Fiero has been sitting for years. Would appreciate ideas on how to get it rolling (Page 2/2)
Leprithus SEP 14, 11:37 AM

quote
Originally posted by Cliff Pennock:

The fuel pump works, but does it turn on for a few seconds when you turn the ignition to "On"?



It does, that's how I was originally pumping the fuel out prior to jumping the G port.


quote
Originally posted by Patrick:

Sometimes all it takes to regain a healthy spark is to disconnect and reconnect all ignition component connections, including the pick up coil connection under the distributor cap. This is due to corrosion which has occurred. I apply a dab of dielectric grease to all cleaned-up electrical connections before reconnecting them, in order to prevent corrosion and bad electrical contact down the road.




I picked up an In-Line Spark Checker from Harbor Freight last night. Only tested 3 spark plug lines before it broke (cuz I'm an idiot who grabbed the line instead of the head of the connector and ripped it apart) but on those 3 it did not light up any on any. I disconnected the main plug going into the distributor cap and put a voltage meter on it; it is showing a current. Reconnected it, then used the voltage meter on the individual spark plug lines, which read 0.


quote
Originally posted by theogre:

All say read "codes,"
Did you see replace the battery?
Dead or disconnect battery clears any code.
& ECM won't set new codes either when engine won't start. So...
CEL reading = 12 only
Scanner reports Nothing.




The battery was replaced. I did not attempt to read any codes or jump anything at this time while diagnosing the spark plug issue.


quote
Originally posted by theogre:

Check spark is good but missing ECM won't run injection until see that too.
ECM spark ref & "ground" to ICM are bad or ECM is "dead" then won't run the injection.
You need a Noid Light to tell the injector get pulses.

See https://web.archive.org/web...cast.net/~fierocave/ HE ignition & ground myth notes link to that

& If F-pump doesn't run when turn the key to On only for ~ 2 sec then FP Relay or ECM is "Dead." F-pump may run After you crank a long time to make oil pressure but Oil Sender is often bad too w/ old type sender.

"Dead" ECM can seem to work as CEL turn on w/ key on but 1 or more inputs or outputs can be bad & often not setting codes.

E2A--> If all of that is good, big vac leaks like iffy PB boost line, stuck/dead IAC, other things can make it hard or never start the engine.



Good info all around. Gives me some more to look at, thank you guys. After looking a little more at the distrubor cap and rotor I'm going to start poking around at the hoses and make sure nothing is cracked or a critter didn't find themselves a new home and I just can't see it from the top.

Probably be a couple days before I get another chance to play with it but I'll be sure to update whenever there is one.

Thanks again!
82-T/A [At Work] SEP 14, 11:50 AM

quote
Originally posted by Leprithus:
I picked up an In-Line Spark Checker from Harbor Freight last night. Only tested 3 spark plug lines before it broke (cuz I'm an idiot who grabbed the line instead of the head of the connector and ripped it apart) but on those 3 it did not light up any on any. I disconnected the main plug going into the distributor cap and put a voltage meter on it; it is showing a current. Reconnected it, then used the voltage meter on the individual spark plug lines, which read 0.




Ok, this right here is telling me a few things:

- You have NO power going to the spark plugs
- You HAVE spark going TO the distributor from the ignition coil

I want to make sure what plug we're talking about... I'm not aware of the coil firing without being asked to do so from the ignition control module. So that tells me that the ignition control module is probably good. Can you test to see if you're getting spark from the spark plug leads on the distributor cap itself? (e.g., before it goes to the spark plug wire)? If yes, then that tells me the wires and / or plugs are shot. But if NO, then that would tell me that something else is wrong inside the distributor, like maybe the rotor is missing, or something else.
Vintage-Nut SEP 14, 01:25 PM
If I remember correctly;

Pick-Up Coil to Ignition Control Module (ICM) to ECM to Ignition Coil to Distributor Cap to Distributor Rotor to Ignition Wires to Spark Plugs

To me, remove the Distributor Cap (two screws) to check corrosion on the rotor and cap terminals.

Some Light Reading...

Fiero Ignition Systems
https://www.fierofocus.com/...%20%20Ign%20Sys2.pdf

Edit

Added a Shortcut to Ogre's Cave to help Leprithus's learning curve...

Powertrain / General Engine / HE Ignition
https://web.archive.org/web...t/~fierocave/hei.htm

[This message has been edited by Vintage-Nut (edited 09-14-2023).]

Leprithus SEP 14, 04:03 PM

quote
Originally posted by 82-T/A [At Work]:

Ok, this right here is telling me a few things:

- You have NO power going to the spark plugs
- You HAVE spark going TO the distributor from the ignition coil

I want to make sure what plug we're talking about... I'm not aware of the coil firing without being asked to do so from the ignition control module. So that tells me that the ignition control module is probably good. Can you test to see if you're getting spark from the spark plug leads on the distributor cap itself? (e.g., before it goes to the spark plug wire)? If yes, then that tells me the wires and / or plugs are shot. But if NO, then that would tell me that something else is wrong inside the distributor, like maybe the rotor is missing, or something else.



