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-Injection/showthread.php?374-1228062-ECM-Information-4E&highlight=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
(http://www.gearhead-efi.com/Fuel-Injection/attachment.php?attachmentid=955&d=1323210744)

[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.

[blue68deville]

You will need the diag port to solve this, I'm betting you have codes set and will need some sort of bin adjustment.
Its all pretty easy, this is the right place to come.
Sounds like a cool project, it doesn't take much to get that little car moving fast.

[dave w]

I am trying to locate a diagnostic port to pull codes

Good Plan!

dave w

[Tom 79 Heather Won]

I am having difficulties in finding where to pick up a OBD1 diagnostic port. It appears that when the wiring harness was salvaged the port was left behind. Does the OBD1 diagnostic port have a plug connector to connect to the ECM? If so, I believe that I may still have the plug that connection. It is a 9 pin connector. Thanks in advance.

[dave w]

I am having difficulties in finding where to pick up a OBD1 diagnostic port. It appears that when the wiring harness was salvaged the port was left behind. Does the OBD1 diagnostic port have a plug connector to connect to the ECM? If so, I believe that I may still have the plug that connection. It is a 9 pin connector. Thanks in advance.

I think you need to do some wiring? See attached schematics.

dave w

[Tom 79 Heather Won]

Dave, Thanks for the schematics...please advise the type of wiring connection that represents the ALDL side of the schematic.

[dave w]

Dave, Thanks for the schematics...please advise the type of wiring connection that represents the ALDL side of the schematic.
Wire ECM pin A8 to ALDL connector pin E
Wire ECM pin A9 to ALDL connector pin B
Wire ECM pin A12 to ALDL connector pin A and splice with chassis ground

Wire service engine soon / check engine light to:
ECM pin A5
Ignition Switch On / Start with a 10 amp fuse

Connector pin information from the Dynamic EFI website: http://www.dynamicefi.com/RePinHowTo.php



dave w

[Tom 79 Heather Won]

Awesome Dave. That looks like an OBD 1 port. Could you do same with OBD 2 port? Would there be any advantage using the universal OBD 2 port?

[fastacton]

It's an OBD1 system, so an OBD2 scanner wouldn't be able to communicate with it even if you did wire in the port.

[Tom 79 Heather Won]

Fastaction...just wondering. Then why are there adapter plugs that go from OBD 1 to OBD 2? I do not own a diagnostic tool and until I get one, was just thinking of going to AutoZone to have the codes read. What makes more sense... buying a code reader or getting software for a PC? I am very new to fuel injection and ECU's. Tom

[Tom 79 Heather Won]

Would a OBD1 port off of a full size pickup with a 305 work for a 2.8 tbi?

[fastacton]

I would think that those adapters are specific to the scanner they're used with. OBD1 and 2 use completely different protocols. My Snap-On scanner will work with OBD1 or OBD2 as long as I have the proper adapter and cartridge plugged in, but my handheld OBD2 scanner just doesn't have the capability to talk to OBD1. Nowadays, the best way to go is to get a cable or device (like the Moates APU1) and software to use on your PC, there's no substitute for datalogging. Another bit of info, most OBD1 code readers require you to input portions of the VIN to determine what kind of ECM/engine it's connecting to.

How are you liking the power of the 2.8 so far? I'm trying to find a good engine to swap into my GT6+ and it's one of the few V-6s that will fit without major cutting.

[Tom 79 Heather Won]

Fastaction, thanks for the reply. I am very happy with the power and drivability of the B. Keep in mind that power is relative to weight and gearing. The car is around 2300 pounds. I have a T5 out of a Camaro and 3.9 rear. She will shit and go... have buried the 120mph Speedo on the highway once. The real joy to the car is the torque that the 2.8 brings over the inline 4. Makes the gearbox very versatile. Perfect,IMO, for the curvy road thing it is. Tom.

[fastacton]

Would a OBD1 port off of a full size pickup with a 305 work for a 2.8 tbi?

Yes, just get any port from an '87-'92 TBI car or truck and you should be good.

[fastacton]

Fastaction, thanks for the reply. I am very happy with the power and drivability of the B. Keep in mind that power is relative to weight and gearing. The car is around 2300 pounds. I have a T5 out of a Camaro and 3.9 rear. She will shit and go... have buried the 120mph Speedo on the highway once. The real joy to the car is the torque that the 2.8 brings over the inline 4. Makes the gearbox very versatile. Perfect,IMO, for the curvy road thing it is. Tom.

Thanks for the info. My GT6 is about the same weight or a little lighter, so it's starting to sound like that might be the way to go. I kinda want to keep my 4 speed with overdrive unit, so I'll have to figure that out.

[Tom 79 Heather Won]

Was lucky enough to get a OBD1 port today off of a full size Chevy. Had to move pin d to e on the OBD1 port. Used a couple of Heathers hair pins to remove the wire and connector. Hope to wire it tomorrow... then chasing codes ect.

[Tom 79 Heather Won]

I pulled down codes 12, 24 and 54. Code 54 seems like it may be something that makes some sense. Does that I need to replace the EGR solenoid? Assuming no vacuum leaks.

[fastacton]

24 is the VSS, I assume that you're not running one? It would probably help your drivability to wire one up, but I don't know that it's causing your problem. Do you know if you have a manual or auto transmission .bin in it? If it's an automatic .bin, you could try grounding the park/neutral wire (B10 at the ECM) and see if that has any effect.

54 looks like it's fuel pump low voltage. The fuel pump gets it's power from the battery hot connection, make sure you have good voltage there. I'm sure there's nothing wrong with the original Lucas wiring in your car, right?

Here's a good place for code reading info: http://www.gearhead-efi.com/Fuel-Injection/showthread.php?3-Checking-for-error-codes-and-troubleshooting!&highlight=troubleshooting