Thread: Key Out - Engine Still Runs

Background on my car: 2000 Sentra SE that I just performed a B14 conversion on (ECU and IM).

The car starts and runs, but the problem I am running into is when I turn the key to the off position. After doing so, the engine revs up, going from about 1,500 RPM to 2,000 RPM and continues to run for about five seconds.

I don't have an OBDII scanner at the moment, so I can't pull the codes from the ECU to see if any of the codes could be causing the problem, and the car is not drivable right now so I can't drive it to Autozone.

Does anyone have any ideas on what could cause this or what I should check?

what is ur idle set at 1500rpm thats kinda high. and we need more detail, did u do a swap of some sort.

when i did mine i lost my high idle...? but i never swapted over my intake manifold, i am running a ve one, with no idle air controlle
did u wire in an iac or no

I haven't set my idle yet. I have only run the car for about 30 seconds to a minute at a time since the cooling system is not in yet. I didn't think 1500 RPM was too high for a cold start on a engine that hasn't run fro a year.

The B14 IAC is wired in, but I have a feeling part of the wiring may be wrong since another B15 owner (JP) needed to hook another of the wires to a 12V switched source. Could that cause this issue?

im pretty sure its the wiring. I had the same problem with my 02 p11 when I first wired it, the car would run after the key was out of the ignition for a little while before it eventually turned off. When i took it to the shop, they redid it for me and now the problem went away. Granted i never even soldered it, so it could have been a bad connection.

They didn't happen to say what it was that needed rewiring?

it was the ecu plug wiring, i also have a electronic boost controller and emanage wired to the b14 conversion, so they just redid that part for me. They never really said anything specific to me, just said its fixed.

I believe this had something to do with the MAF wiring. I am using a Cobra MAF, and I had one of the wires wrong (since the B15 has 4 wires going to the MAF and the Cobra only uses 3 according to the JWT instructions).

After fixing the wiring the engine fires right up (before it would take 2-3 tries for it to fire). The car won't idle, but I believe that is a separate issue.

Doesn't the Cobra MAF have 4 wires? Two are ground IIRC.

That's correct, but the B15 harness does not have two ground wires, so you combine the ground wires from the Cobra MAF (B & C) into one.

There are actually two "Power" wires to the MAF on a B15. One called "sensors power supply" only provides 5V. The other is a switches 12V source. The other two wires on the B15 are the signal wire and ground.

Too late to just get a B14 engine harness to match the ECU you have?