Jeep Commando

I have a 90' Renix, just did the headgasket and all other gaskets, most of the vaccuum lines, O2 sensor and I swapped in some Chevy "M" injectors that I had laying around (19lb).. Cant find any vaccuum leaks, all injectors are firing(not stuck open), cleaned the intake manifold and throttle body before re-assembling the motor. New plugs wires cap and rotor. At idle fuel pressure is 35psi with the regulator hooked up, with the vaccuum line off it goes to 39psi. Its supposed to be 31/39 but I dont think the 4psi difference is making it run like dog crap all across the rpm range and have black/soot exhuast. Any ideas fellas?

Gee oh Dee

Try your original injectors once.

Jeep Commando

I was thinking that but they flow the same and the GM ones have a better pintle/spray pattern (4 hole) and from what Ive read theyre the same for flow rate.. Ill give it a shot in about an our or so.. Should I check anything else in the meantime?

Gee oh Dee

What brand o2 sensor?

Jeep Commando

Bosch

Gee oh Dee

I think I have heard poor things about bosh o2s. Search to confirm, though. I could be wrong.

Jeep Commando

Edit: Gonna try a Denso O2

Jeep Commando

Well I seem to have lost 2 of the original injectors and 1 of the 4 I have has a broken connector.. Theres just no winning.. Gonna try a few more things while I can, will post later. Thanks for the help so far Gee Oh Dee

Jeep Commando

More info, hooked up a diagnostic tool, got some info. While running the MAP is at 4.8 volts and the manifold vaccuum reading is at 0. The vaccuum line at the throttle body doesnt seem right, its very loose, not sure how to fix this, maybe some goop?

Gee oh Dee

Replace the line or get a section of tube that will have the same ID.

Someone recently posted about a similar issue. Pics and all.

goneboating06

Yeah check or replace that vac line that goes to your map sensor. You should be reading about 1.5-2 Volts idling at operating temp. Without the map sensor working correctly it will run rough and very rich.

chuckanut

Which hole is the vac line that hooks to your throttle body connected to? Top or bottom? Mine was connected to top, moved it to bottom and ran MUCH better

Jeep Commando

Sealed the line, everything is mint now, nothing happened when I sprayed the lines with carb clean so I didnt think they were leaking, I unpluggled the MAP sensor and when I did that the line slid out of that rubber grommet on the throttle body which threw up the white flag of WTFs haha

Appreciate all the assistance gentlemen. Now I just gotta get a hold of Quadratec again cause they messed up my order for a second time

Jeep Commando

Pretty sure its on the bottom.