PhobicBanana

I have a '97 honda prelude sh and recently replaced the clutch and flywheel. After putting the tranny back in a checking every connection multiple times it fired up and drives fine. But after getting to running temp and trying to roll into v-tec it rev limits at 5000rpm. I pulled codes and pulled a code 54 which is the crank fluctuation sensor. The weird part is if i drive in a higher gear at like 4000-5000rpm and drop it a gear it will go above 5000 no problems. Anyone have any ideas or suggestions? Any info would be greatly appreciated. As well could the MAP sensor be part of that problem? it has a misfire on cylinder 2 and would the o2 sensors be part of the reason for that misfire? it has an erotic idle, and runs extremely rich. i have replaced the plugs, wires, cap and rotor on the distributor, i have also cleaned all four injectors, as well as the egr valve, and the fuel rail. i aslo put the money into it for a new fuel pump, and i had hollowed the cat. I'm going to replace the o2 sensors anyways because supposedly they make or break a honda. is that true? could it possibly be the knock sensor, from a loose flywheel? like i said any information would be extremely helpful in what to do next, or what to check. the ecu is fine. and it is the p5m. and the correct ecu i believe.

holmesnmanny

Odds are it is in fact the crank fluctuation sensor. I would clean off the sensor and the balance gear. They could just be dirty and not allowing a proper reading. If not, then just replace the crank sensor assembly.

98_Prelude_615

I agree with holmesnmanny. I had a similar issue and then it just died on me and would not run. After a lot of money on things that did not fix it i took it too my friend that works for a Honda Dealership as a mechanic and he told me it was the crank shaft positioning sensor. Its a paint to get to cause it sits behind the timing belt. So if you do change it you might as well change your timing belt and water pump ect while your there anyway.

http://www.ebay.com/itm/97-98-99-00-01-Honda-Prelude-OEM-crankshaft-crank-cam-shaft-sensors-H22-ckf-/331161448602?pt=Motors_Car_Truck_Parts_Accessories&hash=item4d1ac2b09a&vxp=mtr

98_Prelude_615

I agree with holmesnmanny. I had a similar issue and then it just died on me and would not run. After a lot of money on things that did not fix it i took it too my friend that works for a Honda Dealership as a mechanic and he told me it was the crank shaft positioning sensor. Its a paint to get to cause it sits behind the timing belt. So if you do change it you might as well change your timing belt and water pump ect while your there anyway.

http://www.ebay.com/itm/97-98-99-00-01-Honda-Prelude-OEM-crankshaft-crank-cam-shaft-sensors-H22-ckf-/331161448602?pt=Motors_Car_Truck_Parts_Accessories&hash=item4d1ac2b09a&vxp=mtr

PhobicBanana

Ok thank you i will tear into it today or tomarrow. Another question... It ran just fine before i had to do the clutch, then it sat for about 2 weeks. Would it just sitting like that cause the sensors to go bad? I figure since they were fine when i dug into the car, they should be fine still. Thats why im torn between it being a bad sensor or I just missed plugging a sensor in somewhere. One more thing, near my air filter there is another connector (orange) I dont remember unplugging this from anything in the process of dropping the tranny. Could this be the potential problem? Or is there typically an extra connector for some addon from factory? I work primarily with Euro cars so still learning daily about this honda. Thanks again!

holmesnmanny

It depends if the code was there before you tore into it or not. I suppose you could have wiggled loose a wire from the distributor connectors provided u unplugged them.

PhobicBanana

There was no check engine light before i changed the clutch. I did unplug the distributor leads. What should i look for on the distributor side? I checked the Crank Sensor seems to be functioning properly. After unplugging it and checking the wires for a short or a break in the wire i plugged it back in and the check engine light is now gone. But it still wont rev past 5000. If you could point me in the direction as to what to look for on the distributor end i would be greatly appreciative! As well as how many ohms should i be getting off of the oil pressure switch? im getting anywhere from 5.0 to 5.6ish ohms. Is that normal or is that a low amount of power?

holmesnmanny

odds are its not the distributor connectors .. ur gonna need to pull the timing belts and take a look at the crank sensor assembly and balance shaft/timing gears for dirt, grime, corrosion, breakage.

PhobicBanana

but what kind of ohms should i get from the oil pressure switch? i found one a guy is willing to let me try

98_Prelude_615

When my check engine light came on after reving it and it went into limp mode and would not let me rev past 3 grand... i just reset the battery and it cleared the engine code so i wouldnt trust just that the engine light aint on anymore.. With that being said i had my friend hook up a computer (a 5k price one, not one of those 50 dollar ones from auto zone) and test the wattage or ohms of the crank sensor and it was not reading good so he said it was bad, changed out the crank pos sensor and it fixed it.. I am sorry though i cannot remember the ohms on it. Google or call a honda dealership maybe they will tell you on the phone