Hey guys, my XJS is my daily, and it's been a damn good one so far. Today was a bit of a hiccup though. I went to start the car, it did so beautifully, but then promptly died. The second time I started it started, stalled, caught itself, stalled again and continued to repeat this pattern. The third time starting it I held the gas pedal slightly for about 20 seconds and then it maintained its idle. During the drive to work however it bucked a bit, as if it was running out of gas. IT would lose power for about a second and then pick back up. it did this twice during my 40 minute drive. Could it be the AAV? I know mine is bad, but it's never given me trouble in the summer. It was bout 64 degrees F this morning. My other guess would be O2 sensors? anything else I should check? Thanks so much.

 

AAV, yes.

Even when the engine is warmed up, and the AAV is not 100% closed, the running will suffer due to the vac leak that the ECU will sense.

Throttle discs in both throttle bodies are gunked up, very common. Most of us know this as the "black goo", and a solvent soaked rag easily wipes it clean.

Fuel pump is getting tired.

Being a 1983, it most likely has the 6CU fueling ECU, and they have issues with the fuel pump earth circuitry. Thats the Orange wire from the fuel pump relay.

Fuel filter is clogged.

TPS is going AWOL.

EFI loom in the bottom of the "V" is starting to suffer from the heat. Very common now its older.

Thats just the common stuff I can think of quickly.

 

Just FYI, the later 16CU ECU will go straight in in place of your 6CU and it is much more reliable, if that turns out to be the problem.
Greg