Join Date: Jul 2009
Location: Northern California
CJ7 w/Howell Running rich and rough
I have a 1985 CJ7 258 4.2L that I installed a Howell fuel injection California model on. I also installed a Borla header. When I start the jeep it runs rough and will barely idle. It is running very rich (the plugs are black). Howell is closed on the weekends so I can't call them. Check engine light shows code 33.
Here is what I have checked so far: Fuel pressure is 13 to 13.5 psi. O2 sensor checked with volt meter readings were .9V DC when heat applied and dropped to .1V DC when heat removed. Map sensor checked and reads 4.85 volts and drops 1 volt for every 5 inch Hg added with a vacuum pump. Replaced cap, rotor, plugs, wires and checked timing which was about 5* BTDC. All vacuum lines have been replaced with new lines. Anyway, I don't know what else to check and would appreciate any help or feedback anyone might have.
Last edited by fastener; 12-01-2012 at 08:57 PM.