Weber 40IDF Help, Pump Jet Circuit Problem |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Weber 40IDF Help, Pump Jet Circuit Problem |
topatrout914 |
Apr 16 2008, 05:40 PM
Post
#1
|
Trout Group: Members Posts: 64 Joined: 13-October 06 From: Thomasville, NC Member No.: 7,034 Region Association: South East States |
I have set of used 40's that I rebuilt and I am having a problem with the pump jets dripping in both barrels at idle. This does of course make setting the mixture impossible and made for some large backfiring out of the exhaust on a quick ride arond the block. Can anyone tell me what might cause this?? The other carb works great and both were assembled at the same time and both floats are properly set. Help!! (IMG:style_emoticons/default/headbang.gif)
|
Mark Henry |
Apr 16 2008, 08:10 PM
Post
#2
|
that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
First guess....Check that the float (gross main jet) ball valves are closing fully.
also Check your pump pressure (3-5psi max) Check your float bowl level, could be to high. |
SGB |
Apr 16 2008, 08:28 PM
Post
#3
|
just visiting Group: Members Posts: 4,086 Joined: 8-March 03 From: Huntsville, AL Member No.: 404 Region Association: South East States |
My guess is the physical accel pump system. The little roller on the lever arm that rides a little cam between the barrels (down at the base) on the butterfly shaft gets gummed up and crudded causing dribbles and erratic accel pump actuation.
my 2 pesos... |
McMark |
Apr 16 2008, 09:32 PM
Post
#4
|
914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
Seems like all IDFs have this problem. (IMG:style_emoticons/default/dry.gif)
I agree with Scott that you can look at the linkage. Sometimes to vibration of the motor wiggles the linkage, which can be enough to cause little pump actions, which comes out as drips. Also, the float level has a 'trick'. You have to raise the float until it TOUCHES the ball, but does not depress the ball. |
topatrout914 |
Apr 17 2008, 07:06 AM
Post
#5
|
Trout Group: Members Posts: 64 Joined: 13-October 06 From: Thomasville, NC Member No.: 7,034 Region Association: South East States |
Thanks for the words of advice. I suppose I'll recheck the the float level and needle because I have seen an IDF flood because the float needle was not square on the seat. Fixed it by turing it around and putting the hanger on from the other side of the float lever. These carbs had a 24 hr solvent bath and all pieces and passages were blown out with compressed air so I am pretty certain it's not gunk or trash causing problems. Back to the garage!!
|
Mark Henry |
Apr 17 2008, 07:28 AM
Post
#6
|
that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
If you put an aftermarket carb kit in them the float valves that come with them are junk, try the old ones.
|
Lo-Fi Version | Time is now: 7th June 2024 - 11:14 PM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |