Thread: programable memcal ?

the old GEMS (upto 1999) ecu can have the CO% base setting changed and then disconnect the O2 sensors so it cannot relearn a new setting (same as 1995 spec). the ign timing can be changed by fiddling with the wiring.
i do not think there are any tricks on the Thor (1999 on) ecu, although it never reads the throttle position at 100%.
the restriction with both is the inlet manifold.
normally the 5.0 go ok with the standard set up. are the cats and air flow meter all good?

What wiring changes will adjust the timing? May be beneficial for LPG installations?

cam angle (not crank) sensor failure default timing setting is different (i think it is 15deg) and i have been told that swapping the wire positions can give more advance, but i have never tried either so be careful.

Originally Posted by Rupert Prior

cam angle (not crank) sensor failure default timing setting is different (i think it is 15deg) and i have been told that swapping the wire positions can give more advance, but i have never tried either so be careful.

i defiantly dont need any more advance as it runs between 30-45 degrees according to the hawkeye. cheers anyway

Originally Posted by Rupert Prior

the old GEMS (upto 1999) ecu can have the CO% base setting changed and then disconnect the O2 sensors so it cannot relearn a new setting (same as 1995 spec). the ign timing can be changed by fiddling with the wiring.
i do not think there are any tricks on the Thor (1999 on) ecu, although it never reads the throttle position at 100%.
the restriction with both is the inlet manifold.
normally the 5.0 go ok with the standard set up. are the cats and air flow meter all good?

afm is fine and to spec and there is no cats. my problem lies in the cold start enrichment and base idle as it idles at 1800rpm until it warms up and then hunts like a **** warm, warm idle jumps between 450-900rpm, also im running 40 psi constant fuel pressure with 20% larger injectors and still have the ecu adding up to 15% fuel ontop of the std map. i can see what the settings are withe the hawkeye hooked up but unfortunately cant change anything. i think im just going to have to piggyback and autronic into it. and no there isnt any air leaks either.

Is it a GEMS or Thor?

Why did you increase both fuel pressure and injectors size?

Regards Philip A

OK, I was thinking about it, and have decided you have a GEMS , as The GEMS works on 2.5ATM and the Thor is already 3ATM and you cannot get easily to the fuel pressure regulator.

If you started with a GEMS, did you try to run it with standard injectors and pressure as there is usually a 15% ceiling that the ECU can handle.

Have you contacted Mark Adams who is considered THE authority on 14CUX and also GEMS? He usually can program a chip to accommodate larger capacity with near stock driveability AFAIK.

Do you have a standard cam in the new engine or have you installed an aftermaket cam? the symptoms you have described are often the result insufficient vacuum caused by a cam with incorrect phasing of inlet and exhaust timing, although who knows with the higher pressure and volume of the injectors.

Regards Philip A

Originally Posted by PhilipA

OK, I was thinking about it, and have decided you have a GEMS , as The GEMS works on 2.5ATM and the Thor is already 3ATM and you cannot get easily to the fuel pressure regulator.

If you started with a GEMS, did you try to run it with standard injectors and pressure as there is usually a 15% ceiling that the ECU can handle.

Have you contacted Mark Adams who is considered THE authority on 14CUX and also GEMS? He usually can program a chip to accommodate larger capacity with near stock driveability AFAIK.

Do you have a standard cam in the new engine or have you installed an aftermaket cam? the symptoms you have described are often the result insufficient vacuum caused by a cam with incorrect phasing of inlet and exhaust timing, although who knows with the higher pressure and volume of the injectors.

Regards Philip A

sorry its a gems, and originally 4.0L. the injectors were fitted when i first bought it they are bosch late model, they increased my torque and fuel economy on the std engine. the fuel pressure reg is no longer connected to a vacuum source as when it was hooked up it leaned out too much, ecu showed constant +25% in fuel trim. as for the cam its 204 @.050 both intake and exhaust with 450 thou lift.