Problems adapting Super-enhanced ECU to 5-speed manual 5.3L V12

Don’t know about that “wasn’t compatible” part , as said mine stalled between shifts after the 5sp installation.

When I sent my ECU over to AJ6 I sent a letter along stating every thing that wasn’t stock, no cats or air pump, electric fans, 180 stats (engine drag??) & 3.54 diff. Don’t know if any/all that made a difference in the ECU setup.

The other “real PITA” was stalling when @ operating temp (210F) during restarts. I rerouted the fuel line away from any heat. The only thing that cured the situation was doing away with the stock fuel regulator’s & installing a adjustable one. I increased the factory set fuel pressure of 35psi to 40psi. That worked!!

Larry

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Thanks! You wouldn’t happen to have a part number on the adjustable fuel regulator, would you?

Yes but, the car & info is in my Florida home & I’m Pgh, PA until around Nov 12. I’ll see if I can find anything while I’m in Pgh. When I get to FL I’ll get you pic’s & info

Dan:

My car is Marelli. This has no effect or connection with the ECU mod that is needed for a manual transmission, however.

-M

I found the Fuel pressure regulator (FPR) I have ,DeatschWerks DW. I don’t know the part # but I believe their all pretty basically all the same . What’s nice about most aftermarket FPR is a outlet to hook up a fuel pressure gauge, something Jaguar don’t have. Can’t remember where I bought it . I think Ebay .

Larry

Dan,
Retracing your problem are we on the same track ?

Appears to overfuel when accelerating.
Or at least you say it does not give “normal” response.

I know you have no problem with the original ECU.
That is a real puzzle.
All the same, hard to think Roger’s slight tweaking of the fuel map causes so much headache.

BTW, did you check the vacuum line to the ECU mentioned by Mike90 ?
If there is a restriction in that line you will not notice in normal cruise or slow throttle changes. But rapid changes while accelerating or starting will delay the information to the ECU and it will not be at the correct point on the fuel map.

Way back you said:
“Testing the throttle pot with the SE-ECU, it runs rich with a minimum idle of 2000rpm, and when I hit the throttle, it still sputters and sounds like fuel is flooding the piston chambers. Heavy sulfur odor from the catalytic converters working overtime.”

You need to be careful when claiming the mixture is too rich.
A weak mixture will not always ignite in the cylinders, but can pop in the hot exhaust.
My experience is not so great I can always tell that failure to fire in the cylinders is due to either too rich or too weak a mixture, especially if it just a momentary thing.

No matter what, you can only get a 2000RPM idle is if you have a lot more air then normal getting into the engine. The throttle pot, ECU, FPR, O2 sensors do not directly account for 2000RPM idle.

A quick answer to the apparent fuelling problem is take the car to a dyno equipped shop. They are common in large towns, and a good operator can quickly zero in on the problem engine performance point and see what gives.
My guess is it will cost about US$100 - US$200 for 30 to 60 minutes on a dyno.
Take both ECUs, then you can try both on the dyno to see the difference.

It is true that with the ECUs you have the only way to make change to the base fuelling map is to change the FPR setting. I doubt that is the answer.

Not to hijack, but I’m curious about this aftermarket ECU solution. I have a 1975 D-Jetronic V12 that barely runs. I’m getting tired of dealing with 40 year old electrics and would be interested in a modern setup.

Alabbasi, I’d like to know more about your problems, but it would be best to start another thread.

AL ,i use the SDS (simple digital systems) Canada!
been since 1994, on V12 Jag pre-he. for fueling, for ignition i use the old Crane XR700, its adequete barely!

altho SDSSDS%20programmer%20pix%20004 been updated 3 times,technology waits for no-one, updates were low costs!

i like ,but i am used to it, programming can be tedious, but very educational.center%20consol%20J%20-bond%20system%20002

lately MS (Megesquirt systems are very popular), and much help and more advanced technologies!
plus online forums.

there are many others , but cost can skyrocket, altho E Bay has a lot of used /new , to pick and choose!

ron

Ron, thank you for your response. I’ll read up about them.