The motor starts and runs at a steady idle, no audible misfiring, but there are 3 issues so far (car is an 88 CRX DX):

1. The ECU is throwing a code 9. On the CRX that's a cyl pos error, but I'm using a PG7 ECU from an Integra, I couldn't verify if it's the same. I could have accidently crossed the wires for that sensor, think thats it?

2. It's almost like there's back pressure in the intake. Whenever you tap the gas, there's a small hesitation before it starts revving. When the engine is turned off, the intake exhales for about 2 seconds. I use a generic aftermarket intake with a K&N filter, and the breather line is hooked up.

3. When the gas pedal is pressed, the engine revs like normal, but the turny thing on the throttlebody that the cable attaches to only moves alittle bit. I don't think the cable is tightened properly, but that's due in part to not being able to see it work properly. Moving it by hand works as normal.

The vacuum lines are kind of a mess, but in a previous thread crexer stated that for the most part, it's not vital to have them hooked up. Mixing and matching various hoses also seemed to have no effect, save for messing with the 2 automatic only lines, which changed the idle speed.

It's a miracle I got the engine in, the finer troubleshooting is alittle out of my league.


Modified by Deo at 10:22 PM 7/3/2005

 

welcome to haveing a ZC, i still have the idle problem also, and mine has that same hesitation. I'd love to fix them, but from what others have said its one of those things you just accept and enjoy it in the higher RPMs

 

Im having the same problem as you with the intake exhaling or inhaling when I shut my car off. I dont really think I can accept "Welcome to the world of ZC's" as an answer. There are guys that have really high horsepower ZC and I doubt they got there while having problems. Im curiouse to see if anyone has any answers to these questions.

 

Glad I asked a relevant question

I've made concessions on this swap, but this isn't going to be one of them. I love my snappy throttle response, it was one of the defining characteristics of my car. Combined with a touchy clutch, it also made it tough for my girlfriend to drive, a definite plus.

 

ok ok maybe i was alittle off in my comment. i do plan on fixing it...i don't know if anyone has refered you to http://www.thezcr.com but thats where the majority of the ZC info is kept

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Churched &raquo;</TD></TR><TR><TD CLASS="quote">Im having the same problem as you with the intake exhaling or inhaling when I shut my car off.</TD></TR></TABLE>

I think what you're describing is normal for about any engine with an open air filter.

There is no reason a ZC shouldn't run like stock (or better), if you're having issues, something isn't right. I've probably only installed 5-6 ZC's but they all idled and ran like a stock motor should.

 

What we're talking about is pretty extreme. Take a deep breath and exhale as quickly as you can, that's in the range of what I'm talking about.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Deo &raquo;</TD></TR><TR><TD CLASS="quote">What we're talking about is pretty extreme. Take a deep breath and exhale as quickly as you can, that's in the range of what I'm talking about.</TD></TR></TABLE>

I would say you should JUST be able to hear it inside the car with the windows up... about like that?

 

Pretty much, yea.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Deo &raquo;</TD></TR><TR><TD CLASS="quote">Pretty much, yea.</TD></TR></TABLE>

Ya, thats normal... and it seems on engines that are worn out and tired, the noise is less...

 

you should checl your distrubuter for your code 9 issue. I replaced mine and double checked the wiring and I was good to go! Also the hesitation if its not do to the code 9 more then likley is do to some vaccum lines you mis matched or small leaks...... the zc's great but if you want to avoid burning oil i would recomend changing the head gasket, valve cover gasket, and not brining it up to 7200 all the time, and every other oil change use some engine restore in the silver can looking bottle, at checker or walmart or autozone. Belive its called RESTORE

 

I know this is a poor assumption to make, but the engine looks like it's in pretty top shape. It was an automatic, less likely to have seen spirited use and it's extremely clean.

The chances of me screwing something up durring the install are much more likely than the engine having a problem.

