1985 xjsc, 3.6l and 5spd imported from Canada won't stay running. will start and run poorly for about 5 seconds then die. If I disable fuel pump it will start and run ok for about 5 seconds.Car sat for many years before I purchased it.while trying to start it it dumped maybe 1.5 gallons of gas into the oil.Have drained all that and repaired crushed fuel return line. Any suggestions?

 

I have a large amount of gasoline mixed with my oil in the sump. 1985 XJSC 3.6 and manual trans. Car was imported from Canada

 

Hi sandyandherman,

Welcome to the Jaguar Forums! It's great to have you with us.

I have moved your posts from the forums for the XJ40 and the New Member Area to the forum for the XJS. Here you will find knowledgeable owners of similar cars. I have also retitled your thread to encompass both issues, since they may be related.

Just thinking out loud, the crushed fuel return line would lead to excessive fuel pressure, which could lead to overfueling, which would cause rich running, and lead to unburned fuel being blown past the piston rings into the crankcase. This could also have the effect of washing the oil from the cylinders, reducing compression and causing the engine to run even worse.

Are you certain all of the gasoline you found in the crankcase was due to your starting attempts, or could some of it have gotten there during the previous owner's starting attempts?

Cheers,

Don

 

Normally, fuel in the oil in large quantities indicates an injector which is always open, normally in the V12 because the injector loom has deteriorated and is shorting to earth.
If the 3.6 has a similar system, then that is your prime suspect.

 

Could be a fuel pressure regulator problem, causing overfuelling.

 

With the fuel pump circuit energized there should be a pretty audible whir from the regulator as it allows fuel to flow by. Not very scientific but at least is a yes/no on whether it is allowing any fuel past at all.

Easiest DIY injector check (IMO) is to just pull one of the injectors and crank it over, see if it's pulsing or just staying on.

 

I think I figured out the problem, FPR was bad but I discovered a new issue; no vacuum at Engine Control Module in trunk (boot). I put a vacuum to it and car runs much better, but I can't find where line terminates in engine compartment. This is a 3.6l straight six.Any help would be appreciated. I was able to confirm no stuck injectors. Thank you all for the help, was making me crazy but think I am on the right path now as car had multiple issues.

 

The vac line to the ECU terminates under the wooden toe board at the forward end of the passenger footwell, where the ECU is sited on 3,6 litre cars. Lift the carpet and you will find it.