I was testing my TPS and at idle I was registering numbers of about 984 ohms. Before I adjusted it, I figured I'd test it WOT too and so I found a brick to slam my gas down. When I came back to test it, I couldn't get anything to come up. I took the brick off the gas and still I got nothing. I never could get anythign to come up no matter what I did (shut the car off and back on, shut the multimeter off and back on, etc.). Anyways, I was wondering if anyone knows why it stop sending me info? Also, if at idle it was at 984, I know thats not the perfect 1000 but is it far enough off to cause me problems? Thanks!!!

P.S. I was going to try to get it to the perfect 1000 but I couldn't get it to tell me anything anymore!!!

 

Did you perhaps blow the meter by checking resistance on the TPS while it was powered? Check the fuse in the meter...Or, better yet, set the meter to voltage and look for approx. 1 volt at warm idle- IIRC, the green wire to ground...It's much easier than trying to get a steady reading using resistances that jump all over the place...

 

God I hope I didn't blow the meter, it is my dad's and I didn't ask to use it, lol. How could I possibly blow the meter? I thought the car is supposed to be on (not actually running but key in the on position) while your checking the TPS.

I don't know anything about electricity, I just did what the FSM said. What kind of household item can I test to see if the meter is workign properly?

 

If you're checking resistance (ohms), the power should be off (key off)...If power is on, you WILL blow the meter...

If you're checking voltage, the power should be on, of course...

IMO, it is much easier to set the TPS using voltage, and the key on (doesn't have to be running, but DOES have to be a hot engine)...

Try reading the "Basic electrical troubleshooting for the RX7" thread- do a search, it's around somewhere in cyberspace...

 

Ok, updated. I friend of mine had another multimeter I could use so I tried it again and these are the numbers I came up with... At idle, it was about 1,300 which is over the 1000 factory setting. However, at WOT it was only like 1,800 ohms of resistance. This is significantly less than the factory setting of 5,000 plus or minus 1,000 (basically, the lowest it should be is 4,000). Can anyone tell me what this means? If I adjust it one way, it will fix either at idle or at WOT but it will mess up the other one won't it? I don't know if this matters or not but I don't really have any problems at WOT, only at idle. Thanks!!!!

 

Plug the connector back together, start the car & let it warm up until the fast idle cam "kicks off", then set the meter to voltage, and check the green/red wire (pos lead) to ground (neg lead). Keep her running at idle, and tweak on the adjust screw until the voltage is 1 volt, +- .1 volt. Now, turn the car off, then turn the key back on, and move the throttle linkage while watching the meter. Should start out at your 1 volt, then rise smoothly with throttle movement (go slow) up to about 3.8 volts. If this is all good, your TPS is good. If not, it's not. Simple, eh?

 

Wayne88NA uses the hot engine voltage method.
It's less convenient, but works well because it allows for harness & connector resistance.

 

Simple indeed, except for one problem. I do all that while the car is running and I don't think I can get to that plug w/o taking the intercooler off. Can my car run w/o the intercooler? (probably a really stuipd question but its coming from a really stuipd person, so it all makes sense). Thanks as always!

 

nice questions jester I'm about to do the same things on an 88tII so your stupid questions are my stupid questions as well however I do know that with the ic off your car will not run do to a huge vac leak however maybe if you could connect a piece of wire from each lead to the parts that you need to check with the ic off then put the ic back on it may work.

 

I was thinking that would create a massive vac leak but I wasn't too sure,

 

Can one check the voltage at the ECU?

 

Yes, in fact that's how I check mine- at the ECU, for a couple of reasons, the foremost being that at that point, this IS the voltage that the ECU is seeing, and checking it at the ECU tests the entire circuit- TPS, wiring, and power...In fact, I like driving around with the meter hooked up to the TPS pin at the ECU- it checks the entire range of throttle movements throughout any "transient" event you put on the engine...

This is the solution for you turbo guys, also...

 

hmmm ... I thought that's what everybody was doing ... I've tapped pretty much all wires at the ECU plug to have something to look at when I am driving ... everyday I monitor something different with my trusty voltmeter.

just kidding. Listen to WAYNE88 .. truer words have not been spoken.

hugues-

 

so what is the presedure? Witch wires where etc... Thanks.

 

I need to do a detailed writeup for you guys one of these days, but I'm too busy right now...

Suffice to say, you need the FSM, fuel section for the pinouts & normal voltages you should see, and you need to pull the carpet back & get to the ECU. Then all you need is your trusty meter, and maybe a couple of jumper wires with clips to make life easier...

Once you get the hang of it, you'll find you can troubleshoot the entire car from this one spot...

 

so what is the presedure? Witch wires where etc... Thanks.

 

It's all in the FSM ...
For each pin, you have the voltage you should see.

hugues-

 

Can't agree more.

 

sorry for the double post didn't mean that at all anyways yes a write up would be great seeing as how me and wiring in cars goes over my head like taxes!