ZC Turbo Fuel Management Problem(s)
 

I have a '90 CRX with a ZC 1.6 DOHC, turbo-charged, running about 10psi of boost. ECU is from an Acura Integra, but I'm not sure which one it is (though I can find out if that will help someone answer my question).

Basically I am not getting enough fuel under boost, and I'm running rich at idle. I was fighting with the MAP sensor as it would throw a code under boost, but I overcame that with some modifications to the vacuum lines. I have an aftermarket air/fuel regulator, but as I'm already running rich at idle, I can't really turn it up too much more. I lowered the boost to about 6psi, and the car runs better, but it is still a problem I want to address. At cruising speeds it runs a little rough, but under acceleration or deceleration, it's fine. Currently, it's throwing out an O2 sensor code, however that could be unrelated.

I'm thinking bigger injectors might be the answer (I'm currently using the stock injectors and fuel rail), but am also considering flashing the ECU. Anybody got ideas on a cost-effective solution or do I have to bite the bullet and go get an after-market ECU?

Re:ZC Turbo Fuel Management Problem(s)
 

Hey, man toss the ECU if it is a 88-89 Teg. PITA. Hopefully you have the 1.6l PM6 ecu from before the swap. Go to www.pgmfi.org and You'll find all you need there. can cost anywhere from 20 buck to have someone do it to 150 to be able to create your own set up and be able to tune it the way you want.
The 88-89 teg ECU is re-flashable but it's not easy.
Also see www.turboedit.org

Re:ZC Turbo Fuel Management Problem(s)
 

Thanks man, I'll check into that!!

Re:ZC Turbo Fuel Management Problem(s)
 

Basically, you threw a turbo onto a stock Honda with no fuel/ignition modifications, and expect it to work?

Don't mean to hack at you, bro, but you're lucky if your car still runs. Ask anything you need to in order to get your car straightened out... and don't drive it until you do!

Re:ZC Turbo Fuel Management Problem(s)
 

Yo Mod, I appreciate the concern and friendly advice. I guess I left out a few details. It's not a stock ZC:

J&E Pistons
8.5:1 compression
Forged H-Beam Rods
Precision Balanced to 10k RPM
Mild Port/Bowl/Combustion Chamber Work
Balanced Aluminum Flywheel
Lightened Front Pulley
Stage 2 Clutchmaster Clutch
etc.

I don't think I can blow my motor unless I put some real effort into it.

What do I need to do to run 12psi of boost? Does anybody else have any ideas/suggestions to solve my fuel volume problems under boost?

We've never had detonation. The way we are determining that it needs more fuel under boost is when we turn it up at the air/fuel regulator, it is INSANELY FAST under boost, but won't run anywhere else. LOL.

Re:ZC Turbo Fuel Management Problem(s)
 

I know of two local guys with engine far more built than yours - GE sleeves, Crower rods, and much $bling$ lavished on them - who have chunks out of JE pistons and one of them has a bent Crower rod, all from detonation. They had the same idea - that they were bulletproof - and they had correct engine management systems that cost more than I'd care to spend.

You are running on stock Honda fuel/ignition, meant for naturally aspirated use and nothing else. I repeat my advice not to drive the car until you get what it needs to run without blowing up.

Re:ZC Turbo Fuel Management Problem(s)
 

well, even with those mods on you still have NO fuel/ignition modifications.

Re:ZC Turbo Fuel Management Problem(s)
 

i am about to start my first ZC turbo project everything is fairly straight forward apart from the managment side of things. I had a PM7 ECU but got rid of that as i was told that they were a pain in the ass to chip, i've ended up with a PP5, not sure but think that they are only for uk cars, would i be able to burn a program onto an eeprom with all the settings (boost retard, higher fueling, etc) necessary to run 8psi on 450cc injectors. Apologies for asking the same questions as a lot of people but i'm really finding this confusing as there is so much conflicting information.

Re:ZC Turbo Fuel Management Problem(s)
 

JD is telling the truth. I HAD a dohc zc with a pm6 chipped I with many different tunes. I had 450'cc inhectors all that Jaz and i DID not replace the fuel Pump. NOW i am turboless EXPENSIVE lesson

Re:ZC Turbo Fuel Management Problem(s)
 

Just looking around for a few minutes I can see that JD has lots of experience with this stuff. I'm not taking his advice lightly, but I'm still not so sure I should be all that worried about my ZC blowing up. We took great care rebuilding it and checking piston and rod tolerances, and giving them some extra clearance (before anyone else says it, I know that is all the more reason to listen to JDs and others advice and not run the car). We've already put 3k miles on it with no Fuel Management other than an adjustable air/fuel regulator. Runs great so far, but I am competent enough to realize I do need to do something with fuel management. Just curious if you guys are primarily concerned with detonation being a problem (it hasn't been so far) or if there are other major concerns.

I checked out the sites bumblezc mentioned, they were a great help. I have three ECUs, I'm gonna check them this weekend to see what they are, and see how big of a pain they are to work with. I'm still not sure if I want to delve into modifying the ECU myself. Any other fuel management suggestions? Thanks again!