Question on engine transplant

Vicious · 10:44 AM

alright, so i got a question on the differences in the early engine (83') and the engine i have put in there and am starting to connect everything. the fuel system on my 83 had 2 air valves one aux, and one electric, on the 86 engine there is no air valves for the fuel system but instead a "idle stabilizer".

so how should i go about this i can think of a couple things but i want some input from you guys.

option 1. remove idle stabilizer and replace with the air valve system of the 83.

option 2. rewire the 83 harness to work with the idle stabilizer somehow.

option 3. ????

Also, the 86' has a timing mark sensor which my 83 did not have. all i had was the 2 reference sensors. anyone know if that particular sensor is mandatory for the engine?

Razorback1980 · Razorback1980's Garage

My .02 worth...Probably be easier to stick with the 83 setup.

kdjones2000 · kdjones2000's Garage

The 3rd sensor is there only for factory equipment to detect TDC. It is not needed for operation, and in fact is not connected to anything normally.

If I were you I would get a late AFM and DME for the car. That way you get rid of the stumbling and should have a smoother running engine.

Cheers, Keith

Vicious · 06-15-2009, 02:37 PM

yea i had thought about changing the dme, but its a whole different connection and i really dont want to mess with rewiring that whole thing

914efi · 06-17-2009, 05:45 AM

I am in the process of doing the same swap, but I chose to change everything. If you go that route, I can give details on wiring changes, but it is major work.

The aux air valve for the engine is the old style CIS type, it only needs continuous power fed to it once the engine is running. The other air valve is for when the AC turns on to bump up engine power a bit. If no AC, no second air valve is needed.

If you want the new style idle stabilizer to work, you need everything, late ecu, late afm, late wiring, etc. I have not gotten to the point of seeing how the stabilizer works with the AC, I'm hoping the ecu is smart enough to detect an idle drop and open it a bit since the early AC does not talk through the ecu.

Vicious · 06-17-2009, 10:10 AM

yea, im tryn to avoid replacing all the wiring and what not. not that i wouldnt want to, its just to much work for me to take on right now and i need this car back on the road soon before summer hits. i plan on removing the intake and swappin in the old dual valve system and seeing how everything works. hopefully it all goes as planned today.

while im here anyone have a good way to clean out the fuel tank with it in the car? its been sitting for so long in the heat so im sure theres probly no liquid in it. but id like to flush it out somehow.