Help needed on a engine dying problem.
Thread Starter
Virtual George
Joined: Dec 1999
Posts: 423
Likes: 12
From: Gainesville Georgia
Navy
Help needed on a engine dying problem.
I need advise on an engine problem that is evading me. I was out driving my 67 327/350 and it started dying on me every time I let off the gas. I keep the RPM’s up enough to get it home and on the rack.
I use to have a similar problem that was caused by the distributor covers, so I took them off first but the problem was still there. I started trying to figure out if it was Electrical or Fuel related, which is usually easy, but not this time.
It starts fine but starts dying out after about 2 seconds. I adjusted the idle up enough to keep it running so that I could look at the problem. If it dies, it starts again fine. I looked at the voltage on the plus side of the coil and I don’t see a drop out. I put a timing light on and watched the light and I don’t see a drop out. I start thinking its fuel related. I watched the carb and it’s hard to tell if the fuel is stopping.
I replaced the fuel filter to make sure. I did a body off less than two years ago and put new everything including the tank and lines and pump, but used the old carb.
Still I have the problem. I guess I’m having a brain fade type of day. Can anyone jump in with some ideas on how to figure this out….please.
VG
I use to have a similar problem that was caused by the distributor covers, so I took them off first but the problem was still there. I started trying to figure out if it was Electrical or Fuel related, which is usually easy, but not this time.
It starts fine but starts dying out after about 2 seconds. I adjusted the idle up enough to keep it running so that I could look at the problem. If it dies, it starts again fine. I looked at the voltage on the plus side of the coil and I don’t see a drop out. I put a timing light on and watched the light and I don’t see a drop out. I start thinking its fuel related. I watched the carb and it’s hard to tell if the fuel is stopping.
I replaced the fuel filter to make sure. I did a body off less than two years ago and put new everything including the tank and lines and pump, but used the old carb.
Still I have the problem. I guess I’m having a brain fade type of day. Can anyone jump in with some ideas on how to figure this out….please.
VG
Tech Contributor
Joined: May 2005
Posts: 15,576
Likes: 118
From: Conroe Texas
Thread Starter
Virtual George
Joined: Dec 1999
Posts: 423
Likes: 12
From: Gainesville Georgia
Navy
That all sounds like what I'm thinking also. I think that old carb has seen it's days. Time for something shiny and new. (it's not an original)
What carb would you suggest?
I'm thinking a 650 Holley.
VG
What carb would you suggest?
I'm thinking a 650 Holley.
VG
Drifting
Joined: Apr 2001
Posts: 1,401
Likes: 9
From: Holly Springs, Nort Cackalacky / Jupiter, Florida
Depends on how original you want to appear.
http://cgi.ebay.com/ebaymotors/64-65...9199QQtcZphoto
But I would add you should do some simple checking before you just put the toe tag on your current carb.
http://cgi.ebay.com/ebaymotors/64-65...9199QQtcZphoto
But I would add you should do some simple checking before you just put the toe tag on your current carb.
Last edited by RoadKing96; Jul 18, 2008 at 09:56 AM.
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From: Conroe Texas
Safety Car
Joined: Feb 2003
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From: St. Joseph Mo
Thread Starter
Virtual George
Joined: Dec 1999
Posts: 423
Likes: 12
From: Gainesville Georgia
Navy
I went shopping on the Holley site. What do you think of this one in a 650?
http://www.holley.com/types/Street%20Avenger.asp
I like to keep the original look, but not so that it would bother me too much. It hides under the air cleaner anyhow.
VG
http://www.holley.com/types/Street%20Avenger.asp
I like to keep the original look, but not so that it would bother me too much. It hides under the air cleaner anyhow.
VG
Team Owner
Joined: Mar 2003
Posts: 26,118
Likes: 1,874
From: Greenville, Indiana
If it was a fuel starvation problem, it's not likely it would start right back up unless you were pumping the gas. If the carb was dry, it wouldn't start that way because there's no gas to pump.
