PFF - Pennock's Fiero Forum, PDA Edition

ECM upgrade (1227730) for stock 2.8 (Page 79/107)

Darth Fiero

OCT 10, 02:40 PM

quote

Originally posted by Madess:

It only comes on occasionally.

Like the whole ride to work today it was fine...

Correct me if I am wrong, but if it was a wiring issue, it would be on all the time?

So I am thinking the egr valve itself is a problem, or a vacuum leak is definitely a possibility, I need to clean things up in the engine compartment.

The EGR diagnostic does not run continuously. Sometimes it will only run when you are decellerating from a highway speed. So even if you had an electrical problem the light may not come on a stay on all the time.

-ryan

Madess

OCT 17, 11:16 AM

quote

Originally posted by Darth Fiero:

The EGR diagnostic does not run continuously. Sometimes it will only run when you are decellerating from a highway speed. So even if you had an electrical problem the light may not come on a stay on all the time.

-ryan

Ah, it does happen when decelarating or driving slow, so I will check the egr and vacuum leaks.

americasfuture2k

OCT 19, 07:45 PM

how many connections go to the power distribution block right under the C500? how many are on the 11mm nut one and how many are on the 10mm nut one? how many seperate grounds are there total on all of this after the conversion? any way to tell if the ecm is working? i think i may have fried mine, how? i have no idea, if its getting power and ground.

------------------
1987 Fiero GT built by my brother, merlot566jka, 3500 LX9 from 06 Malibu, WOT-TECH.com 1280 grind stage 3 cam, LS6 valve springs, 1227730 ECM conversion, Darrel Morse solid aluminum cradle mounts, Truleo headers modified to fit the 3500, 36# inectors, 70mm 4.3 throttle body adapted to 3500 intake, ported heads, upper and lower intakes, lightly polished, tcemotorsports.com crank trigger wheel, CenterForce dual friction clutch, Flowtech Afterburner muffler, 2.5" piping, cat deleted, EGR deleted, SinisterPerformance tuning, C6 Corvette exhaust tips. projected to be 35 MPG with a guesstimate of 250 hp at the motor

[This message has been edited by americasfuture2k (edited 10-19-2008).]

americasfuture2k

OCT 22, 07:28 PM

ok, so on the secondary harness connections, pin GF14, gry/red, is A/C pressure sensor signal, connect to A/C pressure sensor terminal C

what is terminal C? on what pressure sensor?

------------------
1987 Fiero GT built by my brother, merlot566jka, 3500 LX9 from 06 Malibu, WOT-TECH.com 1280 grind stage 3 cam, LS6 valve springs, 1227730 ECM conversion, Darrel Morse solid aluminum cradle mounts, Truleo headers modified to fit the 3500, 36# inectors, 70mm 4.3 throttle body adapted to 3500 intake, ported heads, upper and lower intakes, lightly polished, tcemotorsports.com crank trigger wheel, CenterForce dual friction clutch, Flowtech Afterburner muffler, 2.5" piping, cat deleted, EGR deleted, SinisterPerformance tuning, C6 Corvette exhaust tips. projected to be 35 MPG with a guesstimate of 250 hp at the motor

Primaris

OCT 23, 12:56 PM

TLDR

Why go with a GM ECU over say a MegaSquirt 2?

Darth Fiero

OCT 23, 01:53 PM

quote

Originally posted by americasfuture2k:

how many connections go to the power distribution block right under the C500? how many are on the 11mm nut one and how many are on the 10mm nut one? how many seperate grounds are there total on all of this after the conversion? any way to tell if the ecm is working? i think i may have fried mine, how? i have no idea, if its getting power and ground.

The smaller stud has the 2 fusable links connected to it that power up the entire car (except the ECM). The larger stud has the alternator charge wire, battery connection, and ECM power wire connected to it. Both studs are connected together by a shunt (that is actually part of the ring terminal for the charge/ECM wires).

Darth Fiero

OCT 23, 01:59 PM

quote

Originally posted by americasfuture2k:

ok, so on the secondary harness connections, pin GF14, gry/red, is A/C pressure sensor signal, connect to A/C pressure sensor terminal C

what is terminal C? on what pressure sensor?

Ok, for cars running a distributor and using the $88 F-body V6 mask, the only A/C related pressure monitoring device is a high side pressure switch that is normally closed (opens with high pressure) and connects to terminal BD12. You can simply ground the wire going to ECM terminal BD12 if you already have some other means of compressor protection wired up (stock Fiero A/C system should already have this).

For DIS cars, there is an A/C pressure sensor used. This sensor mounts on the high-side A/C line and reports actual pressure readings back to the ECM. The sensor has 3 terminals, A = Sensor Ground Input (BB5), B = Sensor Signal Output (GF14), C = 5v Reference Input (BA4). If you are using a programming code mask that requires a 3-wire A/C pressure sensor and you don't hook one up to the ECM, then the ECM will never be able to control the A/C clutch relay. This means the ECM won't know when your A/C is turning on (even if you feed it an A/C request signal) and this could cause stalling and idle problems.
(revised 8-14-2014 to correct some information)

-ryan

[This message has been edited by Darth Fiero (edited 08-14-2014).]

americasfuture2k

OCT 23, 05:47 PM

hmm, so to complicate things, wonder if that will be needed fo my ac compressor?

Darth Fiero

OCT 23, 06:14 PM

quote

Originally posted by americasfuture2k:

hmm, so to complicate things, wonder if that will be needed fo my ac compressor?

no, you won't need it as long as your fan still turns on when you select A/C on the HVAC control panel.

[This message has been edited by Darth Fiero (edited 10-23-2008).]

americasfuture2k

OCT 23, 08:52 PM

rock on, thanks for the info. clears that up.