Hi all! i have a 1991 honda civic SI and my engine was smoking! so i bought a new engine from the auto wrekers and they gave me a CRX engine...so i installed the crx engine and now when i start the car it turns off on me unless i gave it gas but when i let go of the gas it turns off! i tried driving the car but it keeps on choking like it wasnt getting enough gas, it starts hoping back and forth when its under 4000 rpm but when its over 4000 rpm it runs fine! and it says check engine on the cluster! so im guessing its the computer or something it might not be compatible with the new engine or a sensor thats messed up in the new engine! what do u guys think? thanks alot

 

check your codes on the little flashing light on the ecu, count the flashes, then look in FAQ to see what code you have. also might want to do a compression test. sounds like you might have bent valves. where did the motor come from?

 

Check your TPS


"it starts hoping back and forth when its under 4000 rpm but when its over 4000 rpm it runs fine"

 

tps?

 

throttle position sensor

 

throttle position sensor : In short tells the ECU how open or closed your throttle is. In which tells the ecu to add more or less gas.

 

As Carpernter said already, you need to check those codes first, there is a reason why the light is flashing...

 

"As Carpernter said already, you need to check those codes first, there is a reason why the light is flashing..."

I thought they only danced to the beat of the music. J/k . Do what Carpenrnter said first. Me of all people should have made a strong case to check the code(s).

 

sorry guys if this is a stupid question but dont i need a special tool to check the codes on the ecu?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hardcorelolo &raquo;</TD></TR><TR><TD CLASS="quote">sorry guys if this is a stupid question but dont i need a special tool to check the codes on the ecu?</TD></TR></TABLE>

nah, jus pull back the carpet on the passenger side kick panel. you will see a flashing red LED on the ECU and all you have to do is count how many times the light blinks between pauses.

 

Ok i did that and i got the ecu codes as 6, 9, 10, and 14

6 = ECT Sensor (Engine Coolant Temperature) defective circuit or unplugged / defective sensor

9 =CYP Sensor (Cylinder) defective circuit or unplugged / defective sensor
* invalid code for throttle body injection Hondas
** invalid code for V6 engines

10 = IAT Sensor (Intake Air Temperature) defective circuit or unplugged / defective sensor

14 = IAC Valve (Idle Air Control) defective circuit or unplugged / defective sensor

im not sure where those sensors are located on the engine so i can check if their conected right! anyone know?