hey all, I really need a pinout diagram/schematic of the 302 ECM. Can anyone point me to one? Google searches, and searches here have come up with nothing... Thanks

ttt - anyone?

Come on... someone has to have the schematics... I found some under '730 for an '87-'89 2.8 'W' code.... was the 'W' a 730, or a 302?

the 730 is speed density (MAP) ECM.

IIRC the 302 is MAF.

sorry doward i looke for the last few days while ive been packing the house and i havent seem them. if you goto the library look up this car


1986 chevy celebrity vin W 2.8 mpfi v6. or look up a 1986-1989 chevy camaros with a 2.8 mpfi v6. all those systems use the same 12277302 ecm. its a p3 with a 2732 eprom. are you swapping to a 1227730 ? just wondering.

If the '86 vin W is the 302, then that should be the same data I found here. Wait a second - that's '87-'89 Vin W. So you are saying the '86 'W' is a 302, but the '87-'89 'W' is the SD based 730 ecu?

Yes, I'm trying to convert to 730 from 302 (Maf to MAP) so that I can later change the a 749 ecu for forced induction...

The 730 has three plugs on the ECM

one 24 pin black, one 32 pin black, one 32 pin yellow.

1227302 is a C3.
1227730 is a P4.

The 302 has 2 connectors one 16 and one 24.
Like Saturn said the 730 uses one 16 and 2 24 connectors.

Wire it up and start with the 749 if that's your goal, no sense in spending all that time doing the cal twice, there is a signifigant difference 749 to 730 tuning wise.

I was thinking of that... but since the 730-749 swap is well documented, I figured I'd crawl before I walked... I'm seriously considering going straight 749 tho...

id say go ahead and grab the 749 from the start. messing with the 730 swap would just be a silly middle man step. there no sense in tunning with the 730 just to have to make the leap to the 749. btw what are you attempting to do here ?? the 12277302 $3a code has enough resoloution for a turbo or forced induction. itl read to about 230grs/sec and even the wildest 3.1's ive played with are 140grs/sec max so that alot of unsed fuel and spark tables. plus you could use the base cal to get started then just add the lowered timing and extra fuel up and above what your using now.

wtf? Are you saying that I can run FI up to almost 1 bar, running the MAF?

As long as the flow rate doesn't exceed what the ECM can recognize, then yes. And it sounds like he is saying the ECM is able to see airflow far in excess of what the engine will ever see.

Sweet! Once I get the turbos in, I'll run it standard, and then like 2lbs boost to see if indeed the maf recognizes it... if so... man, that'll be nice!

heres what im saying due to my expereicnes with a 1227302 runing $3a code.

a 2.8 even modified with a cam etc will max out around 134grs/sec. ive seen one pull 145grs/sec but thats rare.

the code can see upto 210grs/sec which is alot of boost most likely roughly 12psi. thats a good bit of boost.

if you port the maf you can cheat it a bit and run 250grs/sec and it wont know the differcne. removing the screens will let it flow 230grms/sec with the same linearity it has stock. just itll read a bit lower.

now the timing table goes to 210 grams sec so youll be fine there the thing is getting the

LV8 vs INJECTOR PW table striaght. youll also want to adjust the constant for high way spark mode etc. its not hard at all.

infact the factory timing table should work toe roughly 210 gram.sec of flow becuase i think the max timing up there is like 12btdc.

now the fuel it easy. there is no injector constant just the lv8 vs pw table. its easy to adjust.

WOT is basically like any other GM ecm. although i hgily recomend playing the AE pulse stuf lots of response hiding in there. and the PE mode is very conservative as well.

if you have and questions about $3a email me.

also tunercat has a Nice TDF for $3a the code in you recm.