This is a question

Looking at the wiring diagram for the ignition system of the 3.1 turbo, it appears that all that is required to convert the stock Fiero ECM to DIS (distributorless ignition) is a late model block with a crank sensor along with the other components. According to both diagrams the crank sensor is the only thing missing from the Fiero wiring diagram along with some type of external shield that the sensor wires pass through, all other necessary ingnition wires are present. I have a turbocharged 3400 that has been outfitted with fiero heads and intake and plan to convert to the 3.1 turbo computer at a later date so that I can run the complete 3400 intake system as well and would like to get some preliminaries out of the way. Is there anyone able to confirm or deny my interpretation of such interchangeability?

Although I'm aware of their existence, I did not check to see if there was a sensor on the timing cover as well for when I actually take the next step of converting to the 3.1 computer.

[This message has been edited by Joseph Upson (edited 04-30-2005).]

Most of the wiring is there, but the programming in the computer is not.
Why on earth did you put Fiero heads on a 3400...?

Which computer do you want to use in the end?

The engine is turbocharged, running 10 psi with the cast iron heads as opposed to the aluminum heads that would support 9.5:1 compression is safer. Once I get the time to have aluminum heads machined a little to increase combustion chamber size I will install the original top end and switch to the computer that supports the 3.1 turbo. I still prefer the cast iron heads to aluminum given the number of overheat accidents that I have had without damage resulting. The aluminum heads won't take it. I intend to install a radiator with much greater cooling capacity also at that time.

Thanks for answering my question, I didn't believe it was that easy to switch to DIS

Switching to DIS is pretty easy. The hard part is getting the rest of the Northstar in also.
At least, that is how I plan on switching to DIS.

quote Originally posted by Joseph Upson: Thanks for answering my question, I didn't believe it was that easy to switch to DIS

Ive done it. All It required was a 1227730 computer out of a "93 beretta 3.1" (this computer was in MILLIONS of cars) A lightly modified V6 Fiero harness, witch included some moving around of wires, adding a computer connector and moving some wires over to it. Then replacing the distributor with the DIS pack (same number of wires too!) You have to run a few wires, some for the new EGR, and one for the Knock sensor. You also have to deal with the speedometer, and turn the Fan control wire over to the computer. Having done this, I still have yet to get the car to run "right" My engine is a 3.4 PR. Whats nice about the 1227730, is that it is identicle to the 1227727 TGP computer, but... you can use a 87-88 4 cyl computer bracket to hold it, and it will take the TGP chip, and work just fine. The two connectors that are already on the V6 harness actually fit into two of the three sockets on the 1227730, just that the pinout is very different. Only the Grounds and the Power are in the correct places.

quote Originally posted by Joseph Upson: This is a question Looking at the wiring diagram for the ignition system of the 3.1 turbo, it appears that all that is required to convert the stock Fiero ECM to DIS (distributorless ignition) is a late model block with a crank sensor along with the other components. According to both diagrams the crank sensor is the only thing missing from the Fiero wiring diagram along with some type of external shield that the sensor wires pass through, all other necessary ingnition wires are present. I have a turbocharged 3400 that has been outfitted with fiero heads and intake and plan to convert to the 3.1 turbo computer at a later date so that I can run the complete 3400 intake system as well and would like to get some preliminaries out of the way. Is there anyone able to confirm or deny my interpretation of such interchangeability? Although I'm aware of their existence, I did not check to see if there was a sensor on the timing cover as well for when I actually take the next step of converting to the 3.1 computer.

So can we assume that the 3.1 block is interchangable with the 2.8 Fiero top end? If so...one ends up with a 3.1 seqeuntial injected, DIS that looks like a normal Fiero. (exept for the missing distributor ).

quote Originally posted by Yellow-88: So can we assume that the 3.1 block is interchangable with the 2.8 Fiero top end? If so...one ends up with a 3.1 seqeuntial injected, DIS that looks like a normal Fiero. (exept for the missing distributor ).

The 3.1 block is the same as the Fiero block. The only differences is the hole for the crank sensor, and it may be missing one of the bolt holes for the Fiero's driveline absorber. The pistons in the 3.1 for cars are not interchangeable with the 2.8 Fiero top end. If you used the 93 Beretta ECM, you have a MFI (multiport fuel injection) batch fire DIS. To get SFI (sequential fuel injection) single-fire DIS, you'd need a 3100 ECM. I wouldn't recommend that as the SFI is quite different and programming is an issue. Plus the main reason for SFI is improved emissions and some improvement in fuel economy. It doesn't add any more power by itself.