The Pontiac Fiero
2.5L 4 cylinder
to
3.4L V6 CONVERSION!






Jason's Fiero is a second-owner Fiero with relatively low mileage considering its age (1985). The interior was in perfect shape. Nothing like the other cars that we have seen were the dashboards are chiped, vinyl is warped and the seats are torn. I remember the first time I took a ride in it, The stereo had a White Zombie cassette tape stuck in it. His Fiero was a four cylinder with an automatic transmission.

For years, he drove the Fiero only in the spring and summer months. However the brake lines eventually went out, from having rusted. One of Jasons friends had offered to fix the brake lines for him, but after removal they didn't do anything else. The Fiero sat in the yard for three years, give or take, before being towed to Jason's house and then again to another garage.

Well there was a divorce and some money came about, so Jason, me(Andrew) and Dan (with the help of Tim's garage) started to work on converting Jason's Fiero from the original 2.4L, to a Camaro/Firebird 3.4Liter V6 with a 5 speed Isuzu manual trasnmission.



  • Work started with buying a 3.4L V6 engine from a junk yard in Ravenna Ohio.
  • Then Jason bought a siezed 2.8L, for intake, value covers, fuel rail in Catskill New York.
  • From the donnor engine we would have all the brackets.
  • Jason bought a fly wheel in Akron Ohio. But then had to return it since it was the wrong one.
  • Jason bought flywheel #2, this time the right one.
  • We then found a car with the 5 speed tranny that we needed, but the guys at the junk yard torched all the wires, mounts and cables
  • bought new used shift cables
  • New used tranny mounts.
  • New used rear axles from eBay.
  • New cluch line.
  • New cluch (yes, they broke the cluch!) from the Fiero Store.
  • Bought the correct ECM to match the 2.8 V6 and manual transmission.
  • Cluch pedal and assembly pulled from a junk yard.
  • Cluch master cylinder.
  • 2.8 V6 wiring harness installed by the Fiero Factory.

We started the initial engine work Tim's garage in Cuyahoga Falls. There we put on the intake, and swapped brakes arround. Later we towed the Fiero to my house so that we could work on some of the heavy stuff. As with all 3.4L swaps, we drilled and mounted the starter on the opposite side of the motor. Initially we did try to use the coil pack from the 3.4L motor, but with the original 2.8L ECM, that proved to be to much work. Rather we opted to install the HEI distribitor instead. When the engine assmebly was completed, we did a test run with the engine sitting on the floor, no exshaust just headers. It was awsome. Fire shot out the exshuast headers!

Fiero 3.4L on cradle

Ok so at this point the car is still at my house. We disconected everything on the engine craddle and the engine, then lifted the engine and tranny out using an overhead crane. There is now a foot print on the roof of the car. Both the engine and tranny were pulled up out of the top of the car together at the same time. With the motor and tranny out we pushed the car into the drive way, diconected the subframe and then jacked up the car. Lastly, we removed the subframe with the struts still attactched, then left the car there up on blocks.

Fiero 2.5L removed Fiero on blocks

Back in the garage we mated the 5 speed Isuzu manual transmission to the 3.4L engine and then installed the whole thing to back onto the sub frame. We installed a new Flow Master exhuast system, and new brake rotors from the Fiero Store. With everything on the sub frame we were ready to install it back into the Fiero.



Since the Fiero has no rear tires at this point, to get the car back into the garage, we lowered the back of the car onto a palet jack and rolled it into the garage. Then with the overhead crane, we lifted the Fiero by the strut holes. The crane lifted Jason's Fiero right off the ground! We moved the sub frame and engine assembly underneath and lowered the car down on it. When the Fiero got close to the sub frame, we propped the car up with the jack and removed the cranes chain from the strut mounts. We moved the jack arround to help line up the bolts holes, striped one nut but, everything is in!

Fiero 3.4L engine installed in bay Fiero lifted with hoist Fiero lifted with hoist Fiero lifted with hoist

Now its the tedious task of hooking everything back up. Wires, radiator hoses, pullys, air - conditioning, vacum houses, wire harness, dog bone, ground wires.....

replacing old gas. and ready for testing testing the electrical system Lowering from hoist Fiero brake line installation

Problems? well we had some problems.. For starters, the brakes were not just bad, they were gone! We could not get anyone to work on the brakes for us. After explaining to them about the car, they would just say "its sounds like you guys are capable of fixing them yourselves." I think the quote that still lives with us today : "Brakelines are easy". So we had to replace the brake lines ourselves. The entire brake lines, all the way from the master cylinder to the brake hoses... and it was a bastard all the way! Every single thing had to be replaced and nothing would fit together! It felt like it took 2 weeks and 16 trips to autozone just to get them done. It wasn't "EASY" they just didn't want to do it!


Another problem we ran into is that the axles for the automatic are shorter with smaller CV-Jionts than the axles for the standard transmission. So we had to buy new ones. $270.00 from buckeye autoparts, but we were lucky. We found some used ones for $40.


By far, the biggest problem was in the eletrical system. It turns out that Pontiac installed all of the common wires in each and every Fiero. What I am talking about is the main cable that runs from the engine compartment to the fuse box. So whether or not your fiero came with a standard, automatic, v6 or straight 4, the main wire harness has the wires for it. So, if you want to to change your 4cyl for a V6 well then most of the wires are allready there. That is just one problem. The main harness has three of each colored wire, none of then are labeled. So its a big guessing game! The longest running trouble from this setup was the cold start injector.

One easy part of the conversion was restoring the gas tank. The gas tank was all rusted underneth and the brackets were shot. New brakets were fabricated out of scrap metal, ground and sanded down the rust, and finally treated the tank with rust converter paint. Just like new and ready to install into the Fiero!

Fiero gas tank brackets Fixed Fiero gas tank side old and rusted Fiero 2.5L Gas Tank

Dungeon Studios with like to thank the following for there help in this project:


  • -Jason for paying me to do this
  • -Dad for the use of the garage and equipment
  • -Frankarts repair and service for problem solving with the electronic control module
  • -Dan for helping us remove parts at the junk yard
  • -Danners auto wrecking for the parts that we needed
  • -Auto Zone for acually having one employee that new what we needed (thanks Matt)
  • -The Fiero Store
  • -Mikes junk yard
  • -the Clyde junk yard (the one that covers half the town)
  • -Fiero Sails documentation
  • -Jolt Cola / Monster Energy Drink



Updates...

Since the completion of this project there have been a few alterations to the vehicle:


More to come...

What's next? I still have some items on the to-do list.
  • Fastback conversion
  • Upgrade to F23 Getrag transmission
  • Repaint