I've got an 85' 4cyl Auto with a blown flexplate I'm pulling to overhaul. I've also got an '84 donor with a 4 speed that I'd like to potentially swap in. I've essentially got all the parts necessary on tap. But is the harness/ecu compatible? What are some of the issues to look out for?

If you wanted, you could just swap ECMs and wiring harnesses, pretty much straight forward.

quote Originally posted by crzyone: If you wanted, you could just swap ECMs and wiring harnesses, pretty much straight forward.

Wrong. You forgot about moving the clutch line (which runs in the same location as the Transmission cooling lines), the master cylinder and the clutch pedal. Not to mention the fact that the brake pedal will need to be swapped as well.. Then, there is the difference in steering columns (Not required, but recommended nonetheless). The Manual column has a small lever to release the key, the auto column has a cable that runs to the shifter that prevents the shifter from being moved to drive without the key, and prevents the key from being removed until the shifter is put back into park.

sorry, I was just talking about The ECM and wiring harness.

You will need all accessories for the swap as well.

The manual ECM will have a shift light feature if you want it.

Thanks guys.

The harness swap would be tough as the '84 looks like it's "hardwired" to the frame. I'm aware of the cables and pedal/slave cylinder woes, I've done some old "pre ecm" cars and it was never a cake walk, but pretty straightforward work. It's all these d*mn wires that get me confused...

I'm still a bit concerned at this point. I've finally separtated the motor from the auto tranny, and sure enough the flexplate is shot at the crank, along with all the bolts (sheared) and the spacer is all galled. I'm reading from previous posts tha the cranks are cross-compatible, but rebuild catalogs list cranks as either manual or auto. Is it OK to go from auto to manual like I've read, or is this only a problem when you go from Manual to auto?
I'd hate to waste another day yanking the manual out of my '84 only to find out that the 'duke won't bolt up...
Any input is welcome - thanks.

You shouldn't have any problems with that. I replaced an engine in my 84/4speed with one from a 84/auto. Just bolted the stick shift flywheel up and put it together with a new clutch.

David
Edited 'cause I can't speeel so good tonight

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His Fiero: 1984 2M4 Coupe

Her Fiero: 1984 2M4 Convertible

[This message has been edited by DPWood (edited 09-06-2003).]

I have a question also...

Could you just leave the manual tranny on the cradle and then just drop THAT cradle and the bolt up the engine, and then just swap the cradles...??? Of course all the extra stuf as well...

SmoothGT!

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That's my intention Smoooth. (Great minds think alike) The cradles "look" the same. The only thing holding off now is that the donor cradle has a set of springs that sit lower by 1". I'm not sure if it's a problem at this point or not.