If it was a fuel starvation problem, raising the idle speed wouldn't help, it'd die anyway.
If the carb was flooding, you'd have to hold the gas down to start it. Raising the idle speed would help this situation keeping it running.
If you had a vacuum leak, the engine would/could die at a slow idle speed. Raising the idle speed would help keep it running. With a vacuum leak, you could restart the engine after it died with no problem.
How about some more details?
If it was a fuel starvation problem, raising the idle speed wouldn't help, it'd die anyway.
If the carb was flooding, you'd have to hold the gas down to start it. Raising the idle speed would help this situation keeping it running.
If you had a vacuum leak, the engine would/could die at a slow idle speed. Raising the idle speed would help keep it running. With a vacuum leak, you could restart the engine after it died with no problem.
How about some more details?
Thread Starter
Virtual George
Joined: Dec 1999
Posts: 423
Likes: 12
From: Gainesville Georgia
Navy
I do pump before starting.
It starts fine and for about a second or two it runs fine. Then you can hear the rpm's start to drop. If you give it more gas, it will keep running.
So, running down the road, it runs ok until you let off the gas and then it dies. I'm thinking the higher rpm's while driving are getting it through the drop-outs.
It's the cause of the drop-outs that is giving me fits.
The engine sounds fine until the drop-outs. Then it sound like it is just losing power and the RPM's start to drop.
VG
It starts fine and for about a second or two it runs fine. Then you can hear the rpm's start to drop. If you give it more gas, it will keep running.
So, running down the road, it runs ok until you let off the gas and then it dies. I'm thinking the higher rpm's while driving are getting it through the drop-outs.
It's the cause of the drop-outs that is giving me fits.
The engine sounds fine until the drop-outs. Then it sound like it is just losing power and the RPM's start to drop.
VG
Team Owner
Joined: Mar 2003
Posts: 26,118
Likes: 1,874
From: Greenville, Indiana
Do you pump the gas with the engine hot? Cold? Just after it dies? After it dies with the engine warm, will it restart without pumping the gas?
[QUOTE=VG;1566354660]I do pump before starting.
[QUOTE=VG;1566354660]I do pump before starting.
Thread Starter
Virtual George
Joined: Dec 1999
Posts: 423
Likes: 12
From: Gainesville Georgia
Navy
Well pumping the gas is a gray term.
I always give it some gas on a start up.
I usually give it more on a cold start.
It's one of those things us old guys never think about anymore, we just know how much to give it.
Note, I let it go cold overnight and on start, I had the problem right away.
I do give it some gas on a cold start, but not a full pump.
VG
I always give it some gas on a start up.
I usually give it more on a cold start.
It's one of those things us old guys never think about anymore, we just know how much to give it.
Note, I let it go cold overnight and on start, I had the problem right away.
I do give it some gas on a cold start, but not a full pump.
VG
Safety Car
Joined: Jun 2003
Posts: 3,596
Likes: 8
From: Grosse Ile MI
Sounds like something (dirt, varnish?) is blocking the idle circuit of the carb causing a lean condition and once you open the throttle plates past the transfer slots, you're off the idle circuit and the primary circuit is supplying all the fuel the engine needs to run normally. And that's my best guess. Hope you find the problem soon.
Dave
Dave
You don't need a 750
Team Owner
Joined: Mar 2003
Posts: 26,118
Likes: 1,874
From: Greenville, Indiana
Sounds like something (dirt, varnish?) is blocking the idle circuit of the carb causing a lean condition and once you open the throttle plates past the transfer slots, you're off the idle circuit and the primary circuit is supplying all the fuel the engine needs to run normally. And that's my best guess. Hope you find the problem soon.
Dave
Dave
Agree with this as a best guess.The 750 Holley is bigger than you need but they will run well on your engine as long as it's jetted correctly and the right spring is in the vacuum secondaries. I don't know anything about the double pumper carbs if that's what it is
You seem intent on replacing what you have. I'd fix it. Can't be much of anything wrong.