hey guys I am not really new to Hondas, but I am sort of new to engine swaps. I was wondering if anyone knows what parts I should need to complete my swap. I am putting a 91 Si Engine and Transmission into my 91 Base model hatchback. My car was originally a 4 speed manual with none of the factory options. If anyone has any advice for me, it will be much appreciated!

 

pretty sure all u will need si front hubs, si axles, and multipoint conversion and pm6 ecu.

 

did you get a new tranny?

 

yeah all the above and a 40/40 prop valve along with your rear disk brakes...
as far as the interior youll needa make a hole for the sunroof
Si seats rear speaker pods & steering wheel

 

You're going to need the Si ECU or EX sedan ECU (PM6 printed on case), a conversion of your stock engine wiring harness to MPFI spec, MPFI intake manifold, and a MPFI distributor. You can reuse the STD axles; as all have the same inner joints. You will probably want to use the Si exhaust manifold and cat also (or an aftermarket one). The transmission linkage will bolt right up; as should the intake system. If you want to run the Si / DX axles, you will need the matching front spindles. As an alternative, I believe that you can also use EX sedan front spindles and axles to get bigger brakes.

 

Thanks guys i appreciate it. I already have done disc brakes in the rear also =p. So does anyone know how to convert the wiring harness? ideally i wanna just pick up a whole complete Si, but if i cant find one for a good price ill be looking into buying all the stuff seperately.

 

THIS. o/p, search for mpfi swap. it's easy. cut three plugs, extend one, and ad four wires.

 

ALL THESES DUDES ARE CORRECT

 

Another option im looking into is an LS swap out of a DA integra, if i bought a complete integra and mounts to make the engine fit in my car would the rest of the parts from the DA work on my civic?

 

nevermind i found a thread with the info for the LS swap.

 

can you post that link please

 

https://honda-tech.com/forums/all-motor-naturally-aspirated-44/ls-swap-ef-2511862/

 

Hey guys, I recently picked up my donor car. It's a 91 Si, and I have a question about the engine wiring harness. It seems that this Si has an extra plug that connects the underhood harness to the underdash harness, at the passenger side shock tower. My basemodel does not have this plug, what do i do when I swap engines? Here's what the plug looks like:

The square 6 pin plug on the right side is the one I am wondering about.

 

if you're going to use the si engine harness swap over the body harness as well. pnp. much easyer than trying to miss match the two

 

Good ****, I'm doing the same with my 89 standard hatch

So far I have the MPFI swap, cluster, header/exhaust, front lip and the dash clock.

 

I have a complete car with the entire underdash harness, does that mean I have to pull my entire dash off =.="?

 

Actually I just really want to know what that 6 pin connector is for, my shop manual does not tell me what it is actually for. It just says that it goes to the main harness, then when i look upp main harness it says the corresponding connector goes to the engine harness.

 

here let me check my plug since my harness is all apart rn give me a few...

 

Thanks mang, hope to hear back from ya

 

should be for the resistor box that goes behind ds shock tower mpfi needs one dpfi doesn't i found it easyer to mod my cx harness when i put in my dohc zc change dizzy plug add resistor box and 2 extra injectors hybrid honda had a good wright up on it make sure you swap in the swaybars. you might have to change the rear lower control arms if they don't have the hole for the end link (my 90 cx didn't) fair # of parts a differant cx-si good luck enjoy the new power.

 

Thanks for the info, I will be looking into it when I check out that wiring harness again. and yeah I will need to use the rear LCA's for the swaybar.

 

the third plug on the passenger side shock tower is for the reverse light switch (solid green and solid yellow), the red/yellow wire for the iat sensor on the intake manifold, the red/white wire for the coolant temp sensor located under the dizzy, the yellow/green wire is from the fan switch going to the relay, and i believe the white wire goes to the dizzy.

 

Man, you rock! So I checked out the Si's underdash wiring again and pretty much decided that I can snake it in to my STD without taking the dash off(hopefully), but I will have to check them out again to make sure that I can either use the Si's interior fuse panel, or have mine work. And also that the interior Si harness will connect to my rear STD harness. but yeah thats where I'm at now.

 

its rad seein people with the same project on their hands! i got a 91 STD and planned for a project but while i new it had a bad crankshaft i DIDNT know that it bent the valves on the first cylinder so im goin for the whole swap.. got a d16z6 with an a6 head and im currently getting the dpfi to mpfi conversion figured out. its all been a little sketchier than planned but i just need the dizzy, intake mani, and conversion harness!

 

If your car is the same years as the si it will be plug n play. The 88-89 have a slightly smaller plug for the rear harness compared to the 90-91hbs and you have to swap the plug out and ad a second one for the brake lights. You'll see what I'm talking about when you get to doing it. Trus me, it'll be easyer taking out the dash. Its only like seven bolts n some screws. Again the dash harnesses are different between 88-89 vs 90-91. Ok since you have a 91 std it should all be pnp. The sun roof harnesses just unplig from the bodyharness