Raw fuel in exhaust pipe drivers side…xjs '89 (Lucas ignition)
What is problem ??
thanks, Sloth
Fuel? Are you sure?
If indeed fuel is “pooring out of the exhaust”, the entire bank must be dead and not firing AT ALL, which should be impossible on a LUCAS CEI…
Others with hands-on-knowledge on Lucas-ignition should chime in.
Steve
Sloth, You should check for spark on several plugs on the B bank (driver) side as the first step. If spark on several, then check all plugs for spark on B bank. If all have a bright blue spark on all, you may have one or more injectors stuck open. Check spark as the first order of diagnosing, and report back. SD Faircloth
Thanks for the data on spark could be the problem…I will check that
shortly…
But some-one else said check relay at ECU which could control all
injectors for the B bank.thus leaving them open…(it is worth a try)
I disagree, anything is possible. 
What if the spark plug wires were removed and improperly installed. This engine could then have good fuel pressure, good fuel injectors, and good ignition but if the spark was happening at the wrong time I believe fuel would pass out of the engine (especially a cold engine) through the exhaust system and out the tail pipe.
Regards,
Paul M. Novak
1990 Series III V12 Vanden Plas
1990 XJ-S Classic Collection convertible
1987 XJ6 Vanden Plas
1984 XJ6 Vanden Plas
1969 E-Type FHC
1957 MK VIII Saloon
Ramona, CA USA
Sloth,
Check that the fuel injectors are all making a clicking sound (I use a mechanics stethoscope when checking this) and that the B side fuel regulator is holding vacuum. You could have stuck fuel injectors putting more fuel into the engine than can be burned, or a leaking fuel pressure regulator putting more fuel into that bank than can be burned. Another possibility is that the spark plug wires were removed and improperly replaced so that even though there is fuel and spark it isn’t being burned because the spark is happening at the wrong time.
Regards,
Paul M. Novak
1990 Series III V12 Vanden Plas
1990 XJ-S Classic Collection convertible
1987 XJ6 Vanden Plas
1984 XJ6 Vanden Plas
1969 E-Type FHC
1957 MK VIII Saloon
Ramona, CA USA
Hi: I did change plugs and wires all were running smoothly for about a month…I did it very carefully and I believe done right…thanks… Sloth
Are you suggesting that all leads were installed wrong?
While possible, this is highly unlikely.
For raw fuel to come out of the exhaust pipe as a liquid, one needs to have a massive fueling problem.
I don’t think it could be a misfire or stuck injector on a cylinder or two.
Steve
Vacuum feed to fuel pressure regulator could suck raw fuel in huge quantity if diaphram is ruptured.
Hello Ivan, I’ve been away from the forum for a couple of days putting new springs on my car, but I did read your other post.You say that your car somehow emptied its gas tank and was completely dry. Then you put fuel in and it started. You don’t say how well (or badly) it ran, which would be a good clue.Have you looked in your trunk in case there is simply a gas leak and fuel is dripping on to your exhaust ? Have you pulled the engine dipstick to see if your oil level has magically increased? That is the first thing I would suggest you check. Oil diluted with gasoline is not good for your engine’s life! Baxtor’s suggestion is a good one, too
Dave, Baxtor. Sloth… A rupture of the B bank FPR diaphragm can be easily diagnosed. Just pull off the rubber vacuum hose from the nipple on the front of the B Bank intake manifold that leads/connects to the B bank FPR. If the hose drips or pours fuel, the diaphragm is ruptured, and the FPR needs to be replaced. SD Faircloth
Hi Dave: I have been busy too…here’s some new news…I found this regulator on my work bench…I cannot remember taking it off plus…or where it should be returned…
I keep looking for an opening and still cannot find one…Please identify it for me (if you can) and give me a clue to where it belongs…
P.S don’t tell anyone how stupid I am.
Regards
Ivan
Hi Dave:
This may solve my problem…I found a pressure device on my work
bench…I do not remember taking it off or where it goes…
I took a picture and I cannot send it through the Jag site. Send me your
e-mail address and I am sure I can send it as a new message…
Thanks,
Ivan (sloth)
Sloth,
That part looks like a Transmission Vacuum Modulator, Jaguar Part Number EAC1726, located on the right side of the automatic transmission as accessed from beneath the car. A vacuum line goes from the modulator to the rear of the right (A Bank) side intake manifold on my wife’s 1990 XJ-S convertible (5.3L V12 w/ Marelli ignition).
Regards,
Paul M. Novak
1990 Series III V12 Vanden Plas
1990 XJ-S Classic Collection convertible
1987 XJ6 Vanden Plas
1984 XJ6 Vanden Plas
1969 E-Type FHC
1957 MK VIII Saloon
Ramona, CA USA
Vacuum regulator for transmission.(pictured)…SD, Limey and Baxtor are on the trail. Any fuel lines not connected or burned through as it ran? …sooooooooooooooooooo, Best, JW
Ivan, Paul and JW are right- its a vacuum modulator. Not going to help. Have you checked your engine oil level yet?. How does the engine seem to run ? Any more clues- there’s not much to work with here. I did send the address.
Hi Dave:
It took me forever to transfer the picture properly…it looks like it is
not my problem…checked the oil level a trifle higher but it could have
been me overfilling…
I will give it another try at smooth running and get back to you…
Regards
Ivan
Hi Dave:
I plan on starting the car tomorrow; but I would like to check the injectors first…upon removing the plug…if I put 12 volts to either of the terminals should I hear a click ??
Thanks, Ivan
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