Hello all, I'm new here, first Jaguar- Many German cars to this point though. Have a bit of a problem.
1990 XJS V12 Won't start- It will crank, New fuel pump and filter, pump is running and have pressure at rail. Noid lights on injectors show them firing, and have good spark. Spraying starting fluid in the intakes gets me running, but just barely, won't stay running and might last 30 seconds of barely staying alive.
I don't have tach at all, even when It's firing. Does that point to a Crank Position sensor? I'd think if I didn't have CPS I wouldn't have injectors.


I also have these wires that were chewed by a mouse- would that be the crank position sensor wire in a 1-1000 shot? Only reason I ask is it's shielded.
Thanks!

 

Update- Those wires are O2 Sensor on that side and have been repaired- no change in running.

 

Sounds like you have no fuel pressure, check your fuel pump.

 

Have 30 PSI at the rails. Bringing the car back to life, the fuel in it wasn't great. thinking I'm going to have the injectors cleaned and tested

 

Has it run correctly since you got it? If not, injectors are likely stuck. See the video below on how to get them to free up, starting at about 13:40. You can tap on them at the same time with a screwdriver handle. I've seen this work on Jags, Mercedes, and other cars. The noid says it's getting a signal, but that doesn't mean it's working.

 

Yep,

Crappy fuel, 99% the cause of any engine doing what you describe.

Like the video, I use a small "tack hammer" and tap away, never had a professional clean in 50 years. Benn doing that since before WWW was invented.

Once its sort of running, a HEAVY dose of Injector Cleaner in 20ltrs of GOOD gas, and run it, then run it some more.

 

Thank you, that cleared it right up. Had 8 stuck ones, fired right up after that. Decent amount of smoke from 15 years of oil leaking on exhaust, but it runs on all 12 now. Going to toss some injector cleaner in and start chasing down the dozens of other odd problems I have. No tach, no speedo, get coolant completely topped up and solve a few squeaky belts. I appreciate the input!

 

Good to hear that you got it running! The cooling system is super critical, take the time to go through it properly.

 

SIMPLE cars these V12 Jags.

Now the fun starts.

Replace ALL the fuel hoses, V12 engine fires are SCARY.
Replace ALL the coolant hoses, that will test you.
Replace ALL the belts.
Drain and refresh ALL the fluids, another testing time.

After 15 years, this is more important than speedo, tacho etc.

 

Great! Glad to hear it worked.