So THE JAGUAR AJ6 ENGINE - 3.2, 3.6, AND 4.0 LITRE / AJ6 Engineering says the air mass flowmeter needs to be bigger to get more air into the engine. They also say that after boring out the unit, its circuitry has to be recalibrated.

Have you tried this modification on your Jag? Do you know where I could get the flowmeter recalibrated? Or do you know of a bigger flowmeter from another car (Mustang???) that might communicate with the ECU and not need recalibration?

Apparently doing this mod in addition to a Growler-type air filter can yield 20 bhp and is a good first step to waking up an engine.

 

That along with the plus torque intake manifold makes a big difference.

 

I would think any change in the MAF on a car of this vintage will require a tune to keep AFR's correct. And in my opinion I would look at MAFless in-other words add a MAP sensor and ditch the MAF.

 

That sounds sensible. I'm just learning about this stuff. At British Car Day in Ancaster, Ontario today I spoke with a chap who built/owns a SIII E-Type with a newer 6.0L V12 (and 5-speed). There was no MAF on it, just an air temperature sensor in the airflow after the air filter. So then I looked at an XJS with stock 6.0L V12 and it was the same. I wonder why it's different from my 6-cyl car.

Thanks for the suggestion, Warren. I'll do some research.

 

Both my 5.3 and 6.0 V12 are MAFless, and the guys here in Australia remove the MAF from the LSX engines and use a MAP.

 

Bear with me...I take it that mod requires the addition of a pressure sensor to the intake manifold? And the use of a different ecu?

 

Yes, the MAP (Manifold Absolute Pressure) sensor is placed after the throttle body, the LSX guys retune the GM ECU.

This is an interesting read

Problems with AJ6 "sort of Engineering" TOILET TUNE

 

Ya that's a good read. Good thing I don't have more money to move as fast as I would like on some of my crazy ideas. More reading to do.

 

So the V-12 has no air flow sensor? Dammit... I was hoping that was my issue. Guess I need to start taking more things apart now....

 

What is your problem?

 

After having the transmission rebuilt (4L80-E), the transmission shop hooked it up to their computer to test it out, it ran through all the gears successfully including reverse. Plug it into the car, and it remains in LIMP mode like it did before the trans got rebuilt.

Took it to a European only garage, they had it for a month and a half to try finding why the trans won't shift. One guy there who's a specialist on Audi's told me that he had the same thing with an A6 once, and all it was, was the MAF.....