For clarification here's a picture: https://drive.google.com/fi...09c/view?usp=sharing
It appears there is no power going to the spark plugs but power going into the distributor cap. I had the In-Line tester at the end of the lines (yellow circles) before it broke. I then used a voltage meter in the Green circle plug and there was current. I have not attempted to remove a plug on the cap (Purple circle) yet to test that post. Kiddo was trying to help and got hurt so we had to call it quits.


quote
Originally posted by Vintage-Nut:

If I remember correctly;

Pick-Up Coil to Ignition Control Module (ICM) to ECM to Ignition Coil to Distributor Cap to Distributor Rotor to Ignition Wires to Spark Plugs

To me, remove the Distributor Cap (two screws) to check corrosion on the rotor and cap terminals.

Some Light Reading...

Fiero Ignition Systems
https://www.fierofocus.com/...%20%20Ign%20Sys2.pdf

Edit

Added a Shortcut to Ogre's Cave to help Leprithus's learning curve...

Powertrain / General Engine / HE Ignition
https://web.archive.org/web...t/~fierocave/hei.htm




The more info the merrier. I have a repair manually that led me down this line of thinking as well.

When I have time tomorrow I'll give another update. Thanks for all the info!
Patrick SEP 14, 05:51 PM

quote
Originally posted by Leprithus:

For clarification here's a picture: https://driv...?usp=sharing



You didn't mention you have an aftermarket coil. That complicates things a bit.

When you post images, how about embedding them in you post, using the Upload Media link at the lower left of the message box.




The image file size also needs to be less than 2 MB to display here properly. (Otherwise, a hyperlink icon appears.) I re-compressed your 2.6 MB image.

And 2268x4032 is much larger than necessary. 1080x1920 is plenty big for use in an online post. A smaller image would help contribute to a smaller file size as well.

[This message has been edited by Patrick (edited 09-14-2023).]

theogre SEP 14, 06:13 PM
"Best" spark testers for most cars are basically mod'ed spark plug w/ a clip to ground.
No guessing how to use & puts proper gap to protect the system. Sold under many PN from different sources.
GM FSM & more listed them to test HEI DIS etc.



You never want many testing that jump a random gap.
If the gap is too big, often "fails" because the spark found somewhere easier that often cause some other part to fail. The spark can burn thru plug wire, inside of dist, even coil(s).
If gap is too short then may cause fake result & won't work to spark fuel mix under pressure.
ArthurPeale SEP 15, 11:35 AM

quote
Originally posted by Patrick:

Jumping a spark plug gap of 0.045" at atmospheric pressure means next to nothing. Outside of the combustion chamber, a healthy spark will have no problem snapping across a 1/4" gap.




This is very true - but - you can at least quick-verify that there is any spark, at all.

Weak spark is at least signs of life, zero spark is either they're doing something wrong, or more work is needed to increase it.


That said - since there's zero spark, and if you have an original distributor, the hall effect coil could have become open.

When you crank, do you see the RPM needle move at all? If not, IIRC you could have a bad ICM.
Leprithus SEP 15, 08:14 PM

quote
Originally posted by Patrick:

You didn't mention you have an aftermarket coil. That complicates things a bit.

When you post images, how about embedding them in you post, using the Upload Media link at the lower left of the message box.


The image file size also needs to be less than 2 MB to display here properly. (Otherwise, a hyperlink icon appears.) I re-compressed your 2.6 MB image.

And 2268x4032 is much larger than necessary. 1080x1920 is plenty big for use in an online post. A smaller image would help contribute to a smaller file size as well.




I was trying to figure out why the Link/Image buttons weren't working. Thank you! I wasn't aware it was an aftermarket coil.


quote
Originally posted by theogre:

"Best" spark testers for most cars are basically mod'ed spark plug w/ a clip to ground.
No guessing how to use & puts proper gap to protect the system. Sold under many PN from different sources.
GM FSM & more listed them to test HEI DIS etc.



You never want many testing that jump a random gap.
If the gap is too big, often "fails" because the spark found somewhere easier that often cause some other part to fail. The spark can burn thru plug wire, inside of dist, even coil(s).
If gap is too short then may cause fake result & won't work to spark fuel mix under pressure.



I went ahead and replaced the rotor and distributor cap earlier today. Still does not seem to be sending anything to the spark plug lines. Attempted to start the engine with the cap off to make sure everything was moving correctly. The part the rotor sits on (I'm guessing the distributor, still learning) does rotate although looks quite rusty. Put the cap back on and removed a plug from the cap, hooked to voltage meter and no power was going to any of the 6 ports off the new dist. cap.

I'll try to snag a better picture in the morning of what it looks like under there.
Patrick SEP 15, 08:21 PM

quote
Originally posted by Leprithus:

I was trying to figure out why the Link/Image buttons weren't working.



One other thing I should mention, as this has fooled me a few times... you need to be logged into the forum before trying to upload an image. Otherwise, nothing happens.