1991 civic 4 door DPFI to MPFI

[J89EF9]

Hey guys i just bought it yesterday its a 91 dx 4 door i got it for 400 its really clean but it has a problem someone did (tried to do) the mpfi convertion and messed it up the car runs but it only revs up to 3000 rpm and the check engine light its on i dunno if thats normal.. the guy said it only needed and Si dizzy but i checked the wires from the ECU and it doesnt look like right because i've read the dpfi mpfi article a few times and i think the wires on the car are messed up
so i dont know..
if anyone has had the same problem before or has any idea of what could be the problem please let me know i would really apreciate it cuz i need to smog the car to put it on my name so i dont have much time

thanks

Juan

 

[wagovanb16man]

1st off, what is your ECU flashing?

 

[Jeef]

If someone else started the conversion start looking for the basics. What ecu does it have, verify it by the number on it? What distributor does it have, verify with pictures and the amount of wires coming off of it. Does it have the resistor box installed? There are 4 injectors and the mpfi manifold is on it right? I did this over 6 years ago so there might be some other stuff I missed but check to see if all the parts are right first. Also check the basic tune up stuff cap, rotor, plugs, wires, etc. If all that checks out, then start with the wiring check every single wire that has to be changed to make sure its in the correct spot and that the wires are loose. I highly recommend soldering the wires if it hasn't been done already. Just twisting the wires is not good enough, trust me on this. If that checks out start looking into seeing if you have a bad ecu, injectors, resistors box, ect.

 

[J89EF9]

1st off, what is your ECU flashing?

it is flashing codes 4 CKP Sensor (Crankshaft Position Sensor), 6 ECT Sensor (Engine CoolantTemperature) and 10 IAT Sensor (Intake Air Temperature)

the ECU its from an 89 CRX si (PM6), it has the resistor box installed, the manifold with the injectors, about the dizzy i dont know if i have the right one is there any number on it or how can i tell if its an si or a dx one? i took some pictures of it..
thanks for the replies

 

[Jeef]

I forgot exactly how to tell but does the wiring to the distributor look like its been changed? The plugs are different between the si and dx distributor so if its the si the wiring has to have been changed somewhere for it.

 

[J89EF9]

yeah i cheked my hatch's distributor ans its different so i guess i do have an si one and since i have all the parts i need im just gonna get some extra wire and re do the whole wiring.. cuz i think the car has the Si harness but the wires at the ECU dont match its so confusing =S so im just gonna get some extra wires and run the wires to each injector, the distributor, and the resistor box.. i will use this diagram as a guide

 

[J89EF9]

ok i think i found the problem.. i re did the whole wiring i run a wire for each injector, the 2 wires for the distributor, and one for the resistor box.. one of the codes its gone but i still have code 6, and 10 flashing.. so i just found out that the guy who did the swap used the whole si harness which i heard its not right.. so imma get a dx one and do the whole thing again =\ and if it still wont work and just gonna sell it to the junk yard >=(..

thanks for reading

 

[J89EF9]

it wont start =(.. i changed the si harness to a DX one plugged everything right re did the wiring from the ecu and all my codes are gone =D thats the only good thing.. everything looks aiight but when i tried to start it i would just crank =(..

any ideas on what could be wrong?

 

[Jeef]

Start rechecking the wiring one step at a time. Check to see if it has fuel and spark.

 

[J89EF9]

ok im bringing this old thread back..
like i said before i bought this sedan for 400 with a bad mpfi convertion i tried to redo it without any luck lol.. i had this car sittin in my garage for about 2 months.. two weeks ago my other civic ( 89 hatchback) got stolen.. i got it back 2 days later all stripped and wrecked on the front not driveable.. so i need to get the other one running i had a mechanic take a look at it he said the head was bad.. so i got an engine from a friend for 100 bucks it was a d15 with an si head.. i swapped the head on my old block everything was done by a mechanic so im pretty sure it was done right.. but i cant get it runnin bcuz of the mpfi convertion i have code 16 flashing fuel injector system any ideas on what to look for? i would be redoin my wiring tomorrow morning..

should i get new injectors just in case?
please i need this car to go to work =(

 

[D15Beater]

In case this guy never got the answers he was looking for.... Theres two ways to do a MPFi conversion. One you can hack up your dx harness like someone has done or two, you can swap the whole dash and engine harness. Regardless of what anyone says the whole harness isnt that bad and can be done in 2 hours or so. This way you know you wont have to worry about splices and have the problems youre having now. This is the best route. Using the dx harness works too. If I were you i would take everything added apart and start from scratch. Tracking down a problem that someone else did just sucks. When i did my mpfi swap i used a seperate harness for the for injectors then ran it like a subharness, this is pinned rite into the ecu slots. I also added the bl/g and bl/y wires to the distributor directly from the ecu to the dizzy, these are run with the injector subharness. I do have splices, and do want to swap dash/engine bay harnesses as soon as i locate a wreck crx parts car to swap the crx dash in my four door. This again being the best route imo. You can do it rite or do it fast....which in my case rewiring my dx harness took longer than swapping my buys whole dash and harness out. You decide, but either way you should start all over with the wiring.