Engine bucking like crazy, only sometimes? (Page 2/3)
Patrick APR 23, 08:26 PM

quote
Originally posted by fierofool:

...and got one for each of my 2 cars.



Now that's being extravagant.
fierofool APR 23, 08:31 PM
Ben2002, since you're somewhat new here, you may not know of the New England Fiero Association (NEFA). Contact Ray Paulk, president at 88GT@FieroPride.com I think he's up in the Lowell, Mass. area, but they have members through all NE states.
Benn2002 APR 23, 11:01 PM

quote
Originally posted by Patrick:

This is the high-priced piece of hardware (with minor modification) that I use to read codes.




May I ask how you use that to read codes? I just need to know where you stick it to read thsm
Patrick APR 23, 11:13 PM

quote
Originally posted by Benn2002:

May I ask how you use that to read codes? I just need to know where you stick it to read them.



Did you not click on the link I supplied earlier? It's all explained there.


quote
Originally posted by Patrick:

Did you try? The trouble codes are stored.
fierofool APR 23, 11:15 PM
Remove the trim plate over the cigarette lighter. On the passenger side, inside the opening you will see the diagnostic terminal. Fold the paper cllip into a U shape and insert the ends into the two lower right terminals. Do this with the ignition off. Also turn the ignition off before removing it.

Once it's inserted into the two terminals, turn the ignition to the RUN position. The Check Engine Soon light will begin to blink 1 time then 2 times. This is code 12 meaning the system is working. It will flash a 12 for a total of 3 times. Then if there are any trouble codes stored, it will flash them 3 times, for example 3 flashes, then 2 flashes = code 32, meaning EGR system fault. Once all trouble codes have been displayed, the system will start again with 12 and repeat all codes 3 times until the ignition is turned off and the jumper paper clip is removed.

The trouble codes are listed at the left of the Pennock's home page, telling you what each number combination identifies. Once you have all the codes written down and identified, you can clear the codes by disconnecting the round connector coming from the terminal box at the battery. Leave it disconnected for about 30 seconds then reconnect it.

Make the repairs identified by the code(s) then restart and drive the car at road speeds for about 10 minutes. The car won't perform well initially until the computer relearns all of its sensors and their input values. If the Check Engine Soon light comes on again, you haven't repaired the issue. Repeat the above procedures.
cebix APR 24, 08:25 AM

quote
Originally posted by fierofool:

Remove the trim plate over the cigarette lighter. On the passenger side, inside the opening you will see the diagnostic terminal. Fold the paper cllip into a U shape and insert the ends into the two lower right terminals. Do this with the ignition off. Also turn the ignition off before removing it.

Once it's inserted into the two terminals, turn the ignition to the RUN position. The Check Engine Soon light will begin to blink 1 time then 2 times. This is code 12 meaning the system is working. It will flash a 12 for a total of 3 times. Then if there are any trouble codes stored, it will flash them 3 times, for example 3 flashes, then 2 flashes = code 32, meaning EGR system fault. Once all trouble codes have been displayed, the system will start again with 12 and repeat all codes 3 times until the ignition is turned off and the jumper paper clip is removed.

The trouble codes are listed at the left of the Pennock's home page, telling you what each number combination identifies. Once you have all the codes written down and identified, you can clear the codes by disconnecting the round connector coming from the terminal box at the battery. Leave it disconnected for about 30 seconds then reconnect it.

Make the repairs identified by the code(s) then restart and drive the car at road speeds for about 10 minutes. The car won't perform well initially until the computer relearns all of its sensors and their input values. If the Check Engine Soon light comes on again, you haven't repaired the issue. Repeat the above procedures.



This reminds me... Do you maybe have a battery disconnect switch?

[This message has been edited by cebix (edited 04-24-2021).]

fierofool APR 24, 08:39 AM
No. I don't see any need for a battery disconnect switch unless there's battery drain and you have an unrepaired problem like fuel pump continues to run, headlight motors continue to run or click, or the like. If it's to create an anti-theft method, unplugging power to the ECM would have the same effect. Just remember that any time power is disconnected, the ECM has to relearn after the car is driven some distance at operating temps and road speeds.

If this is in regards to disconnecting power to the ECM to clear codes, the easy way is as I described. Just unplug the barrel connector that usually hangs in the area just below the positive battery terminal.
cebix APR 24, 09:00 AM

quote
Originally posted by fierofool:

No. I don't see any need for a battery disconnect switch unless there's battery drain and you have an unrepaired problem like fuel pump continues to run, headlight motors continue to run or click, or the like. If it's to create an anti-theft method, unplugging power to the ECM would have the same effect. Just remember that any time power is disconnected, the ECM has to relearn after the car is driven some distance at operating temps and road speeds.

If this is in regards to disconnecting power to the ECM to clear codes, the easy way is as I described. Just unplug the barrel connector that usually hangs in the area just below the positive battery terminal.



What I had in mind that maybe the author was using a disconnect switch everytime he drove. So that would mean every drive was a re-learning procedure for the ECM which might to some extent explain bucking.

EDIT: Oh I see I quoted your post but meant to reply to the topic author.

[This message has been edited by cebix (edited 04-24-2021).]

Benn2002 APR 25, 02:04 AM
So I have an update, I ran the codes, it had code 34 - map sensor. I got a new one, I also was doing the slave at the same time and my clutch line decided to start leaking fluid when I was bleeding it so I ordered a new one from the fiero store, so I can't test it until I get that installed...just my luck. Does anyone have any idea if that could've caused my issues? A faulty map sensor? Seems odd to me.
cebix APR 25, 03:21 AM
In my experience this code points to a vacuum leak, not the sensor itself.