Re: surgung issue persists 340 4bbl
[Re: Mr.Yuck]
#325578
05/22/09 12:14 PM
05/22/09 12:14 PM
|
Joined: Jan 2003
Posts: 16,123 Grand Haven, MI
patrick
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
|
sheesh, not everything needs a frickin double pumper....
it's lean on the cruise circuit and/or too much advance on the cruise circut. on top of the carb, there should be 2 little metal plates held on by screws. are they flat or humped? if flat, they were changed to AFB parts, which will make finding replacement needles much easier. loosen the screws enough to rotate the cover out of the way and pull out the piston with the rods attached. if the rod does not have the dimensions stamped on it, take a caliper/mic and measure the diameter of the big diameter and the little diameter. if you have the humped covers, try calling some of the carb places (maybe demonsizzler on the board) and tell them you need a rod 1-2 sizes smaller on the big end and the same size little end for an AVS. or try buy some new flat rod covers (for an eddie AFB) or make your own out of some flat metal. now go look through the edelbrock catalog, find a rod with the same small diameter and 1-2 sizes smaller big diameter than your rod.
that will keep your power calibration the same, but richen up the cruise calibration slightly.
you could also try disconnecting and plugging the vaccuum advance from the distributor and see if that helps, but I doubt it, I think it's more that it's too lean at cruise with the upgraded cam.
another possibility, it could be the carb getting too hot. do you have a 3/8" thick insulator gasket between the carb and the intake?
Last edited by patrick; 05/22/09 12:16 PM.
1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!*** 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
|
|
|
Re: surgung issue persists 340 4bbl
[Re: patrick]
#325579
05/22/09 12:33 PM
05/22/09 12:33 PM
|
Joined: Oct 2007
Posts: 3,908 Oregon
hooziewhatsit
master
|
master
Joined: Oct 2007
Posts: 3,908
Oregon
|
I know you said you adjusted the Idle Mixture Screws, but I'd try doing it again, or, make them another 1/4 or 1/2 turn richer, and see if it changes.
On Edelbrocks site they list the cause of off-idle surging as the IMS screws being too rich or lean.
-Dave
If you ever find yourself in a fair fight, your tactics suck.
|
|
|
Re: surgung issue persists 340 4bbl
[Re: ashburnmike]
#325584
05/22/09 05:20 PM
05/22/09 05:20 PM
|
Joined: Nov 2003
Posts: 2,715 closer to Canadian beer!
torkrules
I'm neurotic
|
I'm neurotic
Joined: Nov 2003
Posts: 2,715
closer to Canadian beer!
|
Quote:
I am still experiencing a surging issue at a constant speed, in any gear on my car and looking for help to kill this problem. this is a...just put back on the road, '70 Dart Swinger, rebuilt 340 (stock guts w/a P4452759 cam, rebuilt (by Edelbrock thru Year One) Carter AVS #4937 4bbl, no a/c 4-speed car. It idles well It accelerates well. but it surges when i keep a steady petal. I have: replaced the plugs replaced the wires re-gapped the air gap on the distributor (I took the dual point out and installed a Mopar electronic ignition system) have the car timed @ 5 degrees BTDC retorqued the carburator retorqued the intake manifold sprayed starter fluid around the entire top of the motor looking for a vacuum leak- none found Adjusted the A/F mix per the Edelbrock carb manual which says to: turn one screw counter clockwise (rich) until maximum rpms are acheived, if there is a change of 45 rpms adjust the idle screw accordingly, then back the screw clockwise in (lean) just a touch. Repeat on the other A/F screw. I believe the vacuum hoses are all hooked up correctly. One runs from the drivers side valve cover to the base of the carb (thick hose) and the other runs from the base of the carb to the advance on the distributor (thin hose). The carb on the car does have what appears to be a fitting for a hose on the pass side of the carb next to the fuel inlet fitting. There is nothing connected to this fitting. The 4937 is not the correct carb for this cari It is for a '70 340 automatic w/ ECS. But it's all I have. It has been suggested that something is out of adjustment inside the carburator that is causing this surge issue. My weakest skill area.
Anyone have any thoughts or direction?
thanks
Mike
Could be the curve is too quick. This happened to me last year and took me forever to figure it out. If all else fails, try some heavier springs in the dist.
|
|
|
Re: surgung issue persists 340 4bbl
[Re: ashburnmike]
#325586
05/22/09 06:08 PM
05/22/09 06:08 PM
|
Joined: Nov 2006
Posts: 511 Jasper, Indiana
fastnos
mopar
|
mopar
Joined: Nov 2006
Posts: 511
Jasper, Indiana
|
One other thing to check. When sitting with a timing light on it, if you hold it @ (any RPM it acts up) does your timing mark jump around, or is it steady within 1-2 degrees? If it jumps excessively, might be worn timing chain/gears. Just a thought...
A True Hybrid: Burns Gas AND Rubber!
|
|
|
Re: surgung issue persists 340 4bbl
[Re: ashburnmike]
#325588
05/22/09 10:03 PM
05/22/09 10:03 PM
|
Anonymous
Unregistered
|
Anonymous
Unregistered
|
Try taking a ride with vacuum advance un-hooked.
|
|
|
Re: surgung issue persists 340 4bbl
[Re: ph23vo]
#325591
05/22/09 11:57 PM
05/22/09 11:57 PM
|
Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
Circle Track
|
Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
|
I hope it's not rotor phasing. I cant handle another rotor phasing thread.
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: surging issue persists 340 4bbl
[Re: ashburnmike]
#325593
05/23/09 12:28 AM
05/23/09 12:28 AM
|
Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
Circle Track
|
Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
|
always make (1) change at a time
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: surgung issue persists 340 4bbl
[Re: Mr.Yuck]
#325594
05/23/09 06:00 AM
05/23/09 06:00 AM
|
Joined: Jul 2008
Posts: 30,486 Florida STAYcation
dOc …
The village idiot's idiot
|
The village idiot's idiot
Joined: Jul 2008
Posts: 30,486
Florida STAYcation
|
Quote:
lean.... fatten it up...or better yet get a DP.
A DP ? ... yeah "pump" this !! ...
The BESTer solution would be to put a PlasticFantastic on it !
With a TQ ... just a turn or so on the "tree" and you would be all set !! ..... and get LOTS better MPG to boot.
|
|
|
|
|