TPS Adjustment

[greekmaster]

I adjusted my TPS by taking it off, cracking open the case by drilling out the rivets, and so on. That TPS turned out to be flawed, so I got a new TPS. Does anyone out there know how I can adjust it properly without cracking open the case? I need to know when the idle contact opens and when the WOT contact closes. How can I do this?

Thanks

Nathan

[sblake01]

Remove the connector from the Throttle Valve Switch and connnect a voltmeter. You'll need an old TVS connector, strip the three wires on it and connect your voltmeter there. Using the center wire as common, the front wire is the full throttle contact and the rear wire is the idle contact. The idle contact should be closed (continuous) when the throttle valve is at idle and open in any other position. The full throttle contact only opens when the throttle valve is at full throttle which is 35 degrees or more than the idle position and it's open whenever the throttle valve in any other position. When you've achieved these settings, tighten the screws, remove the tester and plug the cars connector back on. I highlited the name because it's not really a Trottle position switch or sensor as in the more modern EFI systems but, for some reason, people call them that.

[76Datsun280z]

In the EFI bible, they just call it a "throttle switch".

[greekmaster]

Thanks for the directions. Basically I'm checking for continuity with my ohm meter.

Nathan

[sblake01]

In the EFI bible, they just call it a "throttle switch".

Yeah, the FSM's call it either one. Throttle switch, or throttle valve switch depending on the year. The difference is that it just has the two sets of contacts and only works in those two positions while a true throttle position sensor operates throughout the entire range of throttle movement. To answer Nathan's question, yes. With a good throttle switch you'll have continuity at the idle contacts at your idle speed and as soon as you move the throttle to anything above idle it should go away. When the idle contacts are set properly, the full throttle contacts will also be right since there is no internal adjustement but I always check them too to make sure.

[Rockr69]

The TPS idle contacts are supposed to break contact at 1400 rpm. With the cover off, have a helper hold running engine at 1400 rpm and adjust switch contacts on idle side to just open. Lock down the screws, replace cover. Procedure as outlined in FSM.

[greekmaster]

That's exactly what I did with the previous TPS, but I would really rather not uncover my new one. The previous TPS I adjusted to open at 1400, but again, that required me to drill out the rivets and mess the whole cover up. I'd rather not, so if you have an other trick way of doing it I'm all ears.

Nathan

[COZY Z COLE]

http://www.atlanticz.ca/zclub/techtips/tps/index.html

LARRY

[sblake01]

With the method I described, you don't have to open it. That's just a way of showing what it does a the different positions. A continuity check will do the same thing with the cover on. As far as opening one up to clean the contacts, that's a different story but you don't have to open them to adjust them.

[Rockr69]

I agree with Stephen. Going by your avatar I assume your working on a zx so I dug this out for you

. I would also assume the procedure could be used on a 280z by throttling to 1400 and then doing the adjustment. Hope this helps.GL.

[sblake01]

Where does the 1400 RPM setting come from? I've never seen that anywhere except on Atlantic Z. I set mine to open at anything above idle which would be somewhere around 900 RPM as stated in your attachment. The 280Z FSM doesn't give a speed. It says approximately 4 degrees rotation from idle speed.

[Rockr69]

Again Stephen your wealth of Z knowledge continues to astound me. You are once again correct. The 1400 does come from AlanticZ and thanks to your astute observation of my error I will readjust my switch correctly. I apologize to all for posting incorrect info. My FSM does say contacts closed in idle position, open at any other position except WOT, then closed on the other contacts to compensate for WOT fuel enrichment.