Hi Guys,

I have a bone stock, 2000 Cherokee that has had a history of misfire codes when above 65 degrees / fuel vapor issues after hot restarts, a few days ago, it just decided to stop at a light, restarted a couple of times, but was shaking and making a racket, smoke from the passenger side of the engine compartment and then ended up having to be towed home, since then I have done the following:

Checked fuel pressure with a gauge on the shraeder valve on the fuel rail.
Checked voltage to the fuel injectors while cranking. Close to 12v
Checked resistance on the fuel injectors themselves. Within the specs.
Checked for spark on all plugs. All checked out good.
Checked relays, fuel pump, etc. Didnt find any issues here.
Checked the Crank Angle and the Can Position Sensor.

The only code I am getting when its not showing any is a TPS / APP Low circuit and I am unsure if this would be enough to prevent starting. The tank was full of gas.
If anyone has any suggestions, I would love to hear them. At a bit of a dead end. The only thing I can think of is a compression test? It operates momentarily on starting fluid, but not enough to take over on its own afterwards. I am still leaning towards a fuel issue and treated the tank with iso-heet thinking that perhaps it had some water in the tank. Next step is to drain and refill but that would seem a bit extreme, the fuel that has come out of the tank seems to be fine, smells fine, burns like normal fuel when lit.

Thank you for your time

 

That condition without throwing a code that could explain either fuel or ignition problems could mean a failing computer.

 

Check the fuel pressure while cranking. you may have a plugged fuel filter. Also a collapsed matrix in the downstream converter. Just a guess.