After being down for a few months getting a new radiator, cooling system makeover (electrics replacing the engine-driven fan, new wing tank, hoses, thermostats, heater valve, engine mounts, ceramic coating the exhaust manifolds, lots of bead-blasting and paint, and more stuff than I can remember at the moment) kitty went on a 400 mile trip (200 nonstop miles each day) this weekend. Not being a mechanic by any means, and having done all this work myself, I was delighted that it just got us there and back with no significant issues...that is, no breakdowns. There are some things that need attention though...

1. I wasn't surprised to see the windshield leak just above my face since it's done that in the car wash. More surprising was feeling water drip onto my right foot as it was on the accelerator pedal. Has anyone had experience with this? I suppose with a hose and several hours on my hands I might be able to determine where this water is coming from, any help would be appreciated.

2. Gas mileage was not good...11 MPG for the trip. Some of that may be my fault :-), since I removed the RH fuel regulator because it was leaking, and per Palm the RH regulator supposedly does little or nothing anyway. Having said that, today I put an air-fuel meter on it, and it indicates that the engine is running pretty rich.

I've purchased a specific regulator for this car to replace the RH one, and it seems to have had problems all its own. I guess I could try again, but I'm wondering if there isn't some more generic (cheaper) regulators that I can put on it rather than "experimenting" at $100 a pop for the OEM stuff just hoping that it works.

Thanks!

John
1987 XJ-S V12, 63,000 miles

 

I had a leaky windshield on my XJS. You could watch the water come in, as you say :-)
A new sealing rubber fixed it.

Mine leaked at the botom and water would indeed migrate down and drip on my feet.

Other sources of wet feet are plugged a/c drains and plugged inlet plenum drains...both of which allow water to pool inside the a/c unit and then overflow onto your feet....especially on turns :-)





Absence of the inlet regulator isn't the problem. Many have dumped it with no ill results. I dumped mine and usually got about 19-21 mpg from my V12 at highway speeds.

A bum outlet regulator could cause excessive pressure and overfuling....or it might be leaking and allowing raw fuel to be drawn into the engine via the vacuum hose. Check the vac hose, by the way. Is it plugged in?

One or both of your enrichment switches could cause an overfueling problem.

A skewed temp sensor can cause overfueling problem

I've heard of a couple case where injector harnesses ground-out causing and injector or two to stay "on". This would really dump in lots of extra fuel.

Cheers
DD

 

Hi Doug,

The reason I took the inlet reg off was because it started leaking fuel into the vacuum line, so that was one of the first things I checked, and it's not putting fuel into the vacuum line. But of course it could also not be responding to vacuum changes at all...is there a way to test that without buying test equipment?

I just rebuilt the injector harness last fall, but it's worth a look again. Concerning the temp sensors, looks like I can check them with a VOM at various temps and see if they are close to the values in the engine setup guide.

In any case I'm leaning towards replacing the outlet regulator with something more inexpensive. Shouldn't just about any vacuum controlled adjustable regulator work?

Thanks again!

John
1987 XJ-S V12