Rough Idle 72 Cutlass -  

Go Back > Vehicle Lineup > Cutlass, 442, and Hurst/Olds > Cutlass

LinkBack Thread Tools Search this Thread
Old May 23rd, 2008, 04:08 AM   #1
Registered User
Join Date: May 2008
Posts: 45
Rough Idle 72 Cutlass

If its the first time starting my car during the day I need to hold the gas down a little and kinda rev it so it doesnt turn off. If i let go of the gas it will just turn off. After i do this for a couple minutes and turn it off or drive it. Its fine for the rest of the day. Whats the problem?
UCF72Cutlass is offline   Reply With Quote
Old May 23rd, 2008, 04:33 AM   #2
Registered User
Rallye469's Avatar
Join Date: Feb 2008
Posts: 371
Does your car have a choke?
How much do you have to rev it to keep it running?
'70 Rallye 350 BEST: 6.87@100.00
'65 F-85
Rallye469 is online now   Reply With Quote
Old May 23rd, 2008, 05:12 AM   #3
Registered User
Join Date: May 2008
Posts: 45
Not to sure about the choke. Its a 74 350 4bbl quadrajet.

Dont have a tach so not sure on the rpms but just a slight steady pressure on the gas pedal keeps it alive. Let it go and it dies.
UCF72Cutlass is offline   Reply With Quote
Old May 23rd, 2008, 05:33 AM   #4
Old(s) Fart
joe_padavano's Avatar
Join Date: Mar 2007
Location: Northern VA
Posts: 19,131
Sounds like either the choke coil is bad or needs to be adjusted. There should be a round housing on the passenger side of the carb with a black plastic cover (about 2" in diameter). Three screws hold the cover to the housing. Loosen the screws and you can rotate the plastic cover. Move it one notch towards rich and see if that helps. Failing that, there is also a fast idle adjusting screw on the carb. This is NOT the regular idle speed screw. If you're going to make these adjustments, you need to get a Chassis Service Manual or Rochester carb book to have all the diagrams in front of you.
Joe Padavano

62 F-85 Deluxe wagon (the NV desert car)
62 F-85 Deluxe wagon (the San Jose car)
64 Vista Cruiser
64 Jetstar 88 Conv
66 442 L-69 Conv
68 W-30
69 H/O
69 442
70 W-30
72 442
84 Custom Cruiser
86 Caprice wagon (w/307 Olds)
joe_padavano is offline   Reply With Quote
Old May 23rd, 2008, 06:06 AM   #5
Jim's rare 80
Join Date: Feb 2007
Location: Hamilton, Ont. Canada
Posts: 210

Simple test. With the motor cold, pull the breather off and see if the choke is open, or closed. It should be open. Pull the throttle linkage back, and the choke should close. "spring tension". get someone to start the car, and watch the butterfly valve. If it fires, then stalls, and the valve doesn't open, it's your choke pull-off, or the vacumn line to it..
Let us know what you find.

Last edited by Jim's rare 80; May 23rd, 2008 at 06:09 AM.
Jim's rare 80 is offline   Reply With Quote
Old May 24th, 2008, 02:21 PM   #6
Registered User
Join Date: May 2008
Posts: 45
So i have no other way to describe this but the car had a zip tie around something that controls the choke. i cut the zip tie and now the car starts right up and idles fine. what was the reason for that?
UCF72Cutlass is offline   Reply With Quote
Old May 29th, 2008, 03:22 PM   #7
Registered User
Join Date: May 2008
Posts: 45
too bad of description huh. soorrrry
UCF72Cutlass is offline   Reply With Quote
Old May 31st, 2008, 07:09 PM   #8
Registered User
Chumley's Avatar
Join Date: Dec 2005
Posts: 451
I have found that some previous owners of our classics never took auto shop in high school or anywhere else. I have found some very Mickey Mouse setups on the '72 Culass I bought last year. The upper radiator hose is tied to the support with a shoestring. ( I guess that was their budget at the time) I'm still finding little surprises as I go through this car. Joe was right on with the fast idle screw, although apparently that was not the problem with your car. I just recently put on a new Q-jet and had a rough idle as well. A little tweaking of the fast idle screw solved it. The repair manuals are worth the investment. Get an original GM manual if possible.
Chumley is offline   Reply With Quote

Similar Threads
Thread Thread Starter Forum Replies Last Post
72 cutlass rough idle ELECMAN General Discussion 1 June 19th, 2015 06:58 PM
Stumped on hot rough idle. 68ragtop General Discussion 14 August 24th, 2008 09:44 AM
Rough idle after 20 seconds or so skubydobdo General Discussion 20 August 18th, 2008 03:32 PM
rough idle projectheaven Small Blocks 2 July 8th, 2008 12:16 AM
rough idle novice57 Small Blocks 4 June 3rd, 2008 04:35 AM

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not 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 Off
Pingbacks are Off
Refbacks are Off

All times are GMT -7. The time now is 04:38 PM.

All content Copyright 2008 by Internet Brands, Inc.