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Mysterious run/quit issue by kennn
Started on: 05-12-2014 07:02 PM
Replies: 5 (271 views)
Last post by: Jason88Notchie on 05-13-2014 09:43 PM
kennn
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From: Green Valley, AZ USA
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Report this Post05-12-2014 07:02 PM Click Here to See the Profile for kennnClick Here to Email kennnSend a Private Message to kennnEdit/Delete MessageReply w/QuoteDirect Link to This Post
Traveling from AZ to CA this weekend, my Formula's motor would quit running. If I didn't immediately clutch I would get a loud pop/explosion in the exhaust system. Then, as I coasted along I would start the motor and it would run until the next event, which at first was a relatively long interval. However, the intervals progressively got shorter. I stopped at O'Reilly's in Yuma and purchased a coil and ignition module. I installed the coil first with no apparent change in symptoms. Eventually the frequency increased and I pulled over thinking I would replace the ignition module. The connector from the magnetic coil to the ignition module inside the distributor was deteriorated and I couldn't gaurantee a good connection to a new ignition module, so I gave up in the dark and had my car towed the rest of the way to Escondido to a triple A repair shop. The shop (guessed?) that the distributor, plugs and wires would have to be replaced for $1000.00+. They also attached the two wires from the internal coil to the ignition module somewhat temporarily.

So, I said "Thank you very much, I can buy and replace a distributor." So I ordered a reman, A1-Cardone, from O'Reilly's. I t arived with the shaft slightly bent. I ordered another; the bale was missing. I ordered another whose shaft ran smoothly, had all the parts and I installed it. When I went to time it there was no spark. I removed the distributor, and reinstalled the original with the temporary internal module connection and timed it. It ran seemingly well.

The rest of the story is that the symptoms returned.

Any ideas? Thanks, guys (and gals).

Ken

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'88 Formula V6
'88 GT TPI V8

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Playindirty1
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Report this Post05-13-2014 04:25 PM Click Here to See the Profile for Playindirty1Click Here to Email Playindirty1Send a Private Message to Playindirty1Edit/Delete MessageReply w/QuoteDirect Link to This Post
I dont know if this will be much help but i had a 92 cavalier that sounded the same way you mentioned. It was the fuel filter clogged. It gave enough gas to start but then would sputter and stall out down the road due to lack of fuel flow. Fuel filter in my fiero GT was alot easier to change than that cavy too lol. Good luck
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Gall757
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Report this Post05-13-2014 04:44 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
If I have this right, you are using the distributor that you started out with.....so you need to rebuild it with a new magnet and pickup coil. If the primary signal is weak or misses, the result is that backfire thing.....



[This message has been edited by Gall757 (edited 05-13-2014).]

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phonedawgz
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Report this Post05-13-2014 05:06 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
Did you replace the plug wires? Did you replace the coil wire?

The pick up coil receives a signal from the reluctor/magnet in the distributor. When running * the ICM reads that signal and sends the signal to the ECM. The ECM uses that signal to pulse the injectors and after advancing it depending on programming sends it back to the ICM. The ICM receives the signal and fires the coil.

When cranking the ICM doesn't look at the ECM's signal for spark. It instead just passes it through internally until 400 RPM. Then the ECM tells the ICM to allow it to take over the advance.

If the ICM sees the signal drop during operation, the ICM has a fail back function that allows the vehicle to 'limp' home. It then uses it's internal signal directly. When this happens you are supposed to get a check engine light and a code 42. - http://www.fiero.nl/cgi-bin/main.cgi?ECMCodes

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When this trouble happens the ECM clearly is still getting the ignition signal. It keeps on firing the injectors and loads the exhaust system with fuel. That is why you get the pop. So by that it seems clear the primary side of the ignition system is working. The problem must be somewhere starting from the circuitry that generates the advanced timing in the ECM and then forward to the plugs. Since all fail at the same time anything from rotor forward can be eliminated.

Loose connectors on the 4 pin connector are the most likely problem. Look at the White wire specifically
It could be bad pins at the ECM or a bad ECM



The ignition signal is sent from the ICM to the ECM on the Purple/White wire

The ECM applies 5V on the Tan/Black wire when it wants to control timing (over 400 RPM)

The ECM sends the modified (advanced) ignition signal to the ICM on the White wire

The Black wire is grounded at the ECM letting the ICM know it is present.

[This message has been edited by phonedawgz (edited 05-13-2014).]

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Csjag
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Report this Post05-13-2014 09:23 PM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
Do you have a fully functioning and clear catalytic converter?
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Jason88Notchie
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Report this Post05-13-2014 09:43 PM Click Here to See the Profile for Jason88NotchieClick Here to Email Jason88NotchieSend a Private Message to Jason88NotchieEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Csjag:

Do you have a fully functioning and clear catalytic converter?


Ding ding ding...my thought exactly.

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