Stuck in limp mode

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Mint green s13
Posts: 1
Joined: Mon Apr 15, 2019 4:04 pm
Car: 1993 Nissan 240sx s13 hatch

Stuck in limp mode

Postby Mint green s13 » Mon Apr 15, 2019 6:31 pm

I built this ka24de about a year ago. Put it in, ran fine and it sat while I did the body, suspension etc. and I don’t remember messing with anything on the engine in this time. now it’s stuck in limp mode and won’t go over 3500 rpms. It starts no problem as long as the mafs unplugged but wants to sputter out without throttle, especially with the maf plugged in. Also revs itself up to about 3500 rpms and drops back down repeatedly without giving it any throttle. The eccs relay also buzzes loudly when the key is in the off position, and it’s pitch changes with the maf plugged in (not sure if this is at all related to the issue). I read codes and got one for a coolant temperature sensor and a knock sensor. I’ve already tried a new ecu, distributer, eccs relay, tested continuity for all wires to the ecu, and pulled the intake to be sure there were no vacuum leaks and clean out a valve that was stuck open. Any information would be helpful as I’ve been stuck on this issue for weeks. Thanks in advance 👍

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Posts: 204
Joined: Wed Apr 10, 2019 2:50 pm
Car: 1995 240SX SE - KA24DE-T
2014 Camaro SS 1LE

Re: Stuck in limp mode

Postby NukeKS14 » Mon Apr 15, 2019 8:24 pm

Did you change the coolant temp sensor? I saw you did a continuity check on the harness but nothing about the actual sensor.

Did you do anything about the knock sensor code? Replace it or verify the mini harness isnt bad?

Check your engine grounds and especially the large ground from intake manifold to body near the fuse box.

Are you able to get it warmed up and check timing? You mentioned replacing the distributor. Could be a tooth off.

I didnt see it mentioned either but check voltage on your tps at closed and wot. I use a couple of bent paperclips to backprobe the harness.

Just out of curiosity, you didn't replace the distributor with a spectra unit did you?

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