Ideas for 4 cylinder MPFI = Toyota 22RE with GM ECM?

[delcowizzid]

is it a 4 cylinder TBI memcal or port injection memcal.will run bad if its tbi memcal

[EagleMark]

Four cylinder PFI memcal.

[RobertISaar]

i'm betting 8D has another cylinder count value somewhere if it keeps triggering DTC41.

[EagleMark]

I think I've got all the chnges done for the BFUZ $A1 .bin Robert can you take a look and see if I did them right?

Didin't know if changes were needed in Dwell? Seems to show 4,6,8,cyl all at same hex with different values. I've changed nothing there.

[RobertISaar]

KRPMUP might benefit from being dropped a little, it is set for 900 using the original values from the V6(where it is 600). with the idle you're commanding, it might not be an issue though.

rev limiter likely won't be an issue for you for at the moment, set for 9300RPM.

KNUMCYL looks good.

Reference Pulses per Revolution might benefit from dropping down to 2, otherwise during "1 injection per reference while cranking" mode will deliver less fuel than expected.

KK41MODE should be $18 or $10, depending on how the limp-home cylinder select is setup on the MEMCAL(which i guess varies among the Q4 MEMCALs, you would need to either try both ways to figure out which won't throw a code or take a meter and check the pins manually). otherwise you'll set DTC41.

if you have alpha-n idle/coastdown fuel enabled(and current settings look to allow it), KINJXBC5 should be changed to match the injector flowrate you're using.



otherwise, it looks like you have everything that needs to be changed done.

[RobertISaar]

oh, and dwell should be fine as-is. the only thing reference period related there are the RPM thresholds that cause different amounts of base dwell.

[EagleMark]

Well it seems the reason I'm setting a DTC 41 is the four cylinder Memcal from the 8708 Quad Four ECM, the Netres is set for TBI as per this picture:
http://www.gearhead-efi.com/Fuel-Inj...ll=1#post36957

So any ideas how to change either it or a V6 memcal to I4?

[EagleMark]

KK41MODE should be $18 or $10, depending on how the limp-home cylinder select is setup on the MEMCAL(which i guess varies among the Q4 MEMCALs, you would need to either try both ways to figure out which won't throw a code or take a meter and check the pins manually). otherwise you'll set DTC41.

I thought the $10 was a mistake and supposed to be $80 ?

Since this four cylinder memcal is from PFI but netres set as TBI, could I just run $18 ?

[RobertISaar]

i think the 10 vs 80 mistake was another byte.... KNUMCYL, maybe?

i would run $18 and see what it gets you, AFAIK, the cylinder select resistors on the MEMCAL and the value in the code are not in effect at all when running normally, only when in LHM. DTC41 is simply to try and detect if the wrong NETRES/limp-home chips are being used for the calibration(like if someone were to program a V8 BIN into a V6 MEMCAL) or a total MEMCAL failure/not present.

[EagleMark]

if it takes the long memcal with 2 netres and a 28pin chip like ours this is cylinder select netres internals

Has anyone figured out how to make a 4 cylinder netres? Looking through the list there does not seem to be a USA 4 cyl memcal? Except maybe a turbo which I doubt I'd find.

So far running $A1 or $8D with a TBI memcal (which came out of a Quad Four MPFI) is failure!

[jim_in_dorris]

Mark, if the resistor isn't under the chip, trace the circuit for the tbi netres and find the resistor. clip it off, then just solder 2 resistors on top of the chip in the 4 cyl configuration.

[dave w]

Has anyone figured out how to make a 4 cylinder netres? Looking through the list there does not seem to be a USA 4 cyl memcal? Except maybe a turbo which I doubt I'd find.

So far running $A1 or $8D with a TBI memcal (which came out of a Quad Four MPFI) is failure!

I think using resistors on a Moates.net G1 adapter would be an option. I would jumper the correct pins with resistors on the G1 adapter, without a memcal. I would put a chip on the G1 adapter. I would then install the resistor modified G1 adapter / chip assembley into the ECM.

If that works, I would so some Series / Parallel resistors on the memcal to match the resistances in the picture.

dave w

[jim_in_dorris]

I like that idea Dave. I didn't even think of that.

[1project2many]

There are four cylinder netres in the US. Turbo Sunbirds, 2.2 powered Cavaliers, some PFI 2.5's, and some of the 2.3's are four cylinder PFI mode.

Differences in EFI firing mode:

MEM/CAL Mode Selection

Application Mode	Input Voltage(R29/R30 ratio)	Frequency Of Injection
1. Alternating TBI	2/3 VRFD + 10%	ALT. Every REF pulse
2. Single Injector TBI	VRFD + 0% - 10%	Every REF pulse
3. 4 Cyl. PFI	2/3 VRFD +/- 10%	Every 2nd REF pulse
4. 6 Cyl. PFI	1/3 VRFD + 10%	Every 3rd REF pulse
5. 8 Cyl. PFI	GND -0% + 10% (5v)	Every 4th REF pulse

The info above is a compilation of multiple sources and includes some corrections. Also cross posted here:
http://www.gearhead-efi.com/Fuel-Inj...ull=1#post3374

Also want to include information posted by Robert:

setting this to match your MEMCAL should remove the DTC41 from being set. i have the item listed as "Fuel Delivery Mode (KK41MODE)"
$18=TBI
$10=4 CYL PFI
$08=6 CYL PFI
$00=8 CYL PFI

Note that this is a completely different value than the "KNUMCYL or number of cylinders constant used for RPM conversions.


My GM EFI training manual dated 1998 states the 2.3l Quad engine fires injectors in "alternating double fire" sequence in which one pair of injectors is triggered every 180 crankshaft degrees, so each pair is triggered twice per combustion event. If you're trying to use the memcal in TBI mode you'd want to double the injector flow rate to provide the same fuel. If the injectors are large enough you might find the minimum calculated PW is less than what the injectors can provide.
Alternatively, you could cut the sense leg of the memcal and use two resistors to provide the correct voltage for 4 cyl pfi mode.

Also, I know that $58 provides a mode whereby the injectors are pulsed 1/2 as often for 2x the required time. This allows large injectors to provide reasonable fuel metering at lower load and rpm. Maybe there's a similar mode in one of the masks you're using.

[delcowizzid]

cylinder select netres is the chip furtherest from the eprom.just cut the legs for the required positions and solder resistors in place