i got my ECU chipped from xenocron and they did a great job. my problem arose when i went to plug it in my car.

car is a b16a

the base map was redone about 3 times and every time i would go to crank my car with the new map the car would not want to start and if it did it would barely idle.

plug in the stock p30 and it cranks right up.

also we plugged in a p28 and turned the key to ACC which caused Q31 on the p28 ecu to fry. yet i have tried multiple JDM p30's and have had no problems like that ?

The Check Engine Light is on but there is no code. i took it to the dealership and they were not able to find any codes either. so im stuck as to what is wrong

any help would be appreciated.

 

Sounds like either the ecu is bad or the chip/chipping is the problem.

I doubt it would be the chipping because he is generally very good at that.

Did he supply you with a basemap when you got the ecu?

 

he did. and he was kind enough to redo it 3 times. I informed him of my situation and he re burned 3 diff base maps and still no luck.

thats why i started wondering about the CEL light with no code ?

 

It could be a few other things like a capacitor could have went in the ecu.

Do you hear the fuel pump prime when you plug this ecu in and turn the key to the on position?

 

the fuel pump primed on all 3 ecu's.

the p28,the chipped p30, and the stock p30.

q31 is a vtec related capacitor that fried on the p28 so i was gonna say my problem is related to vtec wiring but i don't know if that's a correct diagnoses. and if so how do i go about tracing it.

EDIT:Fail to mention. I had a friend throw on a stock honda map for the chipped p30 and it ran just like it would for a stock p30. but still i wasnt able to tune my car to to crank on the 750cc saturated injectors. instead it ended up in limp mode thus me buying another stock p30.

 

i've seen a few ecus now burn up q31. The cause (everytime i've seen it firsthand) has been the EVAP and IAT sensors electrical connection being switched up. As far as I know the transistor in q31 is for the EVAP or IAT sensor circuitry. I've fixed the burned sensor on a couple of ecus, but on one it burned the board and messed up the traces, so I couldn't fix that one.

2 times now this has happened to tuning ecus of mine, both times were b/c the plugs were switched up, 1 time happened on a car my buddy was wiring up vtec on, he said after he did the vtec wiring, went to start the car and the ecu started smoking.

Did the ecu you had xenocron chip work before he chipped it. I've seen several stock ecus not work properly or at all. Now, anytime I chip an ecu for someone I confirm (by testing in my car) that the ecu actually works before chipping it....this way the customer can't come back and say I messed up their ecu by chipping it.

I'm sure xenocron will help you out here, i'd talk to him instead of making a thread on here.

 

The ecu worked fine before i gave it to him and he has tested it in other cars and it works fine.i know the issue is related to my car. more like my wiring maybe?

you said your buddy's one had the same issue and it was regarding his vtec wiring? what did he do to fix it?

also the IAT sensor was burned out and the CEL was on . Even after replacing it the CEL didnt go away. so maybe my wires are switched up.

I shall look for the EVAP circuitry and see if i have them switched.

 

how would i know if they are switched. what color wires are SUPPOSED to go to the IAT ?

 

Check the ff-squad website for the iat wiring. You may have to do some searching, but I think there is something useful in there-from what I remember...

 

what year car?

 

95 honda civic EX with a JDM b16a motor trans swap

 

thanks for pointing me to that site. found alot of information to my benefit and quite possibly the solution to all this wiring mess.

still tho id like to know if someone had a similar experience and what would cause q31 to burn.

 

well got the time to check the IAT sensor and wires. the sensor is brand new. wires running to the sensor are red and white.



on the other hand according to this pinout, the wires should be red / yellow. so im guessing something is switched and ill have to check everything tomorrow morning or later this weekend.

http://technet.ff-squad.com/wiring.obd1.htm

 

nobody with a similar issue ?