Motor help please
New User
Joined: Feb 2000
Posts: 2
Likes: 0
Motor help please
70 F-100 with 360. Holley 4 barrel. tomatic. Rookie owner.
Runs very rough when cold but runs great after that. After warmup sometimes at a stop the motor sort of "bucks". By that I mean the RPMs go up and down slightly and most times will stall at a long light. It "bucks" in neutral also.
Q1: Is the cold start most likely a choke problem?
Q2: Is the motor "bucking" maybe a fuel pump problem?
I had someone tell me that it could be related to motor mounts but......?
Thanks.
Runs very rough when cold but runs great after that. After warmup sometimes at a stop the motor sort of "bucks". By that I mean the RPMs go up and down slightly and most times will stall at a long light. It "bucks" in neutral also.
Q1: Is the cold start most likely a choke problem?
Q2: Is the motor "bucking" maybe a fuel pump problem?
I had someone tell me that it could be related to motor mounts but......?
Thanks.
Senior User
Joined: Sep 1999
Posts: 176
Likes: 0
From: Minneapolis
Motor help please
Tell us more about your engine. Do you have stock cam? What kind of choke do you have, is it manual or electric??? What is your timing set at? How much vacuum are you pulling?
It all matters. It very well could be a choke problem. At start up on a cold day watch it to see if it is closed and how far. After warm up look at it again to see if it is opening. Also Holleys like to be played with as far as jetting and the squirters. Do you know if anything has been changed in the carb? Are you the original owner of the carb?
Also you need to see what your initial timing is and then look at your overall timing at about 3500-4000 rpm. It could be advanced too far. You would notice that by hard turnover at start up.
I'm sure you will get more feedback, but let us know as much as you can please.
It all matters. It very well could be a choke problem. At start up on a cold day watch it to see if it is closed and how far. After warm up look at it again to see if it is opening. Also Holleys like to be played with as far as jetting and the squirters. Do you know if anything has been changed in the carb? Are you the original owner of the carb?
Also you need to see what your initial timing is and then look at your overall timing at about 3500-4000 rpm. It could be advanced too far. You would notice that by hard turnover at start up.
I'm sure you will get more feedback, but let us know as much as you can please.
