Crx W/ B16

[b18c1civic97]

I'm assuming this is the right location, but if its not, please move to appropriate place. Ok I have a 1990 crx hf with a b16a and a pr3 mugen chipped ecu. The car has ctr cams, intake/header/exhaust. The first problem I notice is the car idles between 2200-2700 rpm always, doesn't really affect how the car performs but its a little annoying. Any ideas what thats about? My main concern is that I was driving pretty hard the other day, and the highest I usually rev it up to is 8500 rpm with no problem. But I got the chance to run against a carrera 4, and thought it would be fun to see how my car compared to his, but when I punched the gas it felt a little more sluggish than usual, and at 7000 rpm, the engine sounded as if I was reaching a rev limiter. When I checked the ecu, a code 6 appeared, which is the TW sensor. I checked the sensor, and the wiring leading up to the sensor, and could not find any flaws. I don't think its the sensor because the code doesn't come on all the time, and it doesn't come on consistently when I drive the car hard. Any ideas what this could be? The last issue I had is that whenever I put the car in reverse, the tach drops to zero for some reason, I'm guessing a short in the reverse lights, but any suggestions would be greatly appreciated. Please leave me anything I should check because I will be checking all this stuff this weekend, so if anybody has any heads up, I would be thankful, thanks in advance.

 

[radnulb]

did you do the additional wiring changes for HF cars? HFs have 3 additional wires that Si lack. One of them is a wire connected to the reverse switch that will cause odd codes and behavior in reverse if left connected. I'm in Norfolk, VA away from all my notes otherwise I'd tell you what pin it is, but you could easily figure it out from looking at a pinout. 99% sure they are 3 adjacent pins on the "B" connector.

As for your car idling like ass, welcome to the Mugen chip. The PR3 mugen chip is more of a mess than any other I've seen - my homefry ran his LS-vtec w/ CTR cams with that chip and it was still running quite rich across the board. Horrible chip - also disables most diagnostic functions.

Sensors do go bad. Try swapping the coolant temp sensor with the one from your HF motor. it is the one wire one kinda by the distributor on the head NOT the two wire one. Having a code for this will definately cause your ECU to go into a safety mode, which appears to be what you described.

You're a fool to rev that motor above 8100 RPMs (even with CTR cams) unless you've also replaced valvesprings. B16A1 valvesprings are notorious for floating valves with high RPM abuse.

Good luck.

 

[b18c1civic97]

valvesprings were replaced, forgot to mention that. What chip would you suggest to use for the motor then? Thanks for the advice.

 

[radnulb]

no cookie cutter chip will work well. get it tuned right if that's what you want.

 

[b18c1civic97]

Ok finally got the problems fixed, and if anybody has the same problems again in the future, hope this helps.

Idle was way to high.

The idle was reaching up as high as 3750 rpms, and was driving me crazy, on dragva.com somebody told me to pull the intake off and plug the bottom port inside the throttle body, when I did this the rpms dropped immediately to 750, so I went ahead and just plugged it up with a big ball of electrical tape. If you decide to do this rather than replace, make sure you plug it up well enough that it would get sucked into the port or through the throttle body, I haven't had problems since.

Whenever I put the car to reverse, the car would act funny and the tach would drop to zero and lights would flicker and car would like it was buggling.

This problem actually was what was giving me the code six. If you go to your ecu, and pull out B plug, look for a Green/black wire B9 (this is only for the crx hf, as the crx si does not have this wire.) Just cut it and reset your computer, no more code six, and the car will run normal from there on.

Thanks to the people on here that helped me out.

 

[radnulb]

you should PM customabrik8 on dragva - he's a buddy of mine and pretty knowledgeable about electronics and tuning. If you wanna get into tuning that thing yourself, BRE + Turboedit both have basic PR3 support.