It appears that my oil pressure gauge is reading inversely. When engine is cold it will read about 50 at idle. After warm it will read 80. Increasing rpm's will decrease oil pressure. Can someone tell me how the sender should be wired? Measuring from sender wire to case I read 7.5V and the gauge is around 60. I want to hook up an external mechanical gauge to see what it says, but I'm having difficulty finding an accessible oil gally port.

 

Not much to tell. It's just a single white/brown wire to the pressure sender.

(not to be confused with the black/brown wire going to the pressure switch for the warning light)


Disconnect the wire to the sender. Turn key on. Oil gauge should be at zero. Now touch the wire to ground. The gauge should go right to the top. Assuming it does, that leaves a faulty sender or a wiring problem as the possible culprits. From your description of the problem my money's on the sender.

Cheers
DD

 

The oil gauge sender works in reverse.

Most gauge senders are 0.00 Ohms at rest, and up to about 600 for 80psi.

The Smiths Jag unit is 600ish Ohms at rest and moves towards Zero as pressure rises.

NO IDEA why, its a Jag.

Afternarket senders can be fitted, but their scale is the wrong way, and that is what I reckon is in yours.

Being a Carby car, there will be a 2nd oil Switch behind the oil filter housing, usually, that is also reverse contact, and is used to earth the fuel pump relay, but it is only an ON/OFF switch, not scaled in any way.

There are 1/2" UNF threaded ports along the RH side of that engine, that are direct into the oil gallery, some are easy to get at, some not so. There is one under the power steer pump bracket that is easier that others. Towards the rear the starter motor is in the way from memory.

 

Then I read your list of cars, OOPS.

Is this the V8 conversion????

If so, forget most of the above.

You will need a Jag Oil Gauge Sender unit to operate the Jag dash gauge, for the reverse Ohnm reasons I stated above.

NO idea on oil gallery access on a Chev, sorry for the screw up. I need Coffee me thinks.

 

Yes its the 350 conversion. Sounds like Ill need to get the correct sender. I still plan on checking it with a mechanical gauge though. Can I assume that the little red light on the dash witch currently isn't connected was originally used to indicate high pressure?

 

Heh heh, I wasn't paying attention myself. My mind picked up the "84" in IndyJag's screen name as '1984' Jaguar.

I think the wire colors are the same, though


Cheers
DD

 

Doug,
I created my screen name before I purchased this car, I was originally looking at an 84. And yes the signal wire is white/brown.

 

Thank you for that.

The Jag engines ran 2 sender units. 3 in some cases.

The one we talked of for the gauge.

The 2nd is a standard Idiot light switch, and is purely for the light on the dash. Came ON below 7pse or close to that.

The 3rd, looks just like #2, but is reversed. NO oil pressure, NO contact, 7psi and above and the contacts close, thus earthing the fuel pump relay, and activating the fuel pump. Only on carby cars. Most are missing, as they were Lucas switches, leaked oil, failed to make contact, and that wire is now secured under a local earth point, more reliable.

 

Well, it is hard to say how the PO wired the thing at the swap. I did mine in what seemed logical and with the wires included in my John's Car conversion kit.


On my Sorta Chevvy, the GM units reposed at the rear of the valley between the heads.
Jag senders and wire colors retained. One is a simple on/off for the warning light. The other as I see you recognize is resistance sensitive. Don't cross connect as I did the first hook up.


But, once found, I'm with Doug. At first my OP's were just right, but later in it's life, it went "wonky". As the lifters were quiet, I knew I had OP, despite what the guage said.


I went shopping for a mechanical guage. No luck??? So, I got a guage kit. Sun Pro.
Sender and guage and wires. I plumbed it in in lieu of the Jaguar unit. Slick 40 #'s, as is normal for SBC's. And, for the fun, I hooked that sensor to the Jag guage. OK as well, 40 #'s!!!


But, I got a NOS Jaguar sensor from David Boger at everydayxj and all has been well since. Tossed the wonky unt so as not to confuse me or another at another time.
Look him up, a good guy and a great resource.


Carl

 

Thanks for input Carl, I too believe my oil pressure is OK. The engine runs and sounds nice and quite. The 2.5 inch pipes out to inline thrush units are another story. I may end up swapping back in mufflers at a later date as I think it's a little out of character for this fine lady to be so obnoxious.


But I'm a bit finicky about having working gauges, especially ones that read in the correct direction. When I asked the PO about the High pressure indication he stated; " High is better than low".

 

I'm with you. Right is better than wrong!!!


I like the sound of mine. As you say, fitting for a dignified lady. Classic ram horn manifolds. An after market new set that came with engine pack I bought from a recycler. I ground them along the inner top to get valve cover clearance. Why, I'm not sure. A built a connector at the right rear for the EGR to replicate the GM method.


A great pair of down pipes at a great price from Jim Johnson at Sun Coast in Punta Gorda, FLA. I drilled them and welded on bungs for the O2 sensors. Guessed a bit wrong as to the optimum location. Not quite but work just fine.


I kept the two Jaguar mufflers that are just before the IRS cage. As well as two small glass packs that a PO welded in as replacements for the Jaguar resonators.


A local muffler shop did a nice job of adding two cats and an H pipe to get from the down pipes to the Jaguar mufflers. Flanges and nuts and bolts will allow that "connecting assembly to be dropped if required.


It purrs nicely, definitely a V8 sound, but far from obnoxious. No drone or rasp or back wrap. I attribute that at least in part tot the "H" connector. If I were in for more performance an "X" connector might be a better choice. But, am I pleased, oh yeah....


Carl

 

All new, but a little mouthy.

 

My feelings regarding muffling Jaguar power plants, no matter what engine, is that they should be as near Silent as possible but breathe Very well, so the engine has Full Power in an Instant (off like a shot), but still be virtually Silent. Think "Sleeper."

Straight pipes are OK for some cars, but definitely undignified for an Xj6.
(';')

 

A very nice install, no question. Piped very well. But, where are any silencers/mufflers ?


I see the "H" pipe is in the system. That should even the pulses that leads to drone, back rap and rasp.


The 90 degree bend at the aft end suggest straight pipes with exits just in front of the rear wheels !!! Mouthy!!! I'll bet !!


Carl

 

Carl,


Here's the rest of the story or should I say the end of the story.

 

OK, you have the same resonators that came with the car but not the S-pipes (I rather like the S-pipes myself, they add to the Uniqueness of the Xj6).

Some people put glass packs in place of the resonators.
(';')

 

Greg:


I suspect that if you added a simple pair of "turbo's" just in front of the cage, it would be a lot less "mouthy" yet, "announce" the presence of a V8.


Elinor:


Exactly, my PO did install a pair of smallish glass packs in lieu of the original resonators. Even in 4.2 mode as it came to us, it sounded just fine. OK, except the "rascal" welded all the joinery !!!!


Carl