High Rpms on Start!!! - Team Camaro Tech
Troubleshooting Diagnosing problems done here.

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 18 (permalink) Old Dec 7th, 00, 03:45 AM Thread Starter
 
Join Date: Dec 2000
Posts: 7
Cool

When I start my car the rpms go way to high. It only does it when it is cold outside. After I get almost to work which is about 15-20 minutes I can depress the brake really hard and it goes down. I carried it to the GM dealership and of course they did not find anything wrong. But they still charged me. I need help!!!! Please E-mail or respond
Thanks
Beaver is offline  
Sponsored Links
Advertisement
 
post #2 of 18 (permalink) Old Dec 7th, 00, 03:55 AM
Senior Tech
 
Join Date: Mar 2000
Posts: 715
Question

Is it fuel inj or carburated? Need more info.Carbs have a fast idle screw that is on the passenger side that can be adjusted. This is the choke idle speed screw.

------------------
68 RS, Ash Gold,pwr windows,Hounds tooth
CA420 is offline  
post #3 of 18 (permalink) Old Dec 7th, 00, 05:21 AM Thread Starter
 
Join Date: Dec 2000
Posts: 7
Post

It is fuel injected.
Beaver is offline  
 
post #4 of 18 (permalink) Old Dec 7th, 00, 07:55 AM
 
Join Date: Dec 2000
Posts: 4
Post

I think most of all fuel injected cars have a idle air control. If the car has some mileage, they get like stuck either open or closed. Maybe take a look at that and spray some carb cleaner to clean it up or maybe replace it.
Z-head is offline  
post #5 of 18 (permalink) Old Dec 8th, 00, 12:19 AM
Senior Tech
Bruce
 
Join Date: Jan 2000
Location: PA
Posts: 922
Post

my 90 rs had the same problem, but only when cold. i had problems with the wiring harness that went to the tps switch (3 prong plug).
i went to gm, bought a kit, and replaced it and that solved my problem.
here the wires got corroded and broke loose to the pins inside the plug and would cause a bad connection.
cost me 23.00 bucks and haven't had the problem since.
bruce
bruce69camaro is offline  
post #6 of 18 (permalink) Old Dec 8th, 00, 03:30 AM Thread Starter
 
Join Date: Dec 2000
Posts: 7
Post

What would I ask for at GM? A wiring harness for the tps switch?
Beaver is offline  
post #7 of 18 (permalink) Old Dec 8th, 00, 03:31 AM Thread Starter
 
Join Date: Dec 2000
Posts: 7
Post

I called my local GM dealership and they told me I would have to buy the whole engine wiring harness. They said I would cost me about $500.00. That is a little too much for me.
Beaver is offline  
post #8 of 18 (permalink) Old Dec 8th, 00, 03:56 AM Thread Starter
 
Join Date: Dec 2000
Posts: 7
Post

Its getting colder and I need to fix this kind of fast. Any help is greatly appreciated. Bruce69camaro get back with me and let me know what I can try. Thanks
Beaver is offline  
post #9 of 18 (permalink) Old Dec 8th, 00, 10:02 AM
Tech Team
 
Join Date: Oct 2000
Location: Stockton, Ca
Posts: 74
Post

I used to have an 83 mustang and i put a brand new double pump carb, and when it got cold out here in california, it would do the same thing, start it up in the morning, and it would jump to around 2000 rpm, then settle down, maybe the problem isnt in your fuel injection??? just a thought
bigtedards is offline  
post #10 of 18 (permalink) Old Dec 9th, 00, 09:33 AM
Team Member
John
 
JohnZ's Avatar
 
Join Date: Sep 2000
Location: Washington, Michigan USA
Posts: 7,728
Post

Only two things affect idle rpm - the TPS switch tells the computer whether or not your foot is on the accelerator past idle position (and how far), and the Idle Air Control motor opens, modulates, and closes an air passage into the manifold during idle when the throttle plate is closed to manage idle under varying load conditions. One of these two devices (or their electrical connections) is causing your problem, assuming your engine computer is working and its electrical connections are good.

------------------
JohnZ
'69 Z28 Fathom Green
JohnZ is offline  
post #11 of 18 (permalink) Old Dec 9th, 00, 03:20 PM
Senior Tech
 
Join Date: Nov 1998
Location: ohio
Posts: 252
Post

First thing would be to take a real close look for a vacuum leak. Then suspect a worn throttle body. You would need to scan the computer and check the IAC counts. Normal might be about 17, with a leak somewhere you might be seeing much less or even zero. Could possibly have an out of spec temp sensor telling the computer it is 30 below zero too. A dirty connection could cause this. Again a scanner will pinpoint this real quick. Check for vacuum leaks first. Check throttle body bolts.
tom3 is offline  
post #12 of 18 (permalink) Old Dec 9th, 00, 05:56 PM Thread Starter
 
Join Date: Dec 2000
Posts: 7
Post

I tried taking it to the dealership and they checked it and said they could not find anything wrong. What do I need to do???
Beaver is offline  
post #13 of 18 (permalink) Old Dec 10th, 00, 05:17 PM
 
Join Date: Oct 2000
Posts: 75
Post

Beaver, if it is throttle body injected the base gaskets do give a problem. You could do a key on engine off check and listen to see if the IAC motor is at least working, you should hear it clicking trying close. Then again its hard to believe a dealer didn't try any of this.
MY396 is offline  
post #14 of 18 (permalink) Old Dec 11th, 00, 12:43 AM
Senior Tech
Bruce
 
Join Date: Jan 2000
Location: PA
Posts: 922
Post

sorry i took so long to reply back, but i went in and asked for a repair kit, for this plug, and they gave what what i asked for. i beleive pep boys might also have a repair kit for this plug. if i remember correctly, they call it a gm weathertite plug kit, for this tps switch. but ever since i replaced mine, my car has worked fine. in the mornings, when it was cold, i'd go out and start it and the rpm's would go high, until i would try and drive it, then after the car got a little warm, it work then work. but after i would let it sit, the same thing. i try and drive it and it would spit and putt around and bearly move. then after it got a little warm, it would be ok.
the harness kit had the plug end with three wires about 8 to 10 inches long and came with crimpable wire ends. it has a gm part number, but i threw out the bag it came in.
bruce
bruce69camaro is offline  
post #15 of 18 (permalink) Old Dec 12th, 00, 01:38 PM
Senior Tech
 
Join Date: Feb 2000
Location: Waldorf,Md,USA
Posts: 176
Post

Beaver, if it is throttle body fuel injected, try this, with the engine running, spray some carb cleaner around the base of the throttle body and if the idle comes back to normal, the problem is the base gasket under the throttle body. I had this happen to a friends truck and by replacing the gasket, all is well. Hope this helps.

------------------
Leo Paugh
MCC #017
www.clark.net/pub/chevelle/mcc.htm
There are no strangers here, only friends you haven't met.
chev64 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome