can i use the entire wire harness from si (inside car & under hood) to do my mpfi swap?

im pretty sure the under hood harness will work but what about the inside harness. i think it matters what year? and will everything just plug in?
do i need the fuse box?

what exactly do i need to make my car mpfi?

 

Yes you can use the under dash harness as well as the engine harness to make your car MPFI.

It's not recommenced becasue it's a serious pain to do so.
If you go that route you will need to find the same care as yours in a junk yard that was equiped with a MPFI engine. You didn't say what kind of car you have so I can tell you if it's the Si, and take it's going to be an Si, HF or EX.
The only thing you will gain from this is that you will have a completely stock MPFI harness. No big deal.

By far the EASIEST way to go with the MPFI setup is to just convert your existing harness to MPFI spec. There is a bunch of write-up on this.

Here's one of them
http://hybrid2.honda-perf.org/tech/4gdxtozc.html

It's a lot easier than would think. It's only a hand ful of wires and you are done.

Search this forum for everythign you will need to convert your car to MPFI... it's been convered MANY times.

 

I had to use a 91 si engine harness and body harness on my 91 crx std but I had to repin the fuel pump connector Im not shure if other models are the same or not but I first tried an 89 si body harness and it didnt work.

 

DO NOT DO IT, for Gods sake just covert the harness. All I did was see the harness I would have to switch and said **** it. Trust me modify the DPFI harness

 

i modified it and its not running right... im about to give up. i need the car to run cuz im about to loose my job bcuz of this car.

the car runs but then the exhaust manifold starts to glow red and i cant rev pass 2500rpms. im not a mechanic but i can do little stuff.

i dont even mind that i cant rev past 3k but the car overheating makes it undriveable. i need to find out whaats cuzing the manifold to get so hot. im throwing codes 4 and 14.

89hb std..si tranny&ecu

 

your car is in limp mode... you should not be driving it like that. are you getting a check engine light? what code is the ECU blinking? my buddies was in limp mode and it was the repin job we did... make sure they are tight connections.

we need more info to help you.

 

if your exhaust mani is glowing you are running really lean creating too much heat
some where you arent getting the injectors to fire correctly make sure you have the injectors wired to the right pins

(inj1 pin 1) (inj2 pin3) (inj3 pin5)
(inj4 pin7)

 

codes 4 and 14 is what im throwing


RACINTWEEK


11:15 PM 5/27/2004

--------------------------------------------------------------------------------

if your exhaust mani is glowing you are running really lean creating too much heat
some where you arent getting the injectors to fire correctly make sure you have the injectors wired to the right pins
(inj1 pin 1) (inj2 pin3) (inj3 pin5)
(inj4 pin7)

which plug will i find these pins in. if two injectors(the ones you have to rewire when doing the mpfi swap) arent firing would it cause this?

 

not getting proper fuel will cause you to go lean lean conditions cause heat(enough to melt pistons) the connector on left(if your looking at the ecu) when you wired it up you should have already had wires to inj 1&3 you needed to add wires to inj 2&4 and add the wire to the inj resistor (i forget which pin) then take each of the four wires from the resistor and run them to each injector thats it for the injectors


did you switch the wires on the tps?

 

Its really not hard at all , Also i beleive it would be good for someone to do because after you have completed the project you will have a better understanding of how the wiring system in your car works.

Just my thoughts on the matter