Ron U.S.M.C.

I was told to move this to the TBI section in order to get help.
I have done the research and know quite a bit about TPSs.
Even the non adjustable one that I have. I know that it can be reset and have just done that. I tested the non adjustable again and still come up with .85v. I'm shooting for .45v.
I have performed a little experiment with my TPS by adjusting the throttle stop screw down a 1/4 turn to see if there was a change in the reading of the TPS. It dropped to .81. At that rate I would have to turn the stop screw beyond its capability. I believe this indicates a bad TPS but I would like some confirmation please.

Tuned Performance

iTrader: (92)

If you can't get the tps down to .54 or so slightly elongate the holes on the tps. have you checked rockauto.coms pricing or using some of the part numbers found on rock auto and search ebay for a screaming deal.

Ron U.S.M.C.

My TPS has no meat to file and comes with these specifications.
http://www.rockauto.com/catalog/more...469&cc=1035694
So you mention .54 is that the the highest the TPS should be reading ?
The book says .45
If I do replace it with a new one is there a special procedure or do I just plug it in ?

Tuned Performance

iTrader: (92)

Plug and play .I cant recall the spec I thought it was .5 plus or minus .05 . I have used a chain saw round file to slightly elongate the holes but if your min idle is set that's quite aways off. Too much resistance.
http://www.ebay.com/itm/Adjustable-TPS-86-90-GM-TBI-Silverado-Sierra-Suburban-Camaro-Firebird-Caprice-/190836150597?pt=Motors_Car_Truck_Parts_Accessories&hash=item2c6eb89145&vxp=mtr

Tuned Performance

iTrader: (92)

I might have a new one I will take a look and let you know.

Tuned Performance

iTrader: (92)

Pic1

Tuned Performance

iTrader: (92)

Pic2


You would need to compare the direction the lever goes. I know this is the opposite of tpi but I just can't recall if its tbi or maybe for a caddy. If you want to try it just for the shipping and it works we can work out a very fair deal.

Ron U.S.M.C.

As long as mine looks like this and the ECM is looking for its preset values I’m going to replace it with the Standard brand direct OE TPS.http://www.rockauto.com/getimage/get...69-0&width=450 Thanks for suggesting Rock Auto
What I do need to know is if my throttle adjustment screw is going to need to be adjusted to bring the idle to exactly 700 rpm (what the book calls for)
That's with the car at operating temp. Is that in Park or drive?
I don't really want to install a new TPS with the RPM even a little off.
That would screw it up right?

And thank you Tuned Performance for your offer.

My timing is set at the stock "0" degrees or at least as close as I could get it. Another reason to check the idle speed.

Tuned Performance

iTrader: (92)

You are correct Ron, if the idle adjustment moves the tps voltage moves along with it.
Do the minimum idle speed in park. This would be ex actually what you would get from a dealer.
http://www.oewarehouse.com/searchitem.epc
I have ordered a lot of parts from them. the only bad if they are out of stock on a part expect about a weeks delay before shipping.

Ron U.S.M.C.

I cant find it there and theres no one to call.
I looked even under my VIN #.
and under 1989, Chevy Camaro,5.0 TBI, Auto.
With no results.
Would you walk me through it and grab me a part # ?

Tuned Performance

iTrader: (92)

That's a odd one , email and cc these email addresses.
sales@oewarehouse.com, jimlove311@gmail.com, jlovesr@optonline.net

His name is Jim love
The acdelco 213-907 ?
Is that what it physically looks like ?
http://parts-catalog.acdelco.com/cat...tock_check.php

Ron U.S.M.C.

Yes

Tuned Performance

iTrader: (92)

Yup na, looks like the other style works it just changes the position of the weather back plug straight up.

Ron U.S.M.C.

Sorry about all the questions but that's how I learn sometimes. Not every question is put on paper so to speak.
If the opportunity comes across to set the value coming from the TPS to the ECM exactly on the money than I will. I don't know exactly what that value is but the stock non adjustable TPS does.

Wednesday I’m going down to have the RPM adjusted exactly to 700rpm.Then I’m going to test the TPS one more time. If it’s still off (and I hope it is because that means I’ve found a very elusive gremlin) I’m going to order the one from "OE Warehouse"

Thank you Tuned Performance for the work you put into this and for sticking by me in a time of need. Hopefully I will be able to return the favor someday.
Ron

Tuned Performance

iTrader: (92)

NP Ron, if you have a tach in the car here's some reading material
http://www.autozone.com/autozone/rep...00c1528005c67c

Ron U.S.M.C.

My tach is wasted. How does this relate to the 700 rpm the book is asking for with the TPS adjustment ? =

From Auto Zone = "For 1989 vehicles, set the idle screw to obtain 400-450 rpm for the 4.3L (VIN Z) engine or to 450-500 rpm for the 5.0L (VIN E) and 5.7L (VIN 7) engines."
(5.0L (VIN E) is my car.)

I just read this again = https://www.thirdgen.org/tpimod2 =
Idle Air Control

Tools needed:
1.Torx bit # T-20
2.Paper Clip
3.Small Punch



Take the paper clip and open it up and form it into a big "U" shape. Insert the clip ends into the ALDL in the 'A' and 'B' pins.

Turn on the ignition, but don't start the engine. Wait 30 seconds. Now, go remove the connector from the IAC.

