I’m reposting this as I put it in the wrong form, hope this is correct.
1981 Sovereign 84000 miles, 4.0 I believe auto magic, very clean on fault on VC 37, motto serious? Anything I should really be on the look out for. Thanks

Almost too clean to believe. Dealer say sit was not detailed.

Would have to change the fog light covers.

 

Sorry

 

Fuel Fail 37 on the VCM is the EGR circuit fault. (vacuum actuator fault?)

Please find and download S_91 4.0 Engine Management .pdf

I sent it to GUS a dozen years ago so I know he has it and should be listed on his site.

File is about 14mb and might not fit on this post.

 

Could be as simple as a bad Egr valve diaphragm, or a leak in the vac line to the manifold. Both mine use a Rochester (GM) egr valve, not hard to find if needed.

 

A leak in the EGR valve diaphragm would likely trigger a FF39 because the temp sensor would not see a temp increase at the manifold port.
FF 37 is the vacuum actuator side of things.

 

I was looking for I guess it’s a jag service bulletin you mention. I’m I looking for the right thing.?

 

I got it. Thanks

 

Jaguar Publication S_91 4.0 Engine Management is not a TSB but a .pdf of the Diagnostic Guide paper version I got almost 30 years ago.