Rough idle when warm - HELP! - Impala Tech
Performance Our High Performance Area

LinkBack Thread Tools
post #1 of 4 (permalink) Old 09-11-2019, 06:38 PM Thread Starter
Join Date: Jul 2016
Location: Brooklyn, NY
Posts: 53
Rough idle when warm - HELP!

I'm going a little nuts here.
So recently I began experiencing a really rough idle after driving around for a while.
When I first start up the car (which it does straight away) it runs fine but after driving around for a while I notice when I stop at traffic lights the engine will almost stall, before revving up again, over and over.
Last year I put a Flame-Thrower Cast Stock Look Distributor with Ignitor III along with a Pertronix Flame Thrower III Ignition coil and had great results until just recently.
So, thinking it might be a faulty distributor I swapped it out with the old points distributor and coil.
At first everything seemed good until again, the car is driven a while.
What on earth is going on??? Help please!
The only other thing I have changed is I swapped out my rusty old Magna Flow mufflers for a set of Walker Quiet Flow's; surely that wouldn't cause an issue like this?
I have also put new spark plugs in and fuel filter in a bid to solve this issue.

kiwidave is offline  
Sponsored Links
post #2 of 4 (permalink) Old 09-11-2019, 06:39 PM Thread Starter
Join Date: Jul 2016
Location: Brooklyn, NY
Posts: 53
FYI, I have a small block 350 in my 64.
kiwidave is offline  
post #3 of 4 (permalink) Old 09-11-2019, 07:24 PM
Join Date: Jul 2009
Location: Canada
Posts: 1,487
Set timing correctly. Set idle speed correctly. Set gap correctly. Set mixture correctly. Adjust choke correctly (hot and cold). Look for vacuum leaks. Can't make any guesses until the basics are all taken care of.

Two doors, four doors, wagons, and ragtops.
jayoldschool is offline  
post #4 of 4 (permalink) Old 09-12-2019, 12:16 AM
Join Date: Jan 2006
Posts: 12,932
Could be any of the above but it sounds like a fuel problem since it is running fine off idle. Do not confuse the main jets and the main circuit with the idle circuit. That is were your issue lays if it is a fuel air issue.

Could even be a gas line routed too close to the exhaust that is boiling gas at idle but allowing enough liquid through at part throttle to run fine.

Wish I could drop by to diagnose: but I'm stuck in a sauna called Central Florida right now.

Big Dave
Big Dave is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Impala 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:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

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