Start engine. You are now going to adjust "minimum air". There is a Torx screw on the side of the throttle body. This is what needs to be turned to adjust minimum air, or more commonly known as "idle speed". It comes from the factory with a protective metal cap over it. If the cap is still there, use a small punch to knock it out. Set the idle speed to 450 rpm, rotating the Torx screw clockwise to raise rpm, and counter-clockwise to lower rpm. Once the idle rpm is set, turn off the engine.

Re-connect the connector onto the IAC. Start engine. Idle speed is now once again governed by the ECM, but your idle should be smooth and steady, approximately 600 rpm in Drive (for unmodified cars).

Tuned Performance

iTrader: (92)

450-500 is the minimum idle speed. this sets the iac count to the correct position 15-30 steps. you could avoid all the aldl and iac in plugging steps with a scanner. The ecm is in control of the target idle speed. The target idle speed is based off coolant temperature.
This is why you have a high idle at 160 steps and at around 150f the rpm drops to the 700 range.

Tuned Performance

iTrader: (92)

You can't just start adjusting the throttle stop screw.

Lurbie

iTrader: (3)

Maybe you've got a wiring problem. Go back to what you know about how a TPS actually works. 5v, Ground, and Signal circuit. As the throttle is moved, the signal circuit moves along a resistive winding from being closer to the ground circuit (throttle closed/low voltage) to being closer to the 5v circuit (throttle open/high voltage). This is how the voltage changes as the throttle position changes. So if your TPS signal circuit is closer to the Ground circuit (providing the low voltage reading) and you can't physically adjust it lower, then perhaps you have resistance in the Ground circuit to the TPS itself, causing the higher voltage to be read on the signal circuit (because there is not enough ground continuity to bring it down any lower).

Ron U.S.M.C.

I first grounded the Meters black lead to the battery and touched the Gray wires jumper = 5v
Then I did the same thing to the blue wire = .85
Then I touched the pos. lead from the meter to the blue wire jumper and the neg. from the meter to the ground wire and have a reading of = .85
I switched around the meters wires and touched the ground wire with neg. lead and pos. to the battery and had 12v.

I used a short process to set the IACV found in my manual.

Ron U.S.M.C.

What can I do to fix this problem without a scan tool, I tested the TPS and it came up defective. I want to "through" new part in there with the idle set at 700 rpm.
You’re telling me I can’t?
Are you saying I need to use the IAC adjustment to set the RPM first then install the new TPS without adjusting the rpms ?

Tuned Performance

iTrader: (92)

With the iac set bye the rpm adjustment the tps will be in. Range unless there is a vacuum leak. So you said the throttle blades were completely closed and the feed back wire to the ecm (the blue wire) would only go down to .85 vdc ?

Ron U.S.M.C.

No I only turned the screw 1/4 turn because I did not want to mess up my starting position.
All of this would not be such a major pain if I had a timing gun with the RPM setting.

Tuned Performance

iTrader: (92)

Tach repair is $35 as a service in the classifieds, might be the cheapest option.
https://www.thirdgen.org/forums/engi...-sale-all.html

Ron U.S.M.C.

Could be but a timing gun with the rpm setting is really the only tool I don't have. Through out the years if I needed it I bought so I believed I had every thing I would need except that. The only reason I have not bought one is price. So If I put off ordering the TPS, I have found one on line for $ 65.00 with the RPM setting.
The car has to be fixed !

Should I bottom out the throttle plates/butterflies and take a new reading ?
Probably a waste of time if the RPM are off.

Ron U.S.M.C.

Quote = "You can't just start adjusting the throttle stop screw."
https://www.thirdgen.org/tpimod2

OK,
I finally see that the only adjustment to RPM is done when the IACV is installed and set. There is no mention of any RPM setting with the TPS.
Soooo, I must set the IACV first.
Confirmation please .

Side Note = If I only "realized" this in the beginning .

Thanks again

Tuned Performance

iTrader: (92)

just curious what lead you to the tps ? was is a check engine light code 21, or is it running rich at idle ? You might want to hold off on adjusting the throttle stop screw until you get a tach. I'm sure you already know but just throwing it out there the timing is set with the est dis connected. In the order of adjustment for a adjustable tps. I Always set the timing first, then the minimum idle speed followed bye tps if adjustable.

Tuned Performance

iTrader: (92)

The rpm with the iac commanded in and unplugged is 450 if it can be obtained if not 500 rpm.

Ron U.S.M.C.

Yes it does smell like its running rich but what led me to the TPS is my installation of a new IACV. I had read that the TPS should be adjusted if the IACV was replaced but I never did it. Now I’m realizing there are two problems. One is the improper setting of the IACV and on top of that the TPS has never been adjusted. (Timing is properly set to stock "0" *)
As long as this is correct I will be buy a timing gun with the rpm readout and commence on setting the IACV properly. After that I will test the TPS again and if it’s off than I will replace it. Hopefully with those two items being extremely important to the car, fix/adjusting/replacing will solve my stalling and starting issues. If not at least I have eliminated them as suspects.
I would like to use these directions but he does not say when to remove the paperclip ground or if the car needs to be at operating temp.

https://www.thirdgen.org/tpimod2

Ron U.S.M.C.

Just a little follow up.
I started out slow but have learned allot.
With the help of Tuned Performance and others through PMs
I finally came around.

Soooo...
I ordered a digital timing light that also showed RPM.
I checked to make sure the timing was at "0*"
Then preformed the procedure of setting both the "IACV" and "minimum idle speed" that was provided by Tuned Performance.
Tested the TPS after that and it was within acceptable range.

It’s only been two days so far but not one stall. And the car has been starting fine. I think the car may finally be grateful enough to run like I know it can.

Thanks again guys !