IAC/TPS adjustment

Thanks to all. I've just read all of your suggestions and they have enlightened me.

Kev, thanks for the photos. They were the biggest help. I didn't realize (or read clearly enough) that you back probe from the connector side until you repeated it in your post. I also didn't realize you could slide the TPS harness off the clip. Big help there. BTW, I think my biggest problem is my meter. It just wanders all over. I picked the very same one up that you have at Harbor Freight for $4.

Keith, I'm not quite sure what you mean by "reference voltage". Could you elaborate. It looks like Kev had the pins and probes in the right places.

Pete, as I said above, my problem is probably my meter as well as not getting good connections. Having a better understanding of the Tech Article was also a big help. (As a side note, could you explain how to upload photos. I tried last night and couldn't seem to get them on the site.)

Thanks, Keith and Trashline for the probe connection idea. Keith, I saw what you did in the photo under your hood. Very clean.

The only thing I'm still not sure of is the difficult starting. This may work it's way out once I get everything adjusted. I did take the IAC off and detached it from the solenoid to clean it out. I used the original gasket because it was still in one piece. Could the gasket and the O-ring be at fault for the poor starting?

Thanks again. I'll let you all know how it goes.

MJ

Originally posted by Michael Jordan:
BTW, I think my biggest problem is my meter. It just wanders all over. I picked the very same one up that you have at Harbor Freight for $4.

MJ

Yep, got mine at Harbor Freight for $4 too in Little Rock AR. I hope you get all your problems figured out.

Just a side note on the back probing, etc... I tried back probing the connector as well on mine and couldn't get it to read correctly so I used scotchlock connectors and attached speaker wire to the green and black wires with the scotch locks and put my meter probes to the speaker wire to set mine. Is this not a valid way to do the same thing?

Michael
Picture filenames must be all one word, no spaces in the name. They should be a little under 500 KB. They must be .jpg or .gif.format I was able to get a .txt file to upload once.

After you have selected you picture and uploaded it be sure to click on the link in the "Upload Form box" to "automatically post it into your post" That puts a link to the picture(s) into your post

Thanks, Pete. I'll try posting a photo of my car soon.

Back to my question regarding reference voltage. Keith mentioned this in his response to Kev's photo of the probes contacting the pins. I get the very same 5.7 volt reading when I contact mine. When I try to adjust the TPS nothing happens on the meter. Is this an indication of a bad TPS? I still can't be sure if I'm getting proper contact. I may try a more positive way by splicing in some leads for the probes. ArkieRebel, you mentioned scotchlock connectors. What are they and where can I get them?

I'm still wondering about the rough starting and re-using the IAC gasketfrom my previous post. Anyone have any thoughts on these points? Also, can anyone tell me how the TPS detaches from the clip?

Thanks.

MJ

Reference voltage is like the power input voltage for some sensors - TPS, VAM for example. The other two wires are signal (voltage) back to the EEC to indicated the sensors state. The black wire is the signal return which is like ground.

If you getting 5+ volts, you are probing the wrong wires. TPS voltage should vary from under 1.0volt to about 4.6 volts max at WOT position.

On the TPS harness connector look for a raised plastic wing - think sharks fin. The TPS connector will have a plastic tab that hold it in place. Gently raise the plastic tab enough to allow the fin to slide underneath it as you pull the harness connector straight off. See pic. I think the whole conncto assy detached from the clip in the same way. Lift the metal tang to so the connector can slide out of the clip

http://natomessageboard.com/uploads/0000...S_IAC2.JPG

Pete, your absolutely right on the voltage issue. I was most likely sticking the pins on the wrong contacts inside the connector. I assumed since I was pushing the pins next to the green and black wires that I would be hitting their respective contacts, but I went back and this time stuck the pins through the insulation so I knew I was contacting the right wires, set my base idle at about 750, adjusted the TPS to .94V, checked the throttle a few times with engine off and key on, got up to 4.1V (+/-) a couple of times, started the car up without touching the gas pedal and it settled right in between 950 and 1000 rpm.

Sometime when the engine cools down I'll fiddle around with the TPS clip to see how it slides off.

Thanks again to all of you.

MJ

So, now that I've got it all adjusted what can I do to keep it from revving to 2000 on start-ups. It eventually idles down or I can kick it down by blipping the pedal but those fast cranks take their toll on the bearings. Also, the idle still wants to wander a little, Is there some other reason for this?

MJ

Not sure why it's going to 2K on startup. How much is it wandering? Whenyou had the meter hooked up did you move the linkage slowly through the entire range looking for flat spots or dropouts. Sometimes these are not picked up. If you are getting a lot of idle wander and you know the IAC is clean and good, it may be the TPS anyhow. I've run into that once or twice. It test good but idle still wandered.

It doesn't wander too much. As I said in last night's post it settled in between 950 and 1000 rpm but this morning after driving on the interstate for about 15 miles it was idling at about 1400 then settled down to about 1100.

If everything is set right what should the start-up idle go to? Like I said it settles down or I can kick it down but that first surge you can really hear the bearings knock. If it doesn't surge on start-up , which it sometimes will do, it's nice and quiet.

MJ