Today I went and looked at a crx with a B16a swap, The problem is that the car runs really rich, could this problem be with the harness? What harness should be used when doing this swap? The car also has a fuel pressure regulator but that didnt help to lean out the mixture. Any help on this would be a[preciated

 

Need a better description of the problem... do you mean it idles rich, runs rich?

The harness used should be the stock CRX harness with a couple more wires added.

My B16A does this too. It never runs stoich.

 

The car idles rich you can smell gas fumes. also the car runs rich also, the idle is not steady also. The vtec solonoid is not connected because the connecters broke during the shipping of the motor, could this have something to due with it? The car throws a cel also, i didnt get a chance to see what the code is.

 

If the solenoid isn't connected that'll throw an immediate CEL, which will also put the car into limp mode (meaning it'll ignore all the sensors). If it's running rich to the point where you can smell gas fumes, that's scary... but yeah, the solenoid might have something to do with that.

 

I know what it is

I bet the car is a DX.
DX MAP (Manifold Absolute Pressure) sensors are not the right type
for MPFI (Multy Port Fuel Injected) engines like the B16.

To get the engine to run right you need a MAP sensor from something like
a 92 and up Civic or 90 and up Integra or a 88-91 CRX/Civic Si

George

 

Good call!

 

I just inspected the car more. The swap was done but the guy used a 95 b18 header with one o2 sensor in the cat and the second one is just hanging, could this be the problem of the rich fuel mixture, On my 95 gsr my o2 sensor connector came undone and i threw a cel light and my car ran really rich.

 

I don't think a B18 header will even bolt up right. The correct header is a USDM B16A2 (del Sol VTEC).... .

Anyway, on my car I don't even have the O2 sensors plugged into the ECU and it's not running that rich.

Did you check if it was a DX?

 

it's a 91 si

 

B18 header will bolt up fine. The bolt pattern on the heads is the same. I'd check the MAP sensor.


[Modified by 97TypeR_9, 10:06 AM 7/24/2001]

 

If you are using either a PWO or PR3 ecu you MUSt have both O2 sensors connected to the ECU in order to get the right air/fuel mixture.
Other wise the engine will run in limp mode which means that it will run super rich, to protect itself from runing lean which could destroy the engine.

Also, the O2 sensors need to be close to the head in order to work correctly.
The O2 sensors you have are one wire O2 sensors which are not heated, so they need to be close to the head to reach optimum working temperature.

That's the problem you have.

I have done a whole bunch of swaps on Civics, integras and CRXs and I have fixed a lot of swaps other people started, they all screw up with the O2 sensors.

George

 

Y'know, I thought the same thing about the O2 sensors. If you disconnect them it'll throw a code and put you in limp mode. Fact of the matter is, not every problem causes a limp mode... the O2 sensors on the PR3 and PW0 ECUs happen to be one of those problems which will not cause a limp mode (though it will throw a code and cause a CEL).

Trust me. I'm doing this right now... no limp mode, only an intermittent CEL (it goes away when the car's shut off, and sometimes comes on when you're driving). If you don't believe me take a look at the post in the Hybrid section by elusiveracing23... who is also running a B16A with no O2 sensors.

It's not like we came up with this solution by ourselves. Derek from Hondata originally posted this as a solution to a problem we were having. I didn't believe him either until I tried it out and it worked.

Link to elusiveracing23's thread: https://honda-tech.com/zerothread?id=54328

Link to Hondata's thread: https://honda-tech.com/zerothread?id=50722

The latter is an interesting read .


[Modified by raeneshadow, 8:50 PM 7/24/2001]

 

the O2 sensor has nothing to do with your feul and your car running rich. if you car is running rich, like he said, check your map sensor. but with the map sensor when many people do swaps the usually keep the original sensor. if you smell gas when starting your car or running. its your ecu. try someones ecu on. sometimes people like to increase more than usual gas to be injected into the injectors. causing the car to run much faster. if by any chance thats not the problem wiring is messed up. and usually on the si for a swap. there should be only 4 wires that is install for a b16a swap. check those 4 wires and any other wires cut. those 4 wires should not be cut, they should have pins to like the other pins. its the vtec selinoid, 2nd O2 sensor, knock sensor, and oil pressure.