tg22ar

Been trying to figure out WTH my rig is doing this.
New ignition switch, relays/no change.
It has a rough start intermittently too. I was thinking maybe CPS/CKS? Fuel pump ballast resistor?

My apologies for the side angle.

freegdr

Will it start in neutral ?You getting juice to starter ? NSS ?

tg22ar

I was just turning on the electric there. It gets juice to the starter. The problem is the fuel pump isn't priming and the CEL should pop up at the turn of the key to let the user know the ECU has power.

freegdr

So it starts fine ?

tg22ar

Sometimes it fires immediately(very smooth/no hesitation), then others it takes a few seconds and it bogs and runs rough, but after a few more seconds, smooth as can be.

zkdawg

I would change the pcm, my wife had one before we met and sometimes the pump would not go and they changed the pcm with one from the juck yard and it started great till that old pcm went out then they just bought a new one and it went till it was rear ended and totaled

freegdr

Key on key off method check codes . Even if lights not on .

tg22ar

Thanks for the reply. I was thinking PCM could very well be the culprit. Im going to look in the main harness and PCM for corrosion etc tonight. If not, tomorrow well be off to the yard looking for an organ donor. Its $34 for a donor unit, I will grab it off of the same xj I grabbed my cluster from.

tg22ar

Code 12 then 55.

freegdr

Try ecm then .

tg22ar

Roger that. Super busy tomorrow, going to the yard wednesday. Ill let you know what happens with the replacement unit. thanks for the input!

Radi

Code 12 means power to the ECM has been interrupted in the last 50 ignition cycles or something similar to that. Did you unhook the battery? If not you may have an intermittent wiring problem.
55 means nothing, it's the end of sequence code.

cruiser54

Pretty big jump to go right to PCM for an intermittent rough idle on starting. Just sayin'.

No diagnostics performed. Parts thrown at it. No known history of tune up parts, inspection of vacuum lines/connections or electrical connections in the engine bay.

tg22ar

You are right. But its not only the rough start. Its mainly that the CEL doesn't illuminate along with no prime until about 20-30 seconds. It should immediately light up and prime. Has. A newer tune up within the past 1000 miles. New plugs/rotor/wires. Grounds checked with meter and seem to be good.

DFlintstone

Maybe check/clean the ASD relay? I might do the battery terminals as well just on GP.