New to Fiero ownership and this one is...interesting (Page 2/2)
nathanninjacube NOV 19, 11:26 AM
She's an 86. 100% was a red car that's been repainted. Although the roof is from a blue 87 GT.
Mike in Sydney NOV 19, 04:10 PM

quote
Originally posted by nathanninjacube:

Its most of the time hard to start cold, starts easier hot, still have to press the gas sometimes hot but have to always press gas and crank for a few seconds cold. Even while hot when putting into gear the engine will often (not always) die. Exhaust smells like gas (however has no cats) and sometimes has unburned fuel smoke (white smoke but smells like gas). Honestly didn’t know there was a cold start injector till now. Used to working on 3800s.



Have you checked all of the vacuum lines? Vacuum issues can affect starting and running.
nathanninjacube NOV 20, 11:13 AM
I haven't taken off the plenum to check the vacuum hoses underneath yet, the hoses I can see outside of it look good.
sleek fiero NOV 20, 11:45 AM
sorry to step in here late. That is a 3100 or 3400 aluminum head engine and probably has different ecu,and maybe no cold start? OK now I see the cold start in the one picture

[This message has been edited by sleek fiero (edited 11-20-2025).]

1985 Fiero GT NOV 20, 12:13 PM

quote
Originally posted by sleek fiero:

sorry to step in here late. That is a 3100 or 3400 aluminum head engine and probably has different ecu,and maybe no cold start? OK now I see the cold start in the one picture




No, as far as I can tell that looks like the stock intake and valve covers, which means the stock iron heads, it's just been stripped down or painted silver instead of red. As far as I know the 3x00 engines intakes prevent a distributor from being used:
82-T/A [At Work] NOV 20, 12:18 PM
This may not be a popular take... but I'm among friends here so I'm totally OK if they disagree with me. But when I see wiring hacked up like that, I often think the best thing to do at that point is to just replace it. And specifically, what I mean by that is actually replacing the ECU and going with a newer engine management system.

There are so many good systems out there now. They're a little expensive, and that's the only real barrier to entry if you want a "complete" kit. The one that I have (which I will end up using), is the FAST EZ EFI 2.0 system. It's designed to upgrade and improve 80s GM technology. It's a completely new system that introduces a much more responsive system, along with a rudimentary "automated" learning. That means that it automatically adjusts everything to ensure an optimal air/fuel ratio. So, you can make upgrades, and it will automatically adjust to take advantage of them. You can still fine tune things if you want to lean out somewhere.

The other alternative is to go with a MegaSquirt (or MicroSquirt). Have safe search on if you're searching in front of a spouse... I get some pretty interesting results that are unintended.


Finally, the nice thing about this generation of GM car, is that the gauge cluster is totally independent of the ECM. This means, almost everything is run off of completely independent sensors that feed directly to the gauge cluster. So, you can replace the engine management system, and keep the parts of the wiring harness that apply to the gauge cluster.


Your only other option really, is to buy replacement wiring harnesses... they are out there (used), but you're going to have to do a lot of repairs. The FAST system already has all the clips and everything for GM engines, so it's perfect in my mind.