I just completed the MPFI swap on a 91 CRX DX w/ automatic transmission. Here are the parts i used:

- 91 si intake manifold, throttle body, fuel rail/injectors, etc.
- 90 si distributor
- 88-89 integra LS automatic transmission ECU
- 91 si injector resistor box

I double checked all the wiring, it started up first try without any codes. HOWEVER:

Once i start the engine, it starts accelerating as if the gas pedal was fully depressed. I tried slackening the throttle cable, adjusting the idle screw, i even removed the throttle cable, and it still accelerated. I just shut the engine off once it hit 6-7000 to prevent any problems. Also, I cannot shift out of park (i dont kno whether its because of the acceleration problem, or because i did not disengage the shift lock solenoid at the ECU).

All vaccuum connections were done with reference to a chilton's manual diagram and were double checked. Almost all hoses were clamped. I'm guessing one of the valves is broken (fast idle control valve maybe?), but i'm not sure what controls that acceleration when i start up the engine.

Any help is appreciated. The car scene isnt big around my area, so i dont have a local mechanic or anyone knowledgeable to help me. Its only me and my suburban garage w/ minimal tools. I really need to get my car back up and running, because school starts in a week and it'd be sad being the only senior riding the bus to school

Again, ANY HELP IS VERY MUCH APPRECIATED!!!

 

Is it throwing any codes? Do you make sure to swap out the wires on the TPS so that it doesn't go to redline when it thinks its at idle.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FourthGenHatch &raquo;</TD></TR><TR><TD CLASS="quote"> Do you make sure to swap out the wires on the TPS so that it doesn't go to redline when it thinks its at idle.
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thats a good one. It just revs up, it doesn't rev up and down?

 

i did switch the wires on the tps.

and yeah, it only revs up.

 

Vaccum leak.... double and then tripple check all of your manifold gaskets.

when I did my mpfi swap, The bracket that goes from the block to the back side of the mani was tweeked up a little, holding the back of the mani too high and not allowing my intake mani gasket to seal properly.... did exactly the same thing that you're describing

 

This sounds like the problem, because coolant is leaking as well, and maybe because the manifold didnt seal properly as you described it.

do i ABSOLUTELY need that bracket in the back? can i just remove it and have the manifold held on by the bots by the runners?

If not, how can adjust the brace so that it doesnt lift it up.

 

it will fit properly if installed after the intake mani is tightened down, I was lazy and just pulled it.... went for about 8000 miles that way, but put it back on when I put my new engine in.

 

you need that bracked because you manifold's heavyest part it tward the rear, try again with out it and see what happens, next with it and see if it works

 

I have always taken that damn bracket off and trown it in the garbage..and never had any problems...toss it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DohcVtecCrx &raquo;</TD></TR><TR><TD CLASS="quote">I have always taken that damn bracket off and trown it in the garbage..and never had any problems...toss it</TD></TR></TABLE>
I was debating doing this as well since I used a Z6 IM on my A6 head/block and that bracket didnt line up right but I decided just to use it what I ended up doing is you know those spacers that go onto the injectors off of the mpfi IM? Well I drilled them out a bit bigger and used them as spacers for that so it wouldnt be pulling it down or anything worked good and I have no leaks.

 

the brace was the problem.

got rid of it, bolted everything back on,
no leaks, no high rev at the beginning, PERFECT.

Thanks a lot for the help everyone.

Still one problem, .. there is a helluva lot of exhaust gas coming out the tailpipe. Anyone have an idea why?

 

yeah i run without the manifold brace, no problems here.

what do you mean by exhaust gas? smoke? is it white? probably coolant i had problems with burning coolant because i didnt have the manifold torqued quite tight enough. it should burn off and quit smoking after a while.

 

yeah, the smoke is white.

when i was trying to find the leak for the coolant, i leaked about half of my jug of coolant spilled out the bottom of the engine bay. i'm assuming i just got a crapload of coolant in the engine and thats why its smoking?

also, i have a cable that was attached to the throttle pulley coming from the transmission. remember, i have an automatic transmission. Do i have to hook that up?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xavierfg &raquo;</TD></TR><TR><TD CLASS="quote">yeah, the smoke is white.</TD></TR></TABLE>

when you had the vacuum leak water went into cylinder #1... if it's running fine now (no missing cylinders) you should be allright. It will smoke for about a week because that coolant is trapped in the exhaust pipe now.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xavierfg &raquo;</TD></TR><TR><TD CLASS="quote">also, i have a cable that was attached to the throttle pulley coming from the transmission. remember, i have an automatic transmission. Do i have to hook that up?</TD></TR></TABLE>

that is your kick-down cable. if you don't hook that up the transmission won't drop in to a lower gear when you "punch it". you'll definately want to hook that up. get a cable from an EX civic auto, it should work for you.