bandit67

Guys , I put a JDM motor into a 99 for my brother and shortly there after it began throwing code P1337. He replaced the crank sensor twice and it would run abit and then knock off down the road. After I got involved, this site search led me to the answer.......no signal is being given due to JDM oil pumps do not provide a magnetic impulse and thankfully someone posted how to cut, splice and bypass that signal to the ECU. Can someone explain how that CKF system normally functions and exactly what the bypass trick is doing to prevent throwing that code. thanks........

m90polk1

Ckp is used for ignition timing/fuel and reference the cam and cylinder position sensors to make sure everything is running correctly. It's a Hall effect sensor which has a gear on the smaller crank pulley passing a magnetic pickup sending the signal back to the ecu, the ecu is also monitoring the 3 sensors in the dizzy to adjust ignition and fuel. You obviously have a usdm ecu which is why you are getting this code. The cyp which I believe you are connecting the wires for the ckp to, will send out the same signal to the ecu as the ckp would. Both are hall effect, therefore you trick the ecu into thinking everything is good and no code.

94EG8

I'm a little confused as to how he replaced the sensor as the JDM engine doesn't have one or provisions to mount it. You can do it but it requires using a USDM oil pump, timing covers and crank gear.

The ECU looks at the signals the CKF sensor and either the CYP sensor in the distributor and compares them. They should be the same. What the bypass does is feed the CYP signal to both the CYP and CKF pins on the ECU.

bandit67

I got it....thanks, as it has been posted here many times....in order to fix a problem one needs to understand what SHOULD be working in order to solve the problem. The JDM engine I put in does indeed have the drilled and threaded mount required to mount the sensor under the lower cover, right at the timing belt. What we did not know was that the trigger to signal the sensor was mounted on the oil pump and the Asian motors do not have this . I now see what signal we are sending to the ECU to make it think all is well. Would you happen to know about how much voltage is normal on the system....feeding back into the ECU......thanks all.....

m90polk1

should produce and AC current back to the ecu, or you could also use an oscilloscope to monitor it properly. Not sure what the measurement is in ac but for the oscilloscope which is what I use you will have a wave with an offset 0v or 2.5v I believe and it should have a constant wave around the offset. Any abnormalities you would be able to see easier versus a multimeter

bandit67

thanks for the input Guys. We got the crank sensor bypass done and the car fires up and runs and does not throw any cel codes. Problem is, after a few minutes of running fine and getting started down the road, it runs out of power and either dies or almost dies. Cools off a bit and fires right back up and idles fine. When we first got the car running with the new JDM motor , it ran fine every day for about six weeks......then knocked off while on the road. When we got that P1337 code I just figured that was the problem. Now there is another. Question is, when he drove it several weeks prior to doing the bypass could he have damaged the coil or igniter or part of the ignition system that we are now trying to solve. Motors need fuel and fire. to run........so my way of thinking is if the fuel system is working as should , problem must be with ignition somehow. Do the 96-00 Civics have a main relay as the 92-95s do....thanks....

civic402lx

Yes to main relay question. There is a vieo on youtube on the crank no start civic. The poster shows you how to test the coil. You should watch it and see if it will appky to your situation. The poster end bup swapping out the coil because it was bad, not firing. No spark at spark plug.

m90polk1

If he would have damaged it previously he would have had the issue described previously. Are you running JDM or usdm ecu?

bandit67

We are running the stock usdm ECU. Does the fuel rail have a port for hooking up a fuel gauge.. I think the quickest path will be to swap in a known good dizzy and see if things improve. Next will be hook up a external fuel gauge and look for constant or failing fuel pressure. A known good main relay swap may also be in the works. Does that sound like the quickest path to correct troubleshooting.......thanks

94EG8

Swapping in a known good distributor if you have easy access to one is probably the quickest thing you can do. Honestly I think that's where your trouble lies. Sounds like either coil or igniter is failing after it gets hot. The rail doesn't have a port, but there are adapters for hooking up a gauge, that said in all my years of working on Hondas I've never seen a fuel pressure issue on a stock fuel delivery system. Main relays normally work or they don't once the car is running. When you see intermittent failures it's starting the car, once the relay latches it tends to stay that way until you shut the key off.

John Chagolla

I also have installed a JDM motor on a 1999 Honda Civic. I also see 1337 code. I have followed the instructions in the bypass trick and did not work for me. Still have the code. Seems in following instructions my wire from blue plug off ECU is not the same location as instructed. I connected blue/red with yellow. I also connected white/red with black. So what's wrong? Still have error.

I like the other guy installed sensor from old motor to JDM motor. So why the error. I have taken apart the old oil pump and just see gears. So how can oil pump trigger sensor? Also I inspected old crank pulley and Don't how that triggered sensor in old motor. If I install old crank pulley to JDM motor will that work and trigger sensor? What if I install oil pump gear from old pump to JDM oil pump will that make the sensor work?

I just want 1337 to away. Won't pass emissions with check engine light. Please help.

JRCivic1

The CKF sensor is mounted externally on the outside of the oil pump housing. The magnetic pick up detects pulses created by the crank timing gear... not the crank pulley or the actual oil pump drive gears. The USDM OBD-2 style crank timing gear has multiple blade like tabs attached to the rear edge of the gear itself, and the outer edge of each one passes within a few thousandths of the magnetic pick up face of the sensor.

So to be clear, the proper fix is to install the following items to properly fix the CEL: A USDM '96-00 oil pump (complete assembly), crank timing gear, CKF magnetic sensor pick up, outer lower timing belt plastic cover and of course plug in the sensor. You will have to change the 3 wire oval shaped plug to a two wire plug and of course repair your wiring inside the car at the ECU.

John Chagolla

Thank for an awesome and compressive explanation. I do have follow up questions. Can I simply install crank tming gear from my old motor and install unto JDM motor,? Can the old oil pump from old motor be installed unto the JDM motor,? Seems other people have issues with install of usdm oil pump in that doesn't fit unto JDM motor.

Any idea why trick on ecu did not work?

John Chagolla

To answer my own question is no the Crank timing gear can not be used from old motor to JDM motor. Why? It's because the Crank shaft from old motor is 0.9 inches where as the JDM motor has a shaft of 1.1 inches. Also to note the JDM I have is a ZC model. To get parts like harmonic balance will be a pain to find let alone to find a crank timing gear. I am hoping I can find dam gear so the Crank sensor will work. My question now is why would ZC model motor have a thicker shaft? After exhausting searching I was able to crank oil seal.

JRCivic1

I thought we were talking DOHC engines here... now you have stated that you installed a ZC. So, are you saying that the crankshaft snout is LONGER or WIDER in diameter ??? How about the shoulder area where the front main seal makes contact with the crank shaft ??? Are they similar or does one stick out farther than the other one ???

John Chagolla

The old motor and JDM are both SOHC. Perhaps would of had been better to state motor model or brief description. The Crank shaft that is the area I had describe is the area that crank gear attaches to and the same area oil pump is attached. The shaft is the same length and only difference is the shaft diameter is different. ZC model is thicker and thus ultimately has has larger oil crank seal and requires a larger innner diameter crank gear.

JRCivic1

Gotcha... I wonder if the DOHC '96+ Integra or '99-00 Civic Si crank gear would fit ???

John Chagolla

Question. If the crank sensor is not connected will that not allow the car to start? Just a recap the jdm motor I bought did not have crank sensor nor crank timing gear it just had crank gear. Also if I cut wires that is ecu trick that disables crank sensor does the sensor have to be connected?