My 4th Fiero, My first 2.8 V6. I have A LOT of questions (Page 2/6)
Patrick MAR 28, 09:31 PM

quote
Originally posted by Curlrup:

Any thoughts on the very very dim tail lights? Almost like there is some resistance somewhere.



Yes, check the harness ground located in the passenger side rear wheel well. You'll need to loosen the plastic wheel well cover to gain access. The ground harness is screwed to the upper frame rail, but it often gets corroded there and the harness then no longer grounds properly.

But hey, you should've known that, as it's the same rear harness that a Duke powered Fiero has.


quote
Originally posted by Curlrup:

My 4th Fiero... Anything Iron Duke I am the master...


[This message has been edited by Patrick (edited 03-28-2021).]

Curlrup MAR 28, 10:21 PM
Yes....I should have....dang it. Ok checking that tomorrow. Thank you thank you. Learning so much.
Notorio MAR 28, 11:06 PM

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Random not connected to anything electrical connector....What is it for?



If you can unwrap the wire loom a bit and clean up the wires you will be able to see what colors the wires are. That should help you identify where it is supposed to go.
Curlrup MAR 29, 07:51 AM
I can do that. Seems odd that a pretty decent size plug is taped up and hanging on the backside of the plenum. I should get a multi meter on the pins to see if there was s voltage.
Curlrup MAR 29, 03:20 PM
Ok....Whew....Yep that ground was loose. I now have tail lights!. Also, amazing how that ground probably helped it run better. It ran better after new vac lines, I also did a quick fix and sprayed the hard vac lines with flex seal. Temp fix just to see if there is improvement by quickly plugging any and all pin holes. Yep , it starts better, runs smoother, less stumble, and no hesitation now. Question though. If it runs for a while, you shut it off, Let it sit for a few minutes, then come back it does not want to start until you try it a few times then it just pops off and purrs like there was no issue. Very strange.

Also mystery plug has been unwrapped please see photos.





Purple/white stripe, and orange is what the wires look like.



Also. My new to me Red SE and Juliet, my 88 Iron Duke Fiero I rebuilt.
Patrick MAR 29, 04:02 PM

quote
Originally posted by Curlrup:

Question though. If it runs for a while, you shut it off, Let it sit for a few minutes, then come back it does not want to start until you try it a few times then it just pops off and purrs like there was no issue. Very strange.



Something that's quite easy to check on the 2.8, but often ignored is fuel pressure. Not only do you want to see what the fuel pressure is while running, but you also want to see how quickly it drops when the fuel pump stops. The pressure should hold steady for quite awhile. If it starts dropping immediately, then perhaps an injector or two is leaking.
Curlrup MAR 29, 06:41 PM
Good thing I have a guage. Ok. Time to check that next. Thank you sir! My 88 iron duke just runs and runs and runs since I rebuilt it. I worked out all of f the kinks. So my trouble shooting skills have lapsed. Coupled with an engine I'm not familiar with and I'm scratching my head a lot.
Curlrup MAR 29, 06:44 PM
Also....it was converted to an R134a A/C system in 2002. Just found the sticker under the hood explaining that. So maybe the mystery plug is A/C related?
reinhart MAR 30, 06:08 AM
I believe the "mystery plug" is for the cold start injector.

The reason there's some confusion on the unplugged tube running along the firewall, is there were two different designs. The early design the metal tube plugged into the intake snorkel. The later design plugged into the side of the air filter canister.

During the recall, if memory serves, the early design snorkel was replaced with a new snorkel that had no inlet for that metal pipe. Thus the pipe was open on either end and didn't need to be capped.

The later design that plugged into the air filter was ignored and not capped off as well even though it fed directly into the filtered side of the air filter canister thus allowing unfiltered air into the engine. For that design, the best way to handle it is to put a rubber cap on the air filter canister in place of the rubber hose that went from the canister to the abandoned metal pipe.

Personally I removed the pipe when I used to have a post-recall Fiero but all of my current Fieros are as they were created Pontiac and remain uncut.
Curlrup MAR 30, 09:12 AM
Interesting. So question. Do I need the cold start injector? I just did some searching and it looks to be something people delete since it's a pain in the arse sometimes. More and more I think that plenum will be coming off to see whats going on under it. My smoke machine is coming next week to hunt down any more vac leaks. Figured with twice as many vac lines as an 88 Iron Duke I needed a way to quickly find vac leaks.

Thanks folks I'm learning a lot here on this motor I have ZERO experience with.