[Canyonero]

I'm having problems getting my Trooper w/ 3.4L SFI to run in closed loop. Took the truck over to Shucks once to get the code read (my current reader is only OBD2). The CEL is related to an O2 sensor. Swapped them and I still get the code. Shucks is 30 miles from here and it's not practical to run over there when I'm troubleshooting.

I'm planning on getting into tuning, I already bought a 1227727 but it isn't installed (going to make up a new harness). Currently I'm running a 16196742, and I want to get my engine working properly before I start tweaking with anything else.

With the ALDL interface to a PC provide me with everything a code scanner would, or should I still buy one of those? (such as this Equus 3120 Kit: http://www.amazon.com/Equus-3120-Dia...8325003&sr=8-1)

Are the moates products worth the expense? I'm eying the APU1.

[1988GTU]

Why not do the paper clip trick and then reference for the code on here to find possible faults? Unless you need live data to stream, I see no need for a semi modded-stock obd1 engine to utilize a scanner.

[The_Raven]

Originally Posted by 1988GTU

Why not do the paper clip trick and then reference for the code on here to find possible faults? Unless you need live data to stream, I see no need for a semi modded-stock obd1 engine to utilize a scanner.

He has an OBD1.5 3.4 SFI PCM from a '94 or '95 F-body.

Sometimes the best solution to get things tweaked is to swap to the new ECM.

Case in point, a friends truck that he and I added EFI to, ran poorly on the original ECM that I installed, I mean it started and idled (after some tweaking), and would drive just fine, but it didn't like to idle in gear, and stalled whenever the truck came to a stop.
I swapped to a different ECM (from a '7747 to a '7730), and it has never ran better. I have about 45 minutes to a hour of tuning into the new ECM and program, where as I had days into the old ECM.

What exactly is the O2 code? Possibly for the rear O2 sensor? If it is, this would be just another reason to swap to the other ECM.

Yes, moates products are worth it. I would suggest however to go the seperate route. (Ostrich, ALDU1+CABL1, BURN2) I suggest this only because I seem to read of people having issues moreso with the APU1, than the seperate route. Don't get me wrong, I love the idea of the APU1, and had considered getting one myself, and still am, but for in car tuning I will use my seperates.

[1988GTU]

I thought he was referring to the 90 3.4 in his sig. I had no clue that he had it swapped to the other system.

[The_Raven]

Originally Posted by 1988GTU

I thought he was referring to the 90 3.4 in his sig. I had no clue that he had it swapped to the other system.

That is the vehicle, which is a '90, the electronics are not.

[1988GTU]

Originally Posted by The_Raven

That is the vehicle, which is a '90, the electronics are not.

Thanks, this one had me going for a minute there before you replied in this thread.

[Canyonero]

Right, engine swap from a '94.

I didn't write the code down. Should have I suppose.

I don't have a rear O2 sensor, just the two banks. Trouble was with the right bank. Truck runs great, just gets terrible gas mileage. When I pulled the O2 sensors, the right one was black with carbon and the left one was clean. I bought AC Delco sensors, though they have the EXACT same markings as the Bosch. Came out of the same factory I'm sure.

[Canyonero]

Originally Posted by The_Raven

He has an OBD1.5 3.4 SFI PCM from a '94 or '95 F-body.

Sometimes the best solution to get things tweaked is to swap to the new ECM.

I think you're right. I don't actually have a 3.4L ECU, I have a 3100 ECU (16196742). I might as well push forward with the 1227727 swap as I'll never get the iron head to work right with that ECU.

[The_Raven]

A Live search of that ECU number indicates that it is indeed a 3.4L F-body ECU.

[Canyonero]

I get this when I google it:
http://www.autoecmecu.com/chevrolet-...6742_3062.html
http://www.enginecontrolunits.com/ca...A/1995_rnr.htm

I've never seen it listed as a 3.4L...