MPS, ECU calibration theory, I need Jeff and Geoff, + more experts Options

[brant]

So after 2 days of searching and re-searching I have a theory.
follow with me here.

My ECU is apparently bad.

I have a good MPS but its an 049 (1.7)
I happen to have a good ECU spare that is the 037 (1.7) model

I know brad's website clearly says that the factory 73 2L set up used the 037ECU and 037MPS coupled with a ballast resistor (270 ohm)

Jeff and Geoff,
how close (or far) are the calibrations for the 049 versus 037 MPS units.

what I'm theorizing, is could I avoid buying a ECU and paying calibration for my MPS.... (this is a junkyard motor that might not even run and before I spend more money I'm trying to get away with the parts I already have)

Here is my thoughts:
If I "borrowed" the wide band 02 from the race car
could I possibly run the 037ECU and 049MPS, with the correct CHT and an adjustable reistat to compensate for my MPS?

I could use the wide band to perform test runs under load and then adjust the reistat or adjust the MPS to try and get the correct ratio's....

Is this stupid?
should I just buy an ECU and MPS instead?

and since my motor is a 75 with plugged air ports, should I buy a 74 combination or stick with the 75 combination? (I'm guessing the 75 combo is set leaner for emissions purposes and I don't have emissions)

ahhggghhhh..... I need brad anders to fix this beast.

tia
brant

[JeffBowlsby]

Its very unusual for an ECU to go bad. Do you have access to a known good ECU to swap in?

Not sure I can help but here are a few morsels:

The 037+049 MPS are not close at all calibration-wise.

Keep in mind that each system for each engine size and FI group of components uses a unique combination of pulse-width, injector flow rates and sensors, making interchangeability of components not optimum.

The TS2 ballast resistor, fixed or variable, is only effective during warm-up. Once warm-up temp is obtained the ECU takes over and the TS2 is not a factor in determining pulse-width.

[John]

Which ECU do you think you need? I can check my stash. I'm getting rid of all my D-Jet parts (or trying to). If I've got the one you are looking for, I may be able to send it to you for shipping cost....

[TROJANMAN]

brant,
also check craigslist, i think jim posted an ad for all of his parts.

[brant]

QUOTE (bowlsby @ Feb 13 2006, 11:10 PM)

1) Its very unusual for an ECU to go bad. Do you have access to a known good ECU to swap in? 2) Keep in mind that each system for each engine size and FI group of components uses a unique combination of pulse-width, injector flow rates and sensors, making interchangeability of components not optimum.

First let me thank you for taking the time to indulge my crazy ideas

1) I always heard the ECU's never failed. So when trying to get the motor to run on saturday I really didn't even suspect the ECU. I tested all of the components, spark, injectors, 23 wire harness to ECU for continuity, compression, and valve adjustment. It wouldn't even hit or fire at all.

finally out of desperation I plugged in my 037 1.7 ECU and cranked it over.
It not only hit, but started running on the very first crank.

I put back on my ECU that came with the motor (rusty, no surviving part number) and again would not even hit.

so I'm nearly positive that its the ECU and now I figure I can use the 037 or else buy one.

2) I know mixing and matching of components is NOT recommended. But since I happen to have an 037 ECU that works, I figured I could use the corresponding 1973 037MPS that fits my ECU for the 1973 2.0

(seems the 037 ECU is the only one that was used on both the 1.7 cars and also the 2.0 cars)

Would it be a bad idea to backdate a 1975 motor (with no injection ports and backdated exhaust) to the 1973 F.I. specs?

and finally, since I have access to this wideband I was being a cheap skate and thinking perhaps I could calibrate my ECU to an 037 spec by checking A/F ratio under load. I know I'm being a cheapskate, but I'm trying to get a junkyard motor to run with parts I have.

I guess otherwise, I could still use the 1973 2.0 specs (unless that is a bad idea) and just pay the calibration fee without the ECU purchase fee.

brant

[brant]

QUOTE (JOHNMAN @ Feb 13 2006, 11:15 PM)

Which ECU do you think you need? I can check my stash. I'm getting rid of all my D-Jet parts (or trying to). If I've got the one you are looking for, I may be able to send it to you for shipping cost....

John, thats a dang nice offer sir.
but I'm not even decided yet which specs I should shoot for:

1973: then I only need to pay calibration fees on the mps I have and don't need another ECU

1974: then I need ECU # 0 280 000 043/ or 044 (cu14x)

1975: then I need ECU # 0 280 000 052 (cu 16x)

I'm trying to figure out if I need to buy 1 or 2 components, and which one would be the best combo for the very minor modifications to this junkyard motor (plugged air ports)

brant

[JeffBowlsby]

QUOTE

Would it be a bad idea to backdate a 1975 motor (with no injection ports and backdated exhaust) to the 1973 F.I. specs?

Not at all, this is a good idea.

QUOTE

I could calibrate my ECU to an 037 spec by checking A/F ratio under load

Bass ackwards....You have a WB O2 meter, use it to calibrate the MPS. No fee needed...its DIY. (IMG:http://www.914world.com/bbs2/html/emoticons/cool.gif)