I have the intake manifold assembly all cleaned up at this point and mostly assembled. It's sitting on my desk in the house, so I have unfettered access to all parts of it. Anyway, I thought I'd check the adjustments of the throttle pulley and throttle position switch while I have a chance. So far I got the idle linkage rod set up correctly, per the faq (have the throttle gap set at about 0.180 - 0.200 mm when the throttle pulley is 2.5mm from stop). But now I have a couple questions:

- should you do all the adjustments in order that they're listed in the faq? I can't do 2 and 3 til I get it back on the car again.

- I understand item 4, and my tps appears to be out of whack since I get the click on closing the throttle with the 0.45 mm feeler gauge between the idle screw and throttle stop. I don't quite understand the adjustment procedure though, and before loosening the tps I want to make sure I know what I'm doing.

It says to First turn the TPS clockwise (away from the electrical connector) until it stops. I don't get what it means by away from the electrical connector, and so can't figure out if they mean to turn it clockwise relative to the front or rear of the throttle (when it's in the car).

Then you turn it the other way til it clicks, then keep turning til it stops - this part makes no sense to me - why turn it past the click until it stops?

Thanks for any clarification. If it would help I can stick up a few pictures.

FAQ reference link

For the most part, with LH 2.4 and Regina, idle is all computer controlled and cannot be changed. The more you leave the throttle body open to raise idle speed, the computer will simply close the idle valve to keep idle at the same speed. In short, the throttle body and TPS never really need any adjustment on these cars, unless the throttle plate is binding. Just inspect them when you clean them. :-)

Also, with computer control/compensation, you can be kind of sloppy with setting things up... so don't sweat it. :-)

As for setting things up: simply set the throttle stop "set screw" so that the throttle plate is just *barely* open and not binding... then lock it in place.

Now think of what the TPS "does": when your foot is off the gas, the idle position must be engaged so that the idle air motor/valve takes over the idle process. When you mash on the gas pedal, the WOT position is closed, that'll tell the ECU to richen the mixture for full throttle.

With the throttle plate adjusted properly, and in the "resting" (closed) position, simply turn the TPS until the switch just "clicks" into the idle position. Tighten it up. Now open and close the throttle by hand a few times. If the switch repeatedly clicks, you're done.

Now with the linkage, here's the trick: it needs to just be adjusted so that it doesn't lift the throttle plate out of the idle position, and consequently keep the TPS from engaging its idle position. Once that's set, it's done!

Be careful not to mix up the harness connectors for the TPS and the IAC motor.

Let us know how you fare!
-Ryan
--

Athens, Ohio
1987 245 DL 314k, Dog-mobile
1990 245 DL 134k M47, E-codes, GT Sway Bars
1991 745 GL 300k, Regina, 23/21mm Turbo Sway Bars

It just has to be set up to click with the slightest (1 deg) movement of the throttle plate. I believe it will click again at wide open.

Thanks guys. Well I looked at it again just now and found that I get no click at WOT. Yesssss now I get to adjust it...

set the throttle stop "set screw" so that the throttle plate is just *barely* open and not binding... then lock it in place. - Well with the way it is right now (I haven't fiddled with this screw), when the throttle is closed against the screw I can just see the faintest chink of light past the throttle blade. I bet you could just barely fit a hair through it if you tried. I'm no good with piddly things, so I"ll just assume it's ok, and move on to the TPS adjustment.

For one thing, the throttle I have here doesn't go the full 180° when at WOT. It's like 160-170 I would guess. Is that normal? The throttle pulley has another stop that it hits when you go that far.

Also, no matter how I adjust the tps, there's no click at WOT. Are you sure it's supposed to?

I also unclipped the ball-socket link to be able to manually open the throttle blade even more, and no matter how far you go, there's no WOT click.

Not sure about the WOT thing. Others have said it's supposed to click at WOT but since I'm not a "WOT" sort of driver I've never given it much thought or tried to test it on my '88. I wouldn't sweat it much if I were you. Just get it running well at idle and make sure it turns off the IAC when you lift the throttle slightly. You can always take the switch out and turn it manually to see if you get two clicks.