1990 CRX DX. My CRX has auto transmission and dpfi. I have a cable 5 speed out of the same yr and make and all the parts to convert to manual. My auto trans still works alright. And i have a mpfi intake from a B7 along w the dizzy and ECU for auto or manual. Question, which of these two mods will i notice the most gain from in performance? Trying to figure out which to tackle first. Thanks.

 

not even sure i've heard of or would bother working out how to get a MPFI conversion done with an auto trans. I suppose if the Si came with auto... then get that ECU and do a regular DPFI to MPFI otherwise.

auto to manual first then DPFI to MPFI. or both at once. I am happy i did all the wiring in one go. (of course i had a bit more work in also doing a OBD-0 to OBD-1 conversion and adding VTEC)

 

5 spd will be more work, but a lot more performance gain.
if you did dpfi-mpfi first you would need a ps9 auto ecu from the civic ex. not worth imo.

 

I have a PM6 and a PS9. Also have an Si cam from a D16. Im sticking to OBD0. I have the 5 speed pedals and clutch cable already installed but would probably have to pay someone to swap the trans and shifter. On the other hand i could swap an intake but may need help w the soldering/ pinning work. I will probably do the intake first but was wondering which would be worth the trouble for gain most?

 

5spd trans would.

 

When I totaled my first RT4WD Wagon that had a JDM non-VTEC SOHC ZC which is nearly i-damn-dentical to the USDM D16A6, I bought it back from the insurance company (for obvious reasons). The main one being the desire to swap the ZC into my Dad's 1990 DX Hatch AUTO. We played hell finding good solid info for the swap, but DID eventually get it running perfectly. That is the motor that *should* have come in that car from the get-go.

You must use a PS9 OR PM6 Auto (yes, they are out there, I have one). Both of these ECUs were designed to run an MPFI motor w/ automatic transmission.

The wiring is slightly more involved than your typical DPFI-to-MPFI conversion and there is also the issue of the AT Stator Regulator, which is the other cable that attaches to the throttle body cam. I *think* I remember using a cable & bracket from an Auto Accord or Auto EG Civic or perhaps some combination of the two; you can't use the OEM setup. Oh yea, you also need to use an Automatic TB, or drill & tap the A6 throttle body to accept the AT stator regulator cable bracket.

It's quite a bit of work for little return-on-investment (so to speak), but for my Dad and I, it was more of a challenge, more of a "Can it be done?" sort-of drive behind the desire to do so.

Take the above into consideration when deciding what to do first... I think the choice is pretty clear.

 

d.stroy, the PM6 auto is for the RT4WD wagon ONLY from everything I can find.
Do you know if it is completely interchangeable with the PS9?
The PS9 has the lockup solenoid for the auto built into it whereas the RT4WD has a separate box for the trans control.
I'm thinking the RT4WD PM6, auto, is actually the same as the Si PM6, manual, and has no auto control in it.
Can you confirm?

 

Auto or manual I think swapping to mpfi is well worth it for the results aswell as the long term potential.