Jeep YJ with 5.2l running way too rich + smoke coming out the exhaust

leakedd

leakedd

Mall Crawlin'
Joined
Jan 25, 2014
Location
Charlotte
I swapped a 5.2l into my YJ a few months ago and its been running very rich to the point where smoke is coming out the exhaust at idle and whenever I stomp the gas while driving small black clouds come out the exhaust.

I've changed o2, map, IAC, IAT sensors. Swapped PCM. Changed spark plugs. Injectors sound fine through a stethoscope (maybe one is constantly leaking???) and many other things. More detailed info on what all I've done and checked can be found in my build thread.
The Magnum YJ

I changed the oil a few days ago because you could smell a lot of gas in it and I didn't want to ruin the bearings.

I've also done a compression test on all the cylinders. The lowest one was 140 and all the others were 150-170. Also did an engine block test and it passed. So I'm pretty sure the head gaskets are good.

it also starts to misfire quite a bit once its warmed up
 
Last edited:
Fabrik8 said:
Read any trouble codes? Do you have a working obd port?

Has it done this as soon as it was swapped, or just recently?
Click to expand...
It's OBD1 and the only codes I am now getting are 33, 32 and 31. Which is A/C, EGR (swapped to a non egr intake) and EVAP, I don't have the charcoal canister installed.

I've noticed it has always smoked just a little bit ever since I first got the engine running. However the black smoke when I stomp the gas is new. And it seems to be smoking much more than it originally was.
 
Also are fuel injectors supposed to fire with just the key on? Or are they only supposed to fire when the engine it's self is rotating?

If I leave my key forward and disconnect and reconnect the battery the fuel injectors fire. So if I keep turning key off and on i'll flood the engine. And all 8 fire at the same time??

Maybe there's a chance I switched up some wires when wiring up the harness?
 
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