Comments for Fiero 3.4 F-Body Engine Conversion

Comment on 3.4 ENGINE INSTALLATION by Administrator

Administrator — Thu, 09 Oct 2008 17:54:56 +0000

You have to transfer the 3.4 balancer. The 2.8 damper is tuned differently.

The 3.4 will run lean on the 2.8′s 15# injectors, and the 17#’s are just right but the programming in the ECM is a litle off. You can try to compensate for this with an adjustable fuel pressure regulator, or I’ve heard you can use a quarter in the stock one. But it sounds like if you’re getting soot that you have a bad catalytic converter.

Never heard of the lower intake gasket being a problem, did you replace it with a new one or reuse the old one?

Comment on 3.4 ENGINE INSTALLATION by Bill Hall

Bill Hall — Sun, 02 Sep 2007 03:10:11 +0000

Good article, I did this swap around five years ago, was real impressed with the differance in power and tourqe for the price. I did see the part about useing the 3.4 harmonic balancer, I reused the 2.8 because i was told that the only thing that mattered was the flywheel. The engine has had a barely noticeable vibration at idle, could that be the cause? I used the original injectors at first but it wanted to run lean, and even turned on the check engine light on. I replaced the oxygen sensor, same problem. So I put the injectors from the 3.4 in the car wouldn’t run when I first started it. The more I ran it the better it ran, but I still have the problem of it running rich when it cold, as soon as it gets to normal operating temp it runs normal. I was told that the ecm wasn’t designed to run with the disk injectors that where used in the firebird, but I,m not sure what I can get a set of pintal injectors from that will keep the fuel mixture in the right range at all tempetures.
I had one person tell me to use injectors from a pontiac grand am with a 3.4, and had another tell me to use stock ford 5.0 injectors, cause there so cheap and easy to find. I also have had the problem of the lower intake gasket blowing out around the coolant passage, when I inspected the gasket it looks as if something ate at the gasket, the car had clean coolant, only in the car a year, so the acid contant souldn’t have been a issue. Any help on any of these problems would be greatly appreated, especially on the injectors, im sure getting tired of scubing the soot off of the rear bumper.

Comment on 3.4 ENGINE INSTALLATION by Administrator

Administrator — Thu, 05 Oct 2006 17:20:04 +0000

Good suggestions Brian, I’ve updated the page to incorporate them.

Comment on 3.4 ENGINE INSTALLATION by Brian Manke

Brian Manke — Thu, 05 Oct 2006 03:16:25 +0000

This article helped me out tremendously. I have never done anything of this magnitude and my project turned out almost perfect. You really can’t beleive how good it runs with the 3.4 block. I did learn a few things the hard way- Be sure all of your block is CLEAN including the oil galleys!! I suspect my water damaged junk yard engine was not properly cleaned afer I rebuilt it and promptly trashed the lower end in 75 miles. Rebuild number two and a properly cleaned block and a primed oil pump yielded perfect results. Tip for priming the oil pump – take both oil pump drives and join them with a piece of fuel line. Hook one end up to a drill and it will allow you to fill all the oil galleys before starting the engine. Also be very, very careful reinstalling the cold start injector fuel line. My o-ring got damaged and I almost burned my car to the ground on it’s maiden voyage after the second rebuild. Other than that, the project went great. Hope that helps!

Brian Manke

Comment on 3.4 ENGINE INSTALLATION by Administrator

Administrator — Mon, 07 Aug 2006 17:18:20 +0000

Pedro,
You can use the Getrag 5-speed with this engine in the Fiero. I have done it personally on my own car and there are no issues. In fact, it is easier than the automatic because you don’t have to chop the block “wing” opposite the starter. The statement from GMPP that says, “This engine does not have a clutch boss on the side of the block for standard transmission application” refers to a missing boss for an S-10 manual transmission. It is not necessary for the Fiero’s manual transaxle.

– Update, 10/9/06: Upon reviewing Tony’s fierosound.com site, he is using an entirely different version of the 3.4 known as the 3400, which is a much more advanced engine and a much more involved conversion for a Fiero. The 3.4 referenced on this site is already a good candidate for boost because of its ideal stock compression ratio of 9:1, but it does not need a supercharger. It makes ample low-end torque. Trust me on this, I’ve been driving mine for five years now. A turbocharger is a much better choice for this engine, because it doesn’t breathe well above 4500rpm on its own and would benefit greatly from turbo boost more so than SC boost. A supercharger would do more to increase torque where it doesn’t need it at the expense of your A/C compressor.

Comment on 3.4 ENGINE INSTALLATION by Pedro Roman

Pedro Roman — Mon, 07 Aug 2006 02:09:47 +0000

Hi,
you mentioned on your article that if I want to use a new engine I should go with the GM part number 12363230. I would like to use a 5 speed Getrag with the new engine and transfer all components from the 2.8 to the 3.4 to keep the original look of the car; however, one of the things mentioned on the 3.4 is that it is only for automatic transmissions. Do you know if I could use the 5speed Getrag with this engine and keep the oringinal look of the 2.8? I really would like to do the same that was done by Tony B (see website: fierosound.com) under engine/suppercharged. Thank you very much for your help/time. Pedro