Motor sputters out under heavy acceleration at higher RPMs - Team Camaro Tech
Troubleshooting Diagnosing problems done here.

LinkBack Thread Tools Display Modes
post #1 of 7 (permalink) Old Apr 15th, 02, 05:28 AM Thread Starter
Senior Tech
Join Date: Jul 1999
Location: denver, co USA
Posts: 407
I have a 1967 Camaro all restored back to stock condition. The motor has 900 mile since a complete rebuild. The carb is the original Q-Jet that is rebuilt. When I drive the car, it starts great, idles great, runs under normal conditions great. But when it is time to have fun and put the acclerator down, the engine will sputter and lose all power, almost like there is a rev limiter or something. Yesterday, at about 3500 rpm in third with the accelerator floored, it lost all power, but the motor did not die, it sounded like it was just idling. It would not respond to the accelerator pedal at all. I turned on a side street and a few seconds of just idling and I was on my way again. Again, this occurs ONLY under full acceleration and ONLY above 3500 RPM or so.
I thought that the car may be running out of gas with the secondaries open, so I installed a larger needle and seat and hi-flow fuel filter but that did not help. Would you guess it is still in the fuel system somewhere? The coil giving out at higher rpm? The coil arcing maybe? The distributor doing something weird (I have not gone through the distributor yet)? Or something else? If there are any steps or tests you recommend, I would really appreciate it. Thanks in advance.
denverRS/SS is offline  
Sponsored Links
post #2 of 7 (permalink) Old Apr 15th, 02, 07:18 AM
Senior Tech
Join Date: Aug 2000
Location: seattle, wa
Posts: 172
hows the fuel pressure?
5 1/2 to 6 psi is normal for stock pump.

Stock 67 327 RS
goatjj is offline  
post #3 of 7 (permalink) Old Apr 15th, 02, 09:00 AM Thread Starter
Senior Tech
Join Date: Jul 1999
Location: denver, co USA
Posts: 407
I have not tested the fuel pressure with a gauge, but can tell you it seems to come out very strong. I will add the fuel pump to the list haha. Thanks.
denverRS/SS is offline  
post #4 of 7 (permalink) Old Apr 15th, 02, 09:47 AM
Super Moderator
Bess-68's rule
Everett#2390's Avatar
Join Date: Sep 2000
Location: Va Beach VA
Posts: 31,650
The next time this happens, do this.

When engine acts up, turn off IGN switch and keep pedal to floor. Coast to a safe spot on the side of the road. Raise hood, remove air cleaner, and insert a pipe cleaner into bowl vent and retract cleaner.

Check the end of pipe cleaner for gas moisture. If there is none, fuel delivery problem. If there is fuel, then ignition problem.

Fuel pump should provide min. of 1 quart of fuel in 15 seconds, idling.

Should also check fuel tank and fuel line for resrictions, hose conditions, etc.

Everett 68/350/PG/11.90/115mph
Everett#2390 is offline  
post #5 of 7 (permalink) Old Apr 19th, 02, 05:43 PM
Senior Tech
Join Date: Mar 2002
Location: Austin, TX, USA
Posts: 5,277
If you're running breaker points, add a condensor to the list of oddities. Usually, a bad condensor will behave like a rev limiter regardless of load, but a cheap test non the less.

Make sure your secondaries aren't comming on too soon. Are they mechanical or vacuum operated?

dnult is offline  
post #6 of 7 (permalink) Old Apr 20th, 02, 01:31 PM
Team Member
JohnZ's Avatar
Join Date: Sep 2000
Location: Washington, Michigan USA
Posts: 7,728
The fuel pump should deliver a pint in 30-45 seconds.

'69 Z28 Fathom Green
JohnZ is offline  
post #7 of 7 (permalink) Old Apr 21st, 02, 05:01 PM
Senior Tech
Join Date: Aug 2001
Location: Newmarket, ON, CANADA
Posts: 513
denverRS/SS, I am currently having the very same issue. Same exact symptoms, @ full throttle. I changed my fuel pump to a Holley Perf. mechanical and the same issue occurs, I changed fuel filter the same. My fuel pressure is @ 6lbs when the engine is cool and 3lbs when hot at idle and that is a concern I've had, but I think this is due to vapour lock.

What I have found that helped, is advancing the timing. The moment I did that, the bog at high RPMs went away and performance increased.

[This message has been edited by mikestr (edited 04-21-2002).]
mikestr is offline  
Sponsored Links

Quick Reply

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


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:


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