4.3 ECM in a 2.8 TBI and motor?

[Tom 79 Heather Won]

Will a 4.3 ECM work with a 2.8 motor and TBI? This is in a non-stock application.

[dave w]

Will a 4.3 ECM work with a 2.8 motor and TBI? This is in a non-stock application.

I think yes, but I would need a little more information so I can be more accurate.

ECM part numbers would greatly increase the accuracy of my answer.

The 1227747 TBI ECM can run a 2.8 liter with a custom PROM chip.

dave w

[Tom 79 Heather Won]

1228062 is the service number

[dave w]

1228062 is the service number

This should help?

http://www.gearhead-efi.com/Fuel-Inj...hlight=1228062

dave w

[Tom 79 Heather Won]

Should I check the PROM chip? Not sure if ecm came from truck. This motor and computer is in our 79 MGB.

[dave w]

Should I check the PROM chip? Not sure if ecm came from truck. This motor and computer is in our 79 MGB.

Yes.

[Tom 79 Heather Won]

It appears to be AZNO OR AZNV 435. It was difficult to read. Thank you for your help.

[dave w]

It appears to be AZNO OR AZNV 435. It was difficult to read. Thank you for your help.

AZNU 91 S-truck 2.8TBI HO 5 speed with 3.42 or 3.73.BIN

dave w

[Tom 79 Heather Won]

Thanks Dave. What does 3.42 or 3.73 BIN refer to? Does this have to do with the rear end gearing? If so, mine is a 3.9. Also, my speedometer is broken due to the gear in the tail housing slipping on the main shaft. Would this be a problem for the computer?

[dave w]

What does 3.42 or 3.73 BIN refer to? Does this have to do with the rear end gearing?

Yes, gear ratios.

mine is a 3.9. Also, my speedometer is broken due to the gear in the tail housing slipping on the main shaft. Would this be a problem for the computer?

The ECM is looking a Vehicle Speed Sensor (VSS) Input. The VSS input can be disabled by placing the "Vehicle is in Park" wiring to chassis ground or setting the .bin file to manual transmission. Using a VSS is nice (greatly improves drive-ability), but is not absolutely necessary. Without VSS stalling in stop and go traffic is more likely.

dave w

[Tom 79 Heather Won]

Drivability has been pretty good... that being said, I do have a problem with loosing rpm's slowly over longer trips. It seems to reset itself by simply turning off and restarting the vehicle. Could be a fuel pressure regulation issue or ecm. I need to obtain a diagnostic port so I can search codes. I needed to be sure that the ecm fit this motor and tbi. It seems that it may be a fit. Your thoughts are appreciated. Thanks again for the assist. Been awhile getting this back on the road.

[dave w]

Data logging is better than a diagnostic scan tool. It can be challenging to get setup to data log, but well worth the expense and effort.

dave w

[Tom 79 Heather Won]

Dave, I need the port that the diagnostic tool attaches to. Would data logging attach to the same port that the diagnostic tool would? I have the wiring harness and ecm. I did not obtain the port and am beginning to look for on now that I know the year of the truck it came from. Thank you for helping me narrow it down. Also, I moved the fuel pump to a location adjacent to the tank. Hopefully, this will eliminate any fuel starvation problems I may have been having from my in-line fuel pump. This is the only fuel pump on the vehicle. I hope to road test it tomorrow.

[dave w]

Would data logging attach to the same port that the diagnostic tool would?

Yes,

dave w

[Tom 79 Heather Won]

Dave, road tested the car today and the same issue came up... car warms up and idle drops to 1000rpm's. Plenty of throttle and power. After driving as slower rpm's (neighborhood) the vehicle doesn't have power above 2500 rpm's. A quick turn off and restart of the car corrects it. I have noticed some minor variances with the idle, but no surge or stalling. The idle control valve has been replaced along with the egr valve. I am trying to locate a diagnostic port to pull codes, but in the meantime need to solve. Thanks, Tom.