I have an 82 crossfire that needed valve cover replacement. In the process of putting the covers back on, I had to remove the throttle position sensor. Now that it is back on, I get idle up and down like a vacum problem, but I get a code 22 saying TPS. How do I adjust and to what voltage??

 

You have 3 wires on your TPS. They are signal, supply, and ground. You should be able to tell which is which because the ground will have no voltage, and will have resistance to ground when a volt meter is set on ohms. The supply wire will have constant voltage when the throttle is opened and closed with the key on, the signal wire will have varying voltage from 1 to 5 volts. Check your signal wire with the key on, then slowly and smoothly open and close the throttle and you should see the voltage smoothly change from 1 to 5 volts. If you have something other than 1 when it is closed you probably need to adjust it to one. I have the exact procedure for this somewhere, (although for an E4ME, not a crossfire) but will need to look a little deeper for it. If nobody with an 82' GM service manual reply's I'll look it up for you and post it here. Later.
EDIT: I'm pretty sure what you want is .62 volts between pins B and C of the TPS with the key on, A/C off, and throttle closed all the way. You will need to make a jumper to get access to the wires to measure that while it's connected, or you can pierce the insulation on the wires, i just don't like to do that if I don't have to.

-Justin


[Modified by Dalannex, 9:56 AM 11/23/2003]

 

Either go to say Zip corvette or even Ebay and get a 82 GM shop manual. They're reprinted and available everywhere and look up the procedure for this. This book will also help you if/when you have to deal with anything else.

or

Go to the Crossfire Injection Vault website which is in part run by CF member Twin Turbo and sign up to be a member and you will then get a password which will give you access to the many write-ups for taking care of the CFI motor. These are information with pictures and tips/shortcuts. Really invaluable info.

Best Regards, Brent...

 

turn ign on, engine off. Don't touch the gas, pull the throttle rod to see if the plates return to their idle pos. properly. Then measure the boltage over the signal wire and ground. Set TPS to 0,525 +/- 0,025V. You can move the TPS by loosening the 2 allen head screws. You don't want to loosen them much, just so slightly that the TPS is hard to move (it takes very delicate adjustment), set it as close as possilbe and check the reading after you tighten the bolts..

If your TPS is out of adjustment so much that it causes the check engine light to light up and you don't have a DIMM then you can start the car, carefully move the TPS untill the light is off. This won't be a correct setting but you can drive it somewhere to have it properly done.


[Modified by Twin_Turbo, 6:32 AM 11/24/2003]

 

I needed help setting the TPS sensor on my 82 crossfire, and that's exactly what I got! Thanks to the three people who gave me the answers I needed. I have been out of town but will be under the hood tonight and driving tomorrow!

 

My 82 Idles fast during start up about 1100 rpm, after about 1 minute the idle increases to about 1400 rpm (I think this happens when the smog pump is running or when there is air coming from the accordion hose on the pump, when the pump stops doing whatever it does it idles back) then as it warms up it will idle back to 1100 rpm (warmed up in park), when in drive the idle is around 800 rpm. I have followed the procedures in this thread and I have my meter set on Volts DC between pins B and C on the TPS and I don't get the 5v that the thread states I should have no matter what I do. When the car is running I can adjust the TPS and the engine will rev up and down but I cant see the voltage that I'm supposed to have. Another possible issue I have is when sitting in park, engine warm, and I punch the accelerator, rpms go up normally but come back down very slowly, not immediately like I think it should? Any help would be appreciated and I have tried to get to the http://www.crossfire.homeip.net/ page but all I get is " this page can not be displayed".
Thanks much for any suggestions.

 

Get one of these and make your life simpler:

 

Agreed on the adapter. Major parts catalogs carry them. Say they are for an 84, but work on an 82 also. Have been using mine for years. 84-82 - same engine at least regarding anything to do with a tps.

 

There is a free program you can download called WinALDL (google it) Get that and make/order a cable and use that to set your TPS, its much easier.

