mithious

93 Del Sol, D16Z6.

I'm hoping someone can point out what I'm not understanding here.

As my TPS (throttle position sensor) has never been calibrated, (still had the shear bolts) I figured I'd calibrate it and see if I had any improvement in throttle response. I followed a DIY thread here that was pretty good, except it doesn't quite seem to make sense... This is what I did:

1. used a hacksaw to cut grooves in the bolts that hold in the TPS and unscrewed them.
2. took apart and cleaned the throttle body. The TPS itself looked perfect inside.
3. calibrate the TPS (at WOT loosen the TPS bolts and twist the TPS until it reads 4.5 volts, then tighten down the bolts. then use the throttle stop screw to adjust the closed throttle position to 0.48 volts)

Pretty straightforward. No problem up to there. Except, adjusting the closed throttle then left the throttle plate just slightly open. I was then idling about 1200 rpm. I tightened the idle screw all the way in to account for this increased airflow (as the tutorial also suggested), but I was still at about 900 rpm, instead of the 750 my canadian D16Z6 should be at.

This just doesn't make sense to me. Shouldn't there be a better way to calibrate this where the throttle plate is fully closed when the TPS is set to .48?

So I adjusted it again, but started with the CT position instead of WOT. I set the throttle stop to where the plate seems closed, then I twisted the TPS until it was at .48 volts and tightened it down again. Now it seemed to idle perfectly, I set it to 750, and I still have adjustment either way with the idle screw.

The only problem is, WOT is now beyond 4.5... At 4.7 or so. I have no idea what the ECU does with a voltage beyond 4.5. I expect that I do not hit WOT often, but I would still like this reading to be correct. I would have learned a little more had I checked the voltages it was set at before I took it all apart... Anyway.

Car is responding really well, but I'd still like to figure out how to set this properly.

Anybody know how to solve this? Is this calibration in the service manual? I do not yet have a copy of that.

Former User

This^ is the proper method. Then reset the ECU.

But you don't adjust anything until you test the output voltage first to see if an adjust is even needed.

It's fine.

mithious

Talk about a quick response! Thank you.

Definitely should have just checked it first...

I guess that's all I needed to know! Thanks.