General Tech Good at troubleshooting? Have a non-specific issue? Discuss general tech topics here. IF YOUR QUESTION IS SPECIFIC TO A CERTAIN MODEL, IT DOES NOT GO IN THIS SECTION.
Sponsored by:
Sponsored by: CARiD

Need some help timing a 250 inline 6 chevy motor.

Thread Tools
 
Search this Thread
 
Old Apr 14, 2017 | 5:52 PM
  #21  
kevinkpk's Avatar
CF Monarch
10 Year Member
Liked
 
Joined: Jul 2011
Posts: 5,920
Likes: 140
From: kevinkpk
Default

The cam follower on the points is mica, non conductive. If you don't have any play from the bottom of the shaft (cam gear) to the top, point cam, it's ok. My take looking at it is the points are not secure with the screw holding them down, does it screw down tight?
Reply
Old Apr 14, 2017 | 6:03 PM
  #22  
JeffRil's Avatar
Thread Starter
CF Beginner
 
Joined: Mar 2017
Posts: 16
Likes: 0
Default

Yea its tight, i can pick up on the top of the cam and it has some play up and down but not side to side Pulled up.
Pushed down.
Reply
Old Apr 14, 2017 | 7:06 PM
  #23  
kevinkpk's Avatar
CF Monarch
10 Year Member
Liked
 
Joined: Jul 2011
Posts: 5,920
Likes: 140
From: kevinkpk
Default

Take a feeler gauge, and gap them to .017-.018"
Reply
Old Apr 14, 2017 | 9:34 PM
  #24  
JeffRil's Avatar
Thread Starter
CF Beginner
 
Joined: Mar 2017
Posts: 16
Likes: 0
Default

Originally Posted by kevinkpk
Take a feeler gauge, and gap them to .017-.018"
I have, then when I check the dwell it is at 25 degrees, but it seems to run great on that.
Reply
Old Apr 14, 2017 | 9:45 PM
  #25  
kevinkpk's Avatar
CF Monarch
10 Year Member
Liked
 
Joined: Jul 2011
Posts: 5,920
Likes: 140
From: kevinkpk
Default

Leave it there as it looks like you have to take a screwdriver to step it into dwell, in other words, there used to be more readily available point/conderser that had an allen head that you could set the dwell with it running. Setting the gap at .017 is fine
Reply
Old Apr 23, 2017 | 5:14 PM
  #26  
JeffRil's Avatar
Thread Starter
CF Beginner
 
Joined: Mar 2017
Posts: 16
Likes: 0
Default

So I really need some help now, I had dropped the gap in the points to 0.010 and it got to a 31 degree dwell, but it run like crap, so i put it back to what it was running before and now it has some power in 1st gear and second gear but when it hits third and accelerating it starts bucking and loses power, I didnt mess with anything other than the points and they are gapped to 0.017 now, this thing really has me stumped but at the moment its my only means of transportation, if anyone can tell me whats happening i would appreciate it.
Reply
Old Apr 23, 2017 | 5:27 PM
  #27  
kevinkpk's Avatar
CF Monarch
10 Year Member
Liked
 
Joined: Jul 2011
Posts: 5,920
Likes: 140
From: kevinkpk
Default

Ok, once again. put the cam point of the cam of the distributor on the high point of the mica arm on the points. With the #1 cylinder at top dead center or there abouts, open the set screw on the base of the points till you have around ".017 inch. This should get you close.
Reply
Old Apr 24, 2017 | 4:04 AM
  #28  
oldchevy's Avatar
CF Monarch
10 Year Member
Liked
 
Joined: Apr 2012
Posts: 6,216
Likes: 438
From: Miami, FL.
Default

Your dwell meter could be out of calibration. Set as close as you can with the feeler gauge and leave it there. You said it runs the best at that setting anyway.
Reply
Old Apr 29, 2017 | 9:48 AM
  #29  
JeffRil's Avatar
Thread Starter
CF Beginner
 
Joined: Mar 2017
Posts: 16
Likes: 0
Default

Ok guys I dove into this a little more, pulled the distributor and found that the roll pin was worn so the drive gear was lose side to side, so I replaced the roll pin now the gear is tight, but still had the motor shaking when accelerating so I started pulling vac hoses, I got to the vapor canister that has a removable top where the carb line goes in, the diaphragm inside was ripped, so I'm in the process of trying to get that fixed, can't afford a new canister at the moment, but I added a pic of the distributor with the gear removed.
Reply
Old May 8, 2017 | 2:35 AM
  #30  
JeffRil's Avatar
Thread Starter
CF Beginner
 
Joined: Mar 2017
Posts: 16
Likes: 0
Default

Ok so here is a bit of an update, i got the timing mark to stop jumping, i changed the points and also the vac line from the manifold to the break booster was cracked and missing a clamp i got a new piece of hose and some clamps and now 99% of the time the timing mark is right on, after that i set the timing mark to 8 degrees that is says to on the sticker under the hood and it stopped the backfire it was having at idle, the only problem I am having now is when i accelerate to 55 or 60 the motor bucks like it loses power, if I tromp on the gas to accelerate fast it bucks at 38, but when breaking at any speed it backfires but not any other time, I'm thinking something is wrong with the carb but i just put a rebuild kit into it, i did however a few weeks ago when trying to get the dwell set right i had to set the points to 0.010 to get the dwell to 31 degrees, when i did this it ran for a bit and then made a loud pop from the carb and shut off, i dont know what the bucking is caused from though, anyone have any ideas?
Reply




All times are GMT -5. The time now is 8:20 PM.