 

KEY ON...ENGINE OFF. Have your voltmeter set on the 2 volt scale for DC volts. Sometimes when I have my voltmeter set on the higher scale...it looses its ability to show a precise reading. .525 volts is where I set them at...even though I know there is a +/- variable to compensate for it being off just a little bit

Depending on how smooth your idle is...and how long it takes to go into "closed-loop" and if eh idle "hunts"...you can have some vacuum leaks or issues with the balancing of the throttle bodies and if the Idle Air Control valves (IAC) are doing their job. If the idle is smooth.....then without the car being in front of me with my scanner attached to it so I can see what is going on when it is warming up...it is hard to actually say.

DUB

 

did you make or buy your cable.i need to get one

 

I bought mine years ago when I had a different Vette. I put a TPI on a 77 in 2005, got the cable then. This site http://www.aldlcable.com/ sells cables.

 

I need a 12 pin usb end .60 bucks .I think I wil ebay first .thanks

 

Thanks DUB.
After about 3 hrs of reading the forums, I came across one that said to adjust the idle stop screw (on the front TB) to just touch the idle arm then back it off 1/4 turn. I was able to bring the idle down quite a bit just backing that screw out a little. The RPM's are lower now but the idle is a bit rough. I located a few emission vacuum hoses along the drivers side front fender that are cracked pretty good. Ill replace them asap and see how it idles then.
Thanks!

 

You have other problems to work out if the idle is that high. Chances are you have a massive vacuum leak. If your TBI's and throttle linkage have never been played with I wouldn't touch them until you figure out why its idling that high. My guess is you need to replace the lid gasket and TBI gaskets or something else is leaking. TPS out of range doesn't give you a high idle.

If you go from 1100 to 1400 its probably because the diverter valve for the pollution control pump is leaking when it opens. Disconnect the feed to it from the front TBI and plug it. See if your idle comes down. You can also eliminate the leak to those hoses you mention by unplugging them and plugging at the supply just ahead of the distributor on the driver side. You could have multiple vacuum leaks.

As for adjusting the TPS. I used two paperclips straightened. Two clips to attach the meter probes to the paper clips. Works just fine. Or just tape the probe ends to the paperclips.

Jim

 

Please explain what is needed for an 82. Make order a cable? and how does this help to set the TPS?

 

TravisF,
I have fixed so many 82 and 84 Corvettes with the Cross-fire engines that I just get cross-eyed thinking about them.

Doing what you did in the quoted post is really not correct. backing off the idle screw 1/4 turn is a guessing game at best. The balancing of your throttle bodies precisely requires a manometer and special block off plugs for the IAC's. I have these tools and go to them when ALL other considerations have been inspected and repaired. I do not use the "piece of paper" method...only because when I use my manometer..it allows me to really fine tune the throttle bodies...even though if I did the paper trick first to see how well it really works... only to see how far off they truly are in adjustment when the manometer is used.

Exhaust leaks at the cylinder heads need to be fixed if you have ANY.

Really check for vacuum leaks. I have run into so many that need the upper gasket of the top plate of the intake replaced...along with the gaskets below the throttle bodies also.

It does not seem to be your problem...but I have encountered so many that have worn out or very "touchy" throttle body shafts...which create havoc when attempting to adjust and balance the throttle bodies.

I also check to make sure that ignition is the best it can be also.

If you plan on balancing the throttle bodies...and you do not have the factory service manual...I would get one.

I hope that these vacuum hoses are the culprit. If not...let "us" know.

DUB

 

It is so you can read the info from the ALDL port ...which will give you your TPS reading ad adjust it that way. You download a program so you can read the data when the engine is running i guess. I do not need this cable and program due to i have a scanner instead.

If it were me and I was planning on keeping the car for a long time...get one of the connectors that were previously posted with a photo and use your voltmeter with it. I have one...but often times I use my scanner to read the TPS so I can adjust it that way.

DUB

 

Yeah, the price has doubled since I bought mine. Mine isn't USB though...

 

Where can you buy one of those TPS jumper/test cable hanesses like pictured above. I search the usual places and can up empty....may have to resort to the safety pins and then TRV the holes when finished.