bad? Cracked broke clogged?

 

Yes! It might be very brittle by the way.

 

Thanks! This thing is getting like 7miles to the gallon... Killing me

 

You would be wise to look over the Renix stuff there in Cruiser's signature, (and mine).

Yea, the MAP will dump more fuel as it senses less vacuum. (which is what happens as you put your foot in it). Blocked, cracked if off.... that little tube is crucial.

 

Cts....http://www.lunghd.com/Tech_Articles/...iagnostics.htm

 

You guys were spot on!!! Tube was cracked in the 1st bend below the sensor. Now where in the heck do you find a new pre bent tube ??? Auto parts store has just bulk vac tubing... Thanks guys.

 

Vacuum line work fine either cut in a patch.

 

Like freedgr says....I think mine is in at least three pieces spliced with small vacuum line. I carefully put a little silicone on the outside of the tube. If you are very careful not to melt it to crap, you can warm and bend that tubing with a lighter.

Idk if you can buy that actual part separate from the harness at Napa or not.

It's good to not have low spots where any liquid might settle. You want it going down all the way to the TB.

 

I haven't found anywhere that has them.

Just a quick note here. Whenever they run that rich, that hose/pipe is a prime suspect. A CTS or IAT can affect mixture as that's what they do, but NOWHERE to the extent the MAP does.

 

Thanks guys