box_goblin
NAXJA Forum User
- Location
- Seattle, WA
Intermittent throttle issue that has gotten progressively less intermittent.
I wanted to check a few things with some folks with more experience before part swapping, here goes:
90 XJ, 4.0L, AX-15
Throttle (more often than not) spikes to 2-3K right after startup. It does not normally come down on it's own, but will more often than not go back to normal (~750) if I drive and force the engine to lug down using the brake while in 1st.
I know that the TPS is the questionable part here, so I did test mine per the chart in the FSM.
Input Voltage: 5.02 V
Output with Throttle off was showing 0.65V
I adjusted the TPS to set output V up to 0.85 per the manual's specs and fired up the engine.
Engine went right up to 2500 RPM
Unplugging the TPS revs the engine back down to a normal idle (why does it do that, anyhow?). Plugging it back in immediately after the disconnect and the idle remains normal; it does not spike back up. The temporary interuption to the TPS seems to reset it some how?
So, the question really is, does this indicate that the TPS is at fault here? Or could it be something else? Thanks in advance!
I wanted to check a few things with some folks with more experience before part swapping, here goes:
90 XJ, 4.0L, AX-15
Throttle (more often than not) spikes to 2-3K right after startup. It does not normally come down on it's own, but will more often than not go back to normal (~750) if I drive and force the engine to lug down using the brake while in 1st.
I know that the TPS is the questionable part here, so I did test mine per the chart in the FSM.
Input Voltage: 5.02 V
Output with Throttle off was showing 0.65V
I adjusted the TPS to set output V up to 0.85 per the manual's specs and fired up the engine.
Engine went right up to 2500 RPM
Unplugging the TPS revs the engine back down to a normal idle (why does it do that, anyhow?). Plugging it back in immediately after the disconnect and the idle remains normal; it does not spike back up. The temporary interuption to the TPS seems to reset it some how?
So, the question really is, does this indicate that the TPS is at fault here? Or could it be something else? Thanks in advance!