Thread: programable memcal ?

Originally Posted by PhilipA

What is the LSA, as you need a narrow LSA to give vacuum for a MAF to read correctly.Standard 4.0 litre LSA is 109degrees.

Rover,ERR3720, IO28,IC77,EO66,EC39,DUR285/285,LSA109,OL67, lift0.390, 5.5,,Production ,4.0-litre, 109degrees LSA is theoretically correct for a RV8.

How many Lbs per hour are the injectors? Standard 4.0 are 23.5 and Bosch yellow Gen11 or 111 are 19Lb. So how big did you fit?? as 19Lb per hour is plenty for a 4.6 and should be OK with 5 litre if the duty % in the chip is increased. Holden 5 litre uses 19lb.
I guess my assessment without knowing much of the story is that your injectors are too big and the cam has too large an LSA.
Regards Philip A

LSA is 112 and dont remember the Lb/hr for the injectors but when we run them on the injector bench when we first put them in they came up roughly 20% in cc larger to the original BUT they ran in the std 4.0 and returned better economy and power, the computer used to run at -7% fuel trim on the old 4.0. apparently the set up in the 5.0 we used has been used before replacing the 4.6 with no problems, im wondering if there is much difference in the 4.0-4.6 maps. it drives like a dream when its over idle, it even chirped the tyres (32" maxxis 764's) on take off a few days ago.

first off unplug the stepper motor cold and it idles at 1250 instead of 1850

That is part of what the stepper does, at high resistance values on the ECU temp sensor it will add steps.

fuel trim with stepper motor unplugged -1-2% and plugged in -4-5% also no vacuum to fuel pressure reg

It seems to me that the ECU is not adding fuel as the revs rise with stepper.

I don't think the stepper has much to do with your problem, I think it is more probably inconsistent air volume through the MAF. See what it does with MAF disconnected, as it will be in "limp home" which is usually rich.

I take it this is a non cat car.

Regards Philip A