Throttle position sensor.

While blowing a few cob webs out of the Baja up the beach on the weekend, engine light started to come on and then go out for a while. Seems to stay on longer now several days latter. Engine- 92 ej22 error code 31. Do I just replace the throttle sensor and thats that or is there a voltage problem that sets it off? Will try a 2nd hand one I have here or shall I just get a newy straight up? Best mod to Baja= EJ22.

Is it still driving and running normally?

When theres a fault with the TPS or wiring those gen1 ECUs will default bump the idle up to 1500rpm.

I broke one of the wires off mine many years back, it was still drivable but it had a nice flatspot on take off.

Joel the engine seems fine with no change in idle. Most off the time the light is off! I will just watch it for a while.

Bone wrote:Joel the engine seems fine with no change in idle. Most off the time the light is off! I will just watch it for a while.

most if not all TPS use 5v, Ground and a signal wire.

Check the 5v reference is indeed 5v and check the ground although depending of ECU maker it could be a virtual ground.

No easy way to check the signal line other than from the plug back to the ECU using a multi meter.

And of course I would try replacing the sensor first as that will be 95% change of the problem. Sound like its wearing out, I had one go once and no CEL came on, it was bad but still within rage that the ECU just compensated for it. it caused the idle to surge coming up to stops.

Joel wrote:Is it still driving and running normally?

When theres a fault with the TPS or wiring those gen1 ECUs will default bump the idle up to 1500rpm.

I broke one of the wires off mine many years back, it was still drivable but it had a nice flatspot on take off.

yep a flat spot cos there of lost AE function cos there is no reliable way of the ECU determining engine load.

Bone wrote:Joel the engine seems fine with no change in idle. Most off the time the light is off! I will just watch it for a while.

I'd say its a wiring issue rather than a sensor fault then.
Just one of the wire periodically breaking the circuit

Joel wrote:

Bone wrote:Joel the engine seems fine with no change in idle. Most off the time the light is off! I will just watch it for a while.

I'd say its a wiring issue rather than a sensor fault then.
Just one of the wire periodically breaking the circuit

Will swap with the other first and take it from there.

vlad01 wrote:

Bone wrote:Joel the engine seems fine with no change in idle. Most off the time the light is off! I will just watch it for a while.

it caused the idle to surge coming up to stops.

I have actually noticed a small surge when coming to stops. This has happened from day 1 of engine conversion. "Thought it was normal". swap to other TPS tomorrow arvo and see!

Swapped TPS and bingo, Fixed!

glad we could help.