 

Your exhaling issue is perfectly normal and in my opinion is kinda kool.

Perhaps a new cap and rotor is in order for your #2 problem.

And as for the code 9, try replacing your cam postions sensor(cmp) or your crank position senosr(ckp) im not sure which it has.

Your throttle rotor may be loose or the cable is misadjusted

Good luck

 

After playing with it some more and taking a test drive (I was reluctant before), the issue has truly become a real problem. Driving is affected by the lag, you have to be alittle too harsh to keep it from stalling in first gear. Shifts aren't smooth and rev matching is nearly impossible. I took the intake pipe off and the same exhaling is coming from the intake manifold, it also has a constant "breathing", kind of similar to constantly exhaling while keeping your mouth wide open.

I really appreciate everones feedback, but this really is a real problem, not an interesting characteristic.

 

I had this problem doing just a DX to Si swap. The extreme hestitation was due to two wires being swaped at the distributor. I cant remember off hand, but whatever two wires you have to add to the distributor from your dx wiring (CYL position I think), they are swapped. Try switching them and your throttle should be snappy (as long as this is the same problem).

Symptom: It idled fine and all, but when the throttle opend, just lagged for a second and then took off, and slowly at that.

 

Oh yea, and about your two second vacuum sound after shutoff: Its normal. That sound is the vacuum bleeding off from the manifold. You just dont hear it with the stock airbox/silencer.

 

turboEFboy, I think your on the right track here, but I'm not quite sure what sensor your talking about.

On the ZC, there's the usual 2 plugs at the distributor, a 2 pin and a 5 pin, as well as a 2 pin connector at the cyl position sensor, a contraption next to the distributor connected to the exhaust cam. I remember mention of having to switch wires at the distributor, but that was probably one of the MPFI wiring guides I read. The DX to ZC article at Hybrid Honda (which I would assume is correct) mentions nothing but running wires to that sensor on the exhaust cam.

That sensor goes to C1 and C2 on the ECU, and I wouldn't be surprised if I accidently crossed them. I went out and swapped them to test it out, but the problem remains. I couldn't do too much testing, the alternator belt is acting up again and it's 3am here, so I'll have to wait untill tomorrow. It's the 4th no less, I could blow the whole car up and no one would notice.

 

Perhaps you have the CYL pos and one of the other sensors from the dizzy swapped? I know on the dx model, one of those sensors wiring is in place of another sensor on the si, so you have to be sure the right sensor is in the right ecu plug. What about the TPS (throttle position sensor)? Did you be sure to swap the power to it?

 

I also noticed that it's throwing a code 7 as well. I accidently damaged the TPS removing it from a spare intake, so fine adjustment is kind of hard, but aparently it's not working at all if the ECU is complaining. Think that might have something to do with the hesitation?

 

That may very well be it. Did you swap wires 1 and 3 at the TPS plug? You have to do that if your car was a DX.

 

Yea, I swapped them. Does anyone have any idea how the car behaves without the TPS?

 

the car would run like crap, your throttle would open but the computer wouldnt be able to know where the throttle is at. its like the blind leading the blind

 

It was the TPS. We managed to get the car working in a temporary manner, but I still need to put in the new one I'm waiting on in the mail. Still doesn't explain the code 9, but I'll burn that bridge when I get to it.

 

I've got all of the codes taken care of now. A new TPS sensor fixed the code 7 and I traced the code 9 back to poor contact at the ECU pin (be careful not to remove them too many times, they seem to wear out).

But I still have some hesitation. Being gentle with the throttle works fine, but pushing it any further than 1/3 of the way or so it hesitates for a split second. It's alot worse coming off of idle than into the rpm range. It's good enough that I could call it a day, but I really enjoyed having a snappy throttle. Any ideas?

 

try replacing the cap and rotor or the enitre distributor just to cross that off your list. my civic had the same prob and i just replaced those plus spark plug wires and it ran like a dream again