Jump to content
CaddyInfo Cadillac Forum

94 Seville Throttle/ Idle HIGH


tm8272

Recommended Posts

Hello everyone, I drove my 1994 Cadillac Seville for first time in a week to Home and Garden show at fairgounds yesterday. When I started car to leave as I was driving out of parking lot the motor idle raced up to over 2 RPM as i was waiting on traffic and my turn to go. It shocked me and the security guards directing traffic out looked at me. I immediatley put car in park and turned off the engine. Had to have my foot on the brake to keep car from taking off fast. I restarted the car and it seemed ok until I made a pit stop and when I restarted it again the motor raced like I had my foot on the accelerator to 3 RPM! I turned off the engine again, thinking I might have a run away Toyota! Very scarey! I restarted car and was only 3 miles from home so I put it in reversed and it jerked because of engine speed. When I put car in neutral as i went to stop signs the engine reved even higher!! Neutral made it worse!! I got the car home safely but was thinking good thing it was dry and nice weather and not snow or ice!!

I turned car off and it smelled hot. I pulled codes today and no current codes. I started car and same thing the engine went to 2 RPM without me touching the gas peddle. Made sure nothing touching gas paddle or causing it to stick. I did a snapshot of condition and turned car off. I went into OBD and no codes but pulled snapshot data and got: P013 which is Rear Heated Oxygen Sensor Not Ready. I read in manual that possible causes are: Throttle between 5.4 and 25 degrees or Throttle switch open. Does anyone think it could be the Throttle position sensor? If so can I pick it up and replace myself?? Thanks for any info! This engine has been replaced with a new Jasper Reman and only has about 600 miles on new engine. Not sure if this would be covered by the Jasper warranty or not. They are not in on weekends and I have other vehicles to drive so leaving this parked til issue is resolved. Thanks again for any thoughts! Hope everyone is having a good weekend. I have not searched posts on this issue yet on here but will do so next.

Link to comment
Share on other sites


When you turn the key off, all the codes go to History. To see the codes that reflect what is happening, you have to check the codes while the engine is still running. Since that isn't an option, simply write down *all* the codes and post them here.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

Link to comment
Share on other sites

my oldsmobile cutlass 3100 did the same exact thing a few years ago, it ended up being the coolant temp sensor (ecm not cluster) went bad and it was showing temperature being -40*f and was making it run at higher idle. I didnt drive it far at all

GM FAN FOREVER

Nice, clean, luxury= fine automobile

Link to comment
Share on other sites

Being a 94 Northstar, your engine has an Idle Speed Control (ISC) motor. If the contacts in it become dirty or don't meet up right, it can cause a severe high idle. I had that problem a year ago. It's a fairly pricey part to replace, but can usually be fixed with a good cleaning. I would give it a shot. The cleaning procedure is pretty quick and painless.

big4870885.jpg

Link to comment
Share on other sites

Being a 94 Northstar, your engine has an Idle Speed Control (ISC) motor. If the contacts in it become dirty or don't meet up right, it can cause a severe high idle. I had that problem a year ago. It's a fairly pricey part to replace, but can usually be fixed with a good cleaning. I would give it a shot. The cleaning procedure is pretty quick and painless.

Thanks for all the suggestions everyone! I did spray some WD 40 on cables and tried to clean as much as I could. That really helped a lot! The ide is now down to 1 RPM on tach when it is started. Still not as low as it should be. Is there any special cleaner I should buy for throttle plate and sensors?? I checked my codes again and still have NO codes showing up so that leads me to believe it is a cleaning issue. I have not found a vacuum leak yet. Carla you mentioned you had a similar issue, did you use any special cleaner to resolve your issue? Thanks again to everyone that commented! I did call Jasper engine to see if any of this was covered under warranty and they told me my old sensors were swaped by installer and that was my expense if it was sensors. If it was a vacuum leak then that would be covered by installer and warranty. I will continue the cleaner with a special cleaner if I can buy one to do a good job and then go from there.

Link to comment
Share on other sites

It is not advisable to lube the throttle and/or cruise cables. Lube will attract dirt and cause binding. Check the Idle Speed Control motor - tons of information on that in the archives - do a search on ISC.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

Link to comment
Share on other sites

Is there any special cleaner I should buy for throttle plate and sensors??

Buy a can of TB cleaner from your local parts store. They say not to use carb cleaner, but I still have some Gumout carb cleaner left and have had no ill effects from using it. DO NOT use it on any sensors though. You shouldn't need to clean any sensors that I can think of, but if you do, use an electrical parts cleaner or Brakleen. Those leave no residue.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...