i would also like to just say this.

every morning when i go out and start the Jag, it runs differently than the day before. i had it running pretty spectacularly last night. very responsive, minimum amount of backfiring, no bog.

this morning its loping like the wolrds biggest cam and is idling at about 250 - 300 rpm. nothing i do will lean it out enough to run better. playing with the ECU, playing with the TPS etc.

im not sure if its a temperature thing or just a tempermental thing.

its certainly not the CTS, cause last night i had it bridged and running great, and today it wouldnt even start bridged. i had to plug the CTS back in to get it to start.


EDIT: ive just had to unplug 2 vacuum lines so that the engine can get enough air to idle properly.

 

results of o2 sensor test are:

bank A: 0.95-1.0v
bank B: 0.77-0.8v

this was after a 5 minute warm up in warm weather.
so i guess that means the o2 sensors are good. seems clear that bank A is running much more rich. keep in mind that my AAV has been removed so bank B should no longer be drawing more air at idle than bank A.

 

Those look like virtually fixed readings to me. The sensors were probably not hot enough and/or are fouled


Cheers
DD

 

well i let it warm up for 30 minutes and i put a vacuum on the ECU to lean out the mixture enough to allow it to run.

0.7v across the board.

this engine runs ok in open loop. once it enters closed loop you have to trick the ECU for it to even idle.

 

If you have the AAV blocked off, how are you getting additional air at cold start, and how are you setting you warm idle? That would explain your lope at 250-300 on a cold start. Do you see a rise in RPMs as the engine warms?

Also, with the AAV installed, the two banks have negligible difference in A/F ratio at idle due to the balance tube. Even though it doesn't look like it you shouldn't really be seeing a difference.

Wow...is there anything on this car the PO didn't mess with?

 

Something wrong. The O2 voltages should be swinging back-forth constantly. I don't think has anything to due massive over-fueling but, still, at some point it probably should be looked at


Cheers
DD

 

well theyre supposed to be new.

 

definitely an open/closed loop issue. open loop runs ok. but pretty rich. closed loop wont idle at all. FAR too rich.

 

ive tried on 3 seperate occasions to do some research on the Megasquirt ECU kits for HE V12's and find MOUNTAINS of forums, tech talk, etc.

but where in the HELL do you buy the ECU, and which one of the 500 different ECU's/programs/kits do you need?

 

It's very confusing and not nearly enough info. I contacted 3 different dealers, gave them the same info and came back with 3 different answers and prices.

 

i think it deserves a thread.

 

M90, checking back in, maybe I missed an update. I'm current through your megasquirt thread. How have you been making out? Any progress?

 

well i got frustrated and decided to rewire the whole EFI harness and most of the amp wiring. then midway through that i decided to clean the V like someone suggested. so i took the intakes off, got fresh hose for the crossover, and new cam cover gaskets. now im just painting stuff up, polishing some of the steel and aluminum components, doing some upgrades, finishing up the wiring, and ill be sending the water manifolds off to the machine shop for the upgrade in the next few days. trying to source water rail gaskets and seals locally = failing.

giving the V12 one last chance to prove that its not worth lumping for a supercharged 3800.

and then somewhere in between the utter despair and overwhelming frustration of this build, i managed to find a soothing hobby.

 

...and that hobby is??

 

rebuilding the jag.


EDIT: BTW, thanks for recommending del city. after i boiught my wire they sent me a catalog. no kidding its an inch thick. lol
they have SOOOOO much stuff. i could blow my entire tax return on that site. lol

 

They send me emails frequently on sale items too. They have a lot of good, quality stuff!

 

Keep on it. You'll get there. Good luck. And don't lump it, the only thing worth saving on these cars is the engine. Might as well just go buy a GM car.

 

I have to disagree Darel, the body style on these cars has really captured my attention. There is just something about it that I like.

 

i would have to disagree as well. especially when youve got a rust free example such as mine. IMHO the worst shortfall of the XJS is the gearbox, and the second worst is the engine.

 

I think there is book of XJS shortfalls out there, about 1000+ pages Let's concentrate on XJS advantages, it is easier and quicker, cos there only one, LOOKS