i need help on my dx to si swap

[hondacivicguy05]

ok heres my problem i finally got all my swap done. but i got a problem with it now. when i put it in gear and start to let off the clutch and push the accelerator it starts to skip and studdard and it almost stalls out. and i got to looking i have an extra plug left. i think it goes to a vaccum valve that was on back of the dx throttle body. am i missing that valve for the si intake. and is that what could be causing my problem. i gladly appreciate all the help you can give me thanks.

 

[efhondakid]

There will be two or three plugs (depending on the year) left over after the swap. Did you switch the wires at the TPS? CEL?

 

[hondacivicguy05]

yeah i swapped the two outside wires around and i double checked my other plugs i had to make longer and they are right and my car is a 91 civic if that helps any

 

[efhondakid]

Is it throwing any codes?

 

[hondacivicguy05]

none i have sat there and watched it for like 5 or 10 mins while it was running and its not giving anything i even checked my vaccum lines to make sure they are right but all i can figure out is i'm missing a vaccum valve off the back of the intake that i have seen on another si intake like the one i used but i'm not for sure if that is the problem or not

 

[efhondakid]

Take a pic of said missing part.

 

[hondacivicguy05]

ok i will but it might be a day or so before i can get it up on here and i will also take a pic of the intake i got on there also

 

[jlicrx]

you should have one extra connector left over on the DPFI harness - white 2-wire connector with orange and black/yellow wires - that connector went to the Tandem Control Valve on the back of the throttle body - the MPFI doesn't use a Tandem Control Valve - the 89-91 Si intake manifold has a Fast Idle Control Valve on the back side (picture below) - the 88 Si did not have the Fast Idle Control Valve - the DPFI car does not have any wiring in the chassis or engine harnesses for the FICV - the FICV only works when the ambient air temperature is below -10C (14F) and just bumps the idle up slightly - the car will run just fine without the FICV

 

[hondacivicguy05]

ok so i can tape that wire up and tuck it in the wire harness out of the way so thats got that solved but i still got the other problem of it cutting out when i start to take off and it starting to run like crap when its sittin there at idle and thanx for the help so far

 

[hondacivicguy05]

pics of the intake i used

 

[hondacivicguy05]

i think i finally figured out what is wrong with my car i think its between my throttle body and my injectors are working right so i'm goin to change them out and see what that does

 

[mikey bottles]

a good friend of mine just recentely told me he had, what sounds like, the same problem when he did his swap before, his problem ended up being that he had to run the crank angle sensor wires, and the fuel injector wires through different holes in the firewall otherwise they were interfering with each other. He said after he ran them seperately he never had any problems with it.. hope that helps.

 

[hondacivicguy05]

ok i will try that and see if that helps thanks for the help

 

[hondacivicguy05]

i tried it and it didn't make any difference in it still does it so i guess i'm goin to go ahead and swap out the throttle body and the injectors then again it might be one of my injectors are messed up so i'm goin to go ahead and dothat since i have a guy goin to give me the parts

 

[hondacivicguy05]

i change the injectors and it still does it can it be possible that i'm not gettin enough fuel and that would make it run like crap when i try to go down the road

 

[Fernpatch]

I had a problem like that with my swapped crx when I first started it. In my case I had the wrong plug on the EACV. Thankfully my computer set a trouble code that steered me in that direction. Check the wires going to the EACV. Depending on your harness there are 3 or 4 plugs that will clip into the thing and only one will work right. You need a white plug with a black/yellow and a orange(or brownish) wire. hope this helps.

 

[prpprimo]

Im thinking intake leak. Did you use a new(OEM ) intake gasket when you installed the intake ? Your describing a stumble during acceleration. Here is a cheap an easy test. Grab a can of carb cleaner or starting fluid. While the engine is running, spray directly where the intake mounts to the head. If your RPMs increase you have a leak, and if no change I would check your fuel pressure regulator, sounds like your running lean, which an intake leak would cause. Air/fuel mixture.

Another possibility is a faulty o2 sensor. ..its process of elimination at this point. Be sure to post your results.

 

[hondacivicguy05]

thanks for the help i'm goin to go try it as soon as i can i hope that something works so i will let yall know if it works or not and i did use a new intake gasket when i installed it

 

[hondacivicguy05]

ok heres an up date i checked to intake to see if it had a leak and its ok and as far as the white plug i had the wrong one on there and i change it cause i had the wrong one on there and it keeps giving me the code for that but if i wire it back like i had it and reset the ecu it don't give me that code so i guess i'm goin to change the regulator and try that

 

[hondacivicguy05]

ok another update i change the plugs in it and put some for the si in it and it made it run alil better but still has alil skip in it so i'm goin to change the plug wires and try it and see if it clears the problem out