Hello,

I have a question about V6 Control Module vs timing.
After I put in a 3.4 V6 I have install a new V6 Control Module, this was broken (DOA) and we put in a old one.
Then we set the timing right and the engine works fine.
But I want to have all parts new, so I orderd (2 times) a new V6 Control Module (DELPHI DS10059)
When we changed the new module, the engine didn't run fine?
A lot of backfire, or even don't start.

The old module gives ECM code 42

We don't get it right with de new module,

You don't have to chance timing if you chage the module? Wright????

What I meen "If the timing is wright I can change the module, whitout any problem"???

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Fiero GT 1988 2.8V6
Fiero GT 1987 3.4V6 T-top
Buick roadmaster 1956 5.3V8


my_fiero@hotmail.com

[This message has been edited by my-fiero (edited 11-17-2017).]

True, Timing and the ICM have nothing to do with each other, but the code 42 is telling you that signals between the ECM and the ICM are not right. Look for wiring damage and perhaps a bad pin in a connector. Too many ICMs are bad when new.

You are correct. Changing the module only involves removing the distributor cap to access the module. The distributor positon doesn't need to be changed. If you bought the module locally, take it back and have them run a load test on it. The test should be initiated at least 3 successive times. Three times is usually sufficient to heat the module and that will show if there is any failure in the circuitry.

If the two wire pickup col lead that plugs into the back of the module has been pinched when reinstalling the distributor cap (a common happening) you might be getting some arcing. Inspect those two wires carefully and be sure they're out of the way when replacing the cap.

When you set the timing, did you have the jumper wire inserted into the ALDL? Ignition off when inserting and removing the jumper wire?

Edit: Didn't mean to duplicate your answer, Gall. I was writing while you were posting.

[This message has been edited by fierofool (edited 11-17-2017).]

https://www.summitracing.com/parts/dui-000222?seid=srese1&cm_mmc=pla -google-_-shopping-_-srese1-_-davis-unified-ignition&gclid=EAIaIQobChMIhPbJ9_PF1wIVjbrACh0V0QqdEAQYAiABEgIi8_D_BwE

The best ICM I ever had, since I have this one I haven't had any issues.

The terminals on that one aren't configured for the stock Fiero 2.8 harness. It isn't even designed to fit the Fiero distributor. How did you make it work?

When clicking on your link, it goes to Wayfair, then a button for Summit. Clicking on the Summit button gives me a "Warning of Suspicious Activity." Access blocked by one of my apps.

I'm running a cheap-o Welles module in one of my cars and have been for years. After replacing the plugs, wires, and ignition coil and being sure all my grounds were in place, I've had no problems with failures. Prior to that, they didn't last very long. Even the GM brand modules failed very rapidly.

quote Originally posted by fierofool: The terminals on that one aren't configured for the stock Fiero 2.8 harness. It isn't even designed to fit the Fiero distributor. How did you make it work? When clicking on your link, it goes to Wayfair, then a button for Summit. Clicking on the Summit button gives me a "Warning of Suspicious Activity." Access blocked by one of my apps. I'm running a cheap-o Welles module in one of my cars and have been for years. After replacing the plugs, wires, and ignition coil and being sure all my grounds were in place, I've had no problems with failures. Prior to that, they didn't last very long. Even the GM brand modules failed very rapidly.

That is a random picture. If you go to summit you can find the one for the fiero. I bought mine and it was a direct swap.

I just wanted to mention....When swapping the ICM, you can PINCH the wires as you re-install the cap...Be very careful! (That could be your problem...but you would probably notice it...)

@fierofool

"When you set the timing, did you have the jumper wire inserted into the ALDL? Ignition off when inserting and removing the jumper wire? "

Yes we did

We put the modulle in a other Fiero (V6 2.8) and all worked fine, so the module cann't be the problem.
Then we tryed the modulle from the other Fiero (that runs fine) and then the fiero didn't even starts???

Can it be the ignition coil? (there is a spark)

Or what if the ECM is the wrong one, can that be a problem?

One reason why modules don't work is that there is too much resistance in the secondary (hi voltage) ignition. What is different between your 2 cars? Spark Plug wires or ignition coil may be the problem,

[This message has been edited by Gall757 (edited 11-20-2017).]

If you have spark but it won't start, look at the fuel side. Remove the rubber intake tube, spray some starting fluid into the intake and try to start it. If it does, then you have a fuel problem.

Since you're plugging and unplugging the harness to the ICM, you may have dislodged one of the wires in the harness. The larger of the two contains a circuit for the fuel pump. Unplug the 4-wire harness to the ICM. Look at the end to be sure that all 4 terminals are all the way to the front of the plug. If any of them are recessed further into the plug than the others, push it back to the front, hold the harness plug where the wires enter from the back and reinstall.

Just in case you have done what I've done before, I'll ask this question. "Did you forget to reinstall the rotor button?" After a no-start condition, I discovered my rotor button lying in the trunk.

I'm also wondering if you don't have your timing 180 degrees out of time. The # 4 cylinder also shows up on the timing mark, so if you only used the timing mark to do the initial set of the distributor, you can be out of time. Number 1 also comes to top dead center when 4 is on compression. That will cause backfiring and poor running, if the engine will even start.

You can test that by swapping the plug wires at the distributor cap. No need to pull the distributor. Just pull 2 at a time, on opposite sides of the cap and swap places, until you've swapped all 6 to the opposite side. So, you would swap 1 and 4, 2 and 5, 3 and 6.

quote Originally posted by my-fiero: there is a spark

How much of a gap are you testing this spark? Outside of the combustion chamber (at atmospheric pressure), the spark should have no trouble snapping across a 1/4" gap.

@ fierofool
"Did you forget to reinstall the rotor button?"

No, we placed the rotor

"I'm also wondering if you don't have your timing 180 degrees out of time."

No, we checked the #1 cylinder (sparkplug out and put in a screwdriver to feel the posision of the #1 cylinder)
For sure we have tryed 180 degrees, but that was a total no go

What I now go to try is to replace the coil

Setup is now

ACdelco spark plugs (rockauto)
8mm sparkplug wires (fiero store)
MSD rotor/cap (fierostore)
Accel hi performace coil (fierostore) <--- I will change this whit stock coil
Icm Delphi (rockauto) <--- I will change this whit stock icm

The problem seems to be the magnet from the ignition.

I Orderd a CARDONE 841633 (84-1633)

So I hope the problem is fixt then.

Here a movie from the first run on the street (borrowed ignition)

First run on the street

[This message has been edited by my-fiero (edited 11-27-2017).]