burndup
09-11-2003, 02:48 PM
For those with short term memroy loss, its a 66 429... pertronix ignition...
No pictures until its "Finished," been putting many hours in on the thing. Looking better, at least.
Following description applies on 85deg plus days...
OK, after ya start it up from cold, it runs great. Fine. No trouble for many many miles. Then, if ya Park it for a few minutes and then try and start it again, it all goes to shit. Too rich, hard to get running. runs like crap. BUT, once some air gets moving into the engine compartment, its starts running better, almost perfectly. I caught a good whiff of the exhaust, definately rich.
Running in traffic sometimes brings it about too.
Here's whats been replaced, fuel system wise..
new and well sealed intake manifold gaskets
Known good 650 cfm edelbrock AFB carb (according to Creeper Larry!)
LARGE new air cleaner/filter
Teflon spacer under the carb instead of phenolic stocker...
All new rubber fuel line throught system
New gas
Fuel pressure seems fine... Now, yesterday, I had a first... I could actually SMELL gas from the carb, so maybe this ones got a bad float... or can vacuum alone pull gas from the bowl thru the overflows??????
There is some sort of "return line" that goes from the top of the fuel filter/sediment bowl... today I'm gonna see if its blocked, perhaps I'm getting TOO much fuel pressure if it is???
Now, DrJ had this theory that the valves had dropped into the seats, making the stems too long, causeing the exhaust valves to stay open too long, causing loss of power.... thisa wouldn't make it RICH, would it? I haven't measured the clearance, this seems like just too much of a longshot. In the back of my mind, all the same.
BIG DUMB QUESTION... the mixture screws are only relavant for IDLE, right? not general operation? That is how I understand it, I'll feel pretty dumb if turning down some screws fixes my shit...
Another... doing the equation says that 600 cfm isn't undercarbing a 429... now this aint a drag motor... But is there such a thing as an engine that pulls more vacuum than a carb can handle? wouldn't that result in a LEAN condition??
Whats envolved with leaning down the carb? new metering rods?
What kinds of things in general causes a rich condition??? I wann run over the entire gamut.
Thoughts? ideas?
Thanks,
No pictures until its "Finished," been putting many hours in on the thing. Looking better, at least.
Following description applies on 85deg plus days...
OK, after ya start it up from cold, it runs great. Fine. No trouble for many many miles. Then, if ya Park it for a few minutes and then try and start it again, it all goes to shit. Too rich, hard to get running. runs like crap. BUT, once some air gets moving into the engine compartment, its starts running better, almost perfectly. I caught a good whiff of the exhaust, definately rich.
Running in traffic sometimes brings it about too.
Here's whats been replaced, fuel system wise..
new and well sealed intake manifold gaskets
Known good 650 cfm edelbrock AFB carb (according to Creeper Larry!)
LARGE new air cleaner/filter
Teflon spacer under the carb instead of phenolic stocker...
All new rubber fuel line throught system
New gas
Fuel pressure seems fine... Now, yesterday, I had a first... I could actually SMELL gas from the carb, so maybe this ones got a bad float... or can vacuum alone pull gas from the bowl thru the overflows??????
There is some sort of "return line" that goes from the top of the fuel filter/sediment bowl... today I'm gonna see if its blocked, perhaps I'm getting TOO much fuel pressure if it is???
Now, DrJ had this theory that the valves had dropped into the seats, making the stems too long, causeing the exhaust valves to stay open too long, causing loss of power.... thisa wouldn't make it RICH, would it? I haven't measured the clearance, this seems like just too much of a longshot. In the back of my mind, all the same.
BIG DUMB QUESTION... the mixture screws are only relavant for IDLE, right? not general operation? That is how I understand it, I'll feel pretty dumb if turning down some screws fixes my shit...
Another... doing the equation says that 600 cfm isn't undercarbing a 429... now this aint a drag motor... But is there such a thing as an engine that pulls more vacuum than a carb can handle? wouldn't that result in a LEAN condition??
Whats envolved with leaning down the carb? new metering rods?
What kinds of things in general causes a rich condition??? I wann run over the entire gamut.
Thoughts? ideas?
Thanks,