Hi all. I have kind of a lengthy question, but please bear with me... Here goes. My 63xke 3.8 with triple Su's is having a running problem after it warms up. It starts great cold, runs nice as I pull the choke off one detent at a time, but when it gets warmed up to where the choke is fully off, she starts caughing , backfiring through the carbs and then ends up puking out. When trying to restart it after she pukes out, it seems to be flooded out. The engine almost seems to lock up and not want to turn over, i have to let off the starter button then hit it again. The car doesn't get driven much and almost everything on it looks original. Here are my thoughts as to what it could be,: 1) the dizzy cap (inspecting it the center electrode doesn't protrude hardly at all, and doesn't seem to be spring loaded.. Is this the way they were meant to be?). 2) the coil putting out less voltage as it gets hot. 3) the vacume advance is not properly working(but would that make sense since it runs smooth and sounds great when you rev it while its warming up yet?). 4) a valve or valves sticking as the engine heats up. 5) a carb issue? Possibly running too lean after the choke is set to the run position? A lean condition can cause backfiring through the carb as to what I've read....
I personally am leaning towards the vacume advance... The way it doesn't even want to turn over and almost locks up for a second, it just really reminds me of a timing issue. Is there a thermo sensitive valve in the vacume advance line that allows more or less vacume to the dizzy as the engine heats up?.. Any help would be really appreciated. I don't have any manual or repair info so not really sure how these things are set up, but I like to theorize out the issue before throwing parts at it .... Specially when a set of original plug wires is $250.00. Lol.... Plus, it sharpens our skills as mechanics.

 

OK, so I had a chance to peek at my running problem, I found that the dizzy cap center electrode was not protruding far enough down, it is as I suspected,(the center electrode is spring loaded and should not be pushed up into the cap)... Seems it was stuck up in there and wasn't making contact with the rotor.

Took it for a ride and on the way home it seems to still be having trouble when pushing the accelerator pedal down more than just an inch or two.... Any more and she seems to be stumbling and not sounding well at all.

Took out the spark plugs and all of them are black covered. Running rich. I will replace the cap and rotor and plugs and give her another go....

If anyone has info on how to set timing, vacume advance, and carbs, I would love to hear from you... I have yet to track down any of this info. Thanks and hope to hear from someone.

 

So I have to assume that you know how to use a timing light. Set the timing at 10 degrees BTDC as per the book to start off. Adjusting the carbs can be trickey. Several steps there. If you don't have a book, GET ONE! Either the Complete E Type by Bentley, or some other basic E Type work manual.

You have to first set the carbs up to a begining point, set up the linkage, etc. Then you have to adjust the needles/jets, the airflow into each carb, then you can adjust the mixture. You'll need a Unisyn or something similar.

I know this isn't very detailed, but it is all laid out in a good manual. Good luck.

Charlie

 

Hey charlie, thanks for the info.... Do you have any idea where I can find a download for the manual?.. I've checked my public library and they had a "Motor" brand repair book, but it sure didn't give much info.... Not what I expected anyway..... I have yet to find anything on the vacume advance setting....

As for knowing how to use a timing light... Yes.. I do know how to use one of those..lol.. As for the carbs... I assume the way they are is a good starting point...I will use a hose and use the hiss test to make sure they are synced......upon Inspecting the linkage, it appears that they are all opening at the same time.... So until I get my ignition parts and a manual I am pretty much just waiting...

 

Check this out: The Complete Official Jaguar E Manual Robert Bentley Used | eBay

You NEED this manual.

Charlie

 

Hey, thanks charlie..... That is awesome!!! I'm going to buy it.....I can't wait to have it in my hands!!!

 

'Tis the bible...I've used mine for 40+ years, so that most of the pages are separating from the spine.

 

Mate

ASSUME NOTHING IS CORRECT !

Start at the beginning, work thru all of it.

The factory Manual is the best but Bentley is very good also. Coils are usually a problem. Setting the points and timing are first phase critical. If it is running at all, you can figure it out. Hard push on accelerator is usually where some moron has put a back door spring hold the carbs at idle when it's not the problem. It's the idle screw. Make sure each carb has it's butterfly is fully closed before they are linked together. Then make sure they all open together. Start with the basic set up in the manual. Have a small propane touch? You can use it to see if the throttle shafts are leaking. open the valve hold it near the shaft and it it's leaking you immediately hear a change in RPM. Check both sides of each carb. Now you need the proper rebuild kit. You'll be lucky if the red metallic tag for each carb is still under the fuel bowl banjo bolt. That will help with proper kit.

Check gaskets everywhere on intakes.

Do that and you'll have earned a good bit of respect from E-type owners !

Glad to help, ask any questions, the dumb question is the one you don't ask!

Robert

PS Haynes make a great SU Book "SU CARBS Owners Workshop Manual"

PPS What does S U stand for ?