Hey guys I am pretty much a beginner and am having trouble finding the source of my code 4 CKP sensor.

Here is the rundown, sorry it is so long but I am trying to be thorough.

88 Civic wagon DX converted to mpfi with a subharness I bought locally to run D16Y8 with a chipped P28 running Neptune. The car was running great for about 2 months before this started a few days ago.

The original Y8 distributor was repinned and for the original 5 pin OBD-0 large distributor harness plug and cut and soldered for the 2 pin plug. Blu/yel and Blu/grn which I think are the CKP wires are just soldered right now I don't have a 2 wire plug to make it oem looking yet.

I borrowed an OBD-1 distributor from a friend and rewired it with the distributor plugs I was running and still got the code 4. I disconnected the battery for an extended period of time to make sure the code wasn't stored.

I would really appreciate any advice at this point, my limited knowledge is tapped out.

If I wasn't clear on anything please let me know

 

ok, i had code 4, cps, and all wiring was correct. i had no clue what was wrong. finally i depinned my c1, c2, b10, and b12 wires from the ecu plugs, and checked them individually to make sure they squeezed onto the ecu pin good (made sure they were making contact) 3 of my 4 depinned wires were super loose on the ecu and made no contact! i crimped the female ends with a pliers to make sure they grabbed the ecu pins well, and problem solved! try it

 

Thanks man I will look at this in the morning when theres some light. I am going crazy because I am out of ideas.

 

Well it turns out the problem is with the DPFI to MPFI jumper harness I bought. Both wires for the CKP were loose in the jumper plug.

I tried to fix them but it got worse. The pins and plugs are aftermarket and I am not sure how to depin them yet, let alone buy new pins. The wire just fell right out of the pins which are still in the plug.

On one hand I am very glad it wasn't something I was doing wrong re wiring the distributor but I am frustrated I didn't know to look at the distributor first.