ECM 1227748 Full Retard

[evilcowboy420]

Ok so here is what I did.

I am new so please forgive me if I have no clue what you may be talking about but I am more than willing to learn.

Anyhow back to what I did. So I was rebuilding a J-Body Sunbird 1988 2.0 TBI OHC Brazilian Engine. I was intending for a car that was as reliable as the day it rolled out the door with the popular GM messup fixed that caused a blown head gasket on cylinder 3 and 4.

So I did all that and was happy since the engine only had 73,000 on it. So I am the type of person once I do half a job I must finish it. This included cleaning the TBI unit on the car since it seemed to have several bad gaskets.

I followed all instructions and so forth and I can almost hear someone saying "why did you remove it noooooooooooo" I didn't find out till later after rebuilding the GM TBI the ECM goes full retard.

It is like the ECM cannot learn new settings after sitting a while and has to relearn everything.

The ECM in question is a 1227748 one I have read is an odd ball ECM since it uses a different baud to transfer data. Now I thought maybe something fried the ECM or it was just bad. So I replaced it and before anyone asks yes I changed the chip with the one that came from my car.

The car will not start without gassing in the morning, It stumbles and stutters until it is warmed up and does a surging idle.

I had read that I would need to get the ECM reflashed but this made no sense to me as the ECM in question has the ability to learn settings.

I figured I would ask you guys as it seems you guys probably know more about GM ecm's than GM themselves :P

Things that was done to the car so we don't beat a dead horse.

New CTS
TBI rebuild
New head gasket (resurfaced head)
New Ignition Coil
New Plugs and wires
New EGR
New Manifold gasket (exhaust and intake)
New Timing belt (cranked aligned to oil pan mark and cam aligne TDC mark)
Ignition timing adjusted to reflect 8 btdc as per the sticker
New IAC vlave
New TPS
New Fuel Injector
New Fuel Filter
New FPR Diaphragm (as per the TBI rebuild)
New ECM (same old chip)
New Map Sensor
New Breather Filter
New Air Filter
New PCV


As you can see I have almost exhausted the most common things that could point to the problem and I refuse to let this be a mystery that goes unsolved. My gut feeling is telling me fuel pump but I just don't wanna throw parts at it. I gotta get a hold of a fuel pressure tester to know for sure so I will be doing that next.

But the weird thing is before the TBI rebuild the car started without gassing. I am wondering if rebuilding the TBI could have compounded a weak fuel pump problem?


Anyway I know this is not a repair forum and I am fully intending to learn to use this software but I am at a loss and just figured there may be some things simple with the ECM that may make it finicky and cause this.

Any help is very much appreciated

[delcowizzid]

do you have any way to datalog the ecu?

does it run this shape TPS on the TBI unit

there are 2 different versions of this tps one turns backwards compared to the other and can make the ecu go into clear flood mode when cranking

[evilcowboy420]

do you have any way to datalog the ecu?

does it run this shape TPS on the TBI unit

there are 2 different versions of this tps one turns backwards compared to the other and can make the ecu go into clear flood mode when cranking

It looks close to the same but my book says it is non adjustable type. Could this be causing an issue because its gotta be moved slightly?

But yes it seems the ecm is going into clear flood mode when cranking.

[EagleMark]

Measure the voltage at TPS. It should be around 0.54 If it's way higherr like 4.5v then it is backwards.

[evilcowboy420]

Measure the voltage at TPS. It should be around 0.54 If it's way higherr like 4.5v then it is backwards.

Cool I will do that. I didn't know what the voltage was suppose to be so that is helpful. If it is somewhere like 1.5 would that mean it is off a bit or something? Just curious.

I Will post my results when I do it.