Ok i just swapped in my JDM SR20DE and got everything running great except my mother fucking radiator fans won't come on. WTF. I tested the temp sensor ( the one that send the ecu info) with a lighter and the fans came on but when my motor is running the mother fucker won't. So my circuts are good, i replace my thermostae and its good.... i bled the system the best i can and that didn't help...any more sugestions on how to bleed the system and what the problem could be???:( :confused: :confused:

the fan doesnt always come on...only on when the engine is running too hot. you can test it by turning on your AC, keep reving your motor..etc to warm up the motor and see if it comes on.

i understand that...the motor get so hot to where it is overheating...i cna't run my ac cause we had to purge the system and there's no oil in the compressor

Have you checked that the sensor is earthed when mounted? check for continuity between the sensor body (when installed) and the battery negative.

As i said above the sensor circuit is fine i just don't know why it isn't kicking the fans on....

Are you using the sensors from your old motor, or the replacement motor? Just wondering if they might be a little different in their settings. Did you replace ECU as well with one that might have come with the JDM engine, or use you're original one? Something has changed during the swap if it was working ok before, just trying to find out what.

The lighter may have caused the sensor to switch ok but how do you know what temperature it switched at? It may only be working at a temp far above where it should.

Very true...i tested the one on my old motor and the JDM one...the ECU's are the same to my undrstanding. I think their maybe be air in the system which means the sensor isn't coming in contact with the sensor. I'm not sure but all i can say is i have no fucking clue as of right now.:confused:

Originally posted by Blue93G20
Very true...i tested the one on my old motor and the JDM one...the ECU's are the same to my undrstanding. I think their maybe be air in the system which means the sensor isn't coming in contact with the sensor. I'm not sure but all i can say is i have no fucking clue as of right now.:confused:

ECUs are different. But, the sending units are the same (at least the DET sending unit is).

To to http://www.zotz.com and follow the link to procedures and coolant change for instructions on bleeding the head. You're right, the SR20 is extremely sensitive to air in the cooling system.

And I thought I had a potty mouth! :right:

My G20 doesn't have that rear bleeder screw...or does it??? where its located on that motor and all 93 and below SR20's my car doesn't have it. Where is it on the newerset up any clues anyone. I need to get the air out of the system so i can break in my motor and clutch. :D Please help:help: :help:
:bonghitte :bonghitte <----- these guys are hilarious i don't know when i can actually use them in a post but thier awesome:lol2: :lol2:

how do you check the temp sensor?
my fans dont be coming on either!!!!

To check the temp sensor you have to disconnect it from the mounting point on the motor. I'm not positive but it might be laocated in a different spot since yours is a low port. Mine was located under the intake manifold on the passenger side. Its a red pulg and you have to dissconect it and then used a 19mm to get the pulg out.... once the plug is out put it back into the plug harness and heat it witha lighter with the car running or in the on postion....after about 10secs the fan should come on.....:sleep: :sleep:

does the red plug have a clip that goes around it?
cause i own a 94 G and i see a red plug next to the oil filter and it has a clip that goes around it. so you take off the clip unplug the wires get a socket remove the peace thats in the block put it back together and test it with a lighter?

Yeah that sounds like the plug mine was located next to the oil filter also. So just disconnect it and plug it back into the harness and heat it with the lighter and see if the fans kick on. Good luck:D