I'm currently running a jdm b16 and jdm p30 in a 94 Hatch. I just swapped the jdm intake for a usdm p30 so I could bar the car. After the intake swap my ecu started throwing codes. At first it was IAT and 02 code. Those went away and now it says it's in limp mode. The amazing thing is I have 1st, 2nd, 4th, 5th and it will go into vtec. Doesn't like to go into third. Drives just fine. Another thing is if I reset the ecu the code won't go away. Also radiator fan turns on when the key is in the on position. I recently replaced all the ground wires and negative battery cable, the plugs and wires and the starter and main relay. I have no vacuum leaks.

Jdm b16a with tranny
Jdm p30 ecu
Usdm p30 intake manifold with jdm throttle body. (Yes the throttle body gasket is for the jdm throttle body)
Silverline exhaust.

Any ideas would be appreciated.

Thanks

 

So what are the current codes?

 

Current code is solid cel light. It's in limp mode. But I tested it and vtec engages. Before it gave me a code 1 02 sensor and a code 13 IAT sensor. Everything I try to reset the ecu the code stays.

 

Code 13 is not the IAT code... it is a Barometric Pressure Sensor code... which is found INSIDE the ECU. There is no code to say it is in "limp mode", the engine function will tell you that by the way it is behaving. A solid MIL with no stored codes when the service connector is jumped indicates either an unrecognizable code or a bad ECU. It is most common to see this issue when using a chipped ECU with improper programming on chip or a bad chip itself. Also, make sure the thermostat housing engine harness main ground bundle is clean and properly tightened down.

 

Sorry meant code 10. But now it's solid. I'll check that area. Ecu isn't chipped. When I bought the motor I got the whole front end of the car. Literally! The only thing I did was swap the intake manifold and then it went crazy. I took it to a shop and the made a gasket for the jdm tb so I could use that with the usdm p30 throttle body.

 

Sounds like you maybe have swapped around some connectors and possibly shorted the ECU. The most common are intake air temp, idle air control valve and Evap purge. They are round 2 wire connectors. Just to confirm, your check engine light is solid and on while driving?

 

Yeah the cel is solid. Map is on the firewall. I never unplugged that. Iat is on the runner of the intake that one I know is right. I looked into that already. Also I started disconnecting the sensors one by one to see if any of them were an issue since my radiator fan turns on when the key is in the on position.

 

Your IAT and EVAP purge are located very close to each other. It's easy to mix them up. As mentioned previously, this may have occurred and damaged the ECU. What wire colors are going to each sensor's plugs?

On the fan, check the two pin sensor on your thermostat housing. Follow the harness back as far as it'll go and make sure it's not pinched. If this wire is pinched or damaged in any way and the two wires end up shorting to each other, the fans will stay on whenever the key is on.

 

I never had to disconnect the evap purge it was tied to the firewall. I will check the wires though. Would it be best to go through and unplug all sensors and clear the code then plug each one in one by one. I appreciate the help.

 

It would be best to check and verify each sensor's wire color and match it up to appropriate sensor. Once verify, even if it "look" OK. That don't mean its OK.. Check and compare to FSM..

 

I'll try that thanks.