Hi guys, first post as im kind of chasing my tail it seems. Bought a 96 xj, that was throwing codes for o2 sensors, and had a cracked exhaust header. I replaced the header, motor mounts, o2 sensors, thermostat, coolant temp sensor, (aux fan wasnt kicking on at temp, now it does) and Initially after the manifold was replaced it ran really well, now about a week later it wont start without starter fluid and when it does the engine stumbles as if its going to stall




and the intake is sucking really loudly as if there is a vacuum leak and then revs up and then back down to 700ish and will drive great, I just dont want to start replacing random sensors or do the “parts cannon” approach. I replaced the Intake manifold temp sensor after this code and it got worse. If anyone has had a similar issue or any insight Id be very appreciative!
Thanks guys,
geoff

 

What brand of parts did you put in?
Whats your fuel pressure at KOEO? At idle?

 

I would use your OBD tool to read manifold vacuum pressure, or if it wont attach a vacuum gauge.

That should tell you if you have a leak happening, presumably you have sprayed engine start fluid around the inlet manifold, it can be mislocated, some hose may be leaking etc etc

Once you are fully satisfied there is no air leak, you can move onto other possibilities. Hissing suggests a leak