How do you find a Good Mechanic?
Le Mans Master
Joined: Aug 2010
Posts: 9,272
Likes: 17
6 degrees before TDC gets you in the ball park, popping under load could be a bunch of things, idles fine , revs fine with out load, and then popping and coughing under load, usually, but not always ignition. dizzy not advancing. Timing light would help with that. Best check you could do would be a vacume check to verify valve train. you wont get high and steady depending on the cam, but its a place to start. Actually sounds like crossfireing under load. carbon tracks in the dizzy cap. plug wire boots not sealing, cheap wires. it goes on and on. Start with the free fixes and work your way thru. could even be a plugged fuel filter.
Drifting
Joined: Dec 2004
Posts: 1,714
Likes: 42
From: Austin Texas
Two things.
1. It sounds like you are already as good as most mechanics you will find, you are just up against a wall. If you have a good dial back timing light, you have the tools you need. Don't give up now.
2. I had this problem with my car when I made some changes too.
Try to disconnect the vacuum advance, plug the port on carb and test drive. (there are several things it could be but this one helped me) This will "help" isolate if your issue is timing or air/fuel.
My quadrajet ran great with manifold vacuum for the advance. I switched to a Holley and it surged with manifold vacuum advance. I switched it to ported and it ran like EFI. If disconnecting the advance helps the surge, try to plug it into a ported vacuum source and test drive. Just try it if you haven't already and let us know the results.
There is a great sticky thread on timing. Your goal is 34-36 deg adv without vacuum adv. To get to this, it is likely your initial will need to be in the low teens ( i am set at 12).
http://forums.corvetteforum.com/c3-t...long-post.html
1. It sounds like you are already as good as most mechanics you will find, you are just up against a wall. If you have a good dial back timing light, you have the tools you need. Don't give up now.
2. I had this problem with my car when I made some changes too.
Try to disconnect the vacuum advance, plug the port on carb and test drive. (there are several things it could be but this one helped me) This will "help" isolate if your issue is timing or air/fuel.
My quadrajet ran great with manifold vacuum for the advance. I switched to a Holley and it surged with manifold vacuum advance. I switched it to ported and it ran like EFI. If disconnecting the advance helps the surge, try to plug it into a ported vacuum source and test drive. Just try it if you haven't already and let us know the results.
There is a great sticky thread on timing. Your goal is 34-36 deg adv without vacuum adv. To get to this, it is likely your initial will need to be in the low teens ( i am set at 12).
http://forums.corvetteforum.com/c3-t...long-post.html
Last edited by johnt365; May 18, 2012 at 08:58 AM.
Racer
Joined: Apr 2012
Posts: 465
Likes: 18
From: NorthEast
When I get beyond my known capabilities to wrench, I use a local guy. He has a classic 69 Stang he wrenches on and has several clients that own classic cars that bring them to him. That being said, I am increasing my wrench abilities and use the forum for A LOT of help. I know when I get to the point that it's beyond me, but I'm working on lessening those times. Heck I just fixed an electrical problem on my truck because of what I learned and read here. I took my stock Q-jet after replacing it, cleaned it, tore it down, put it back together, just to learn.
Good advice is continue to develop your skills, know when your over your head, and definitely talk to the old guys at a show or cruise night. Whenever I have done that, these guys love to talk cars.
Oh yeah, the guys on the forum and their knowledge......priceless. Glad I found this place.
Good luck man.
Good advice is continue to develop your skills, know when your over your head, and definitely talk to the old guys at a show or cruise night. Whenever I have done that, these guys love to talk cars.
Oh yeah, the guys on the forum and their knowledge......priceless. Glad I found this place.
Good luck man.
