 Yet another carb question? |
|
|
|
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. |
|
|
| JOE M |
 May 20 2008, 08:37 AM
Post
#1
|
|
Member  Group: Members Posts: 293 Joined: 27-August 07 From: N.H Member No.: 8,042 Region Association: None  |
I got my rebuild kit a few days ago and installed all the parts. I found that the kits came with the later model pump diaphram so I have to use my old pumps until I get the replacements. After about 30 minutes of tuning , the carbs seem to be working well. I still have some fine tuning. Prior to this I had a friend recheck my timing and valve adjsutmnts. All is well and compression is finally even all around about 110psi (still a little low).
So yesterday I started the car and began making some adjustments to the carbs. I turned the car aff and was checking for leaks and I heard a noise like fluid draining. I watched as gas filled each barrell. I am not sure why but after I stop the engine all the gas in the bowl leaks into the barrells (how is thisn possible??). This is happening on both carbs. Any thoughts?????? Thanks in advance. Forgot to say they are weber idf40 |
   |
 
|
  |
Replies(1 - 19)
| jmill |
May 20 2008, 10:25 AM
Post
#2
|
|
Green Hornet Group: Members Posts: 2,449 Joined: 9-May 08 From: Racine, Wisconsin Member No.: 9,038 Region Association: Upper MidWest |
Where is the fuel coming out? I can't be sure but, from you explaination, I'd say look at your accelerator pumps. It sounds like your draining down the float bowl through your accelerator pumps. Check to make sure you installed everything correctly. Is there little rubber check valves in your pumps? I don't know the IDF that well.
If this is the problem you'll be much leaner after the fix. Make sure your jetted properly. I've seen fuel puke out of carbs when the float level is set incorrectly or the needle doesn't seat well. This only happens when the fuel pump is running though. |
|
|
|
| JOE M |
May 20 2008, 12:09 PM
Post
#3
|
|
Member Group: Members Posts: 293 Joined: 27-August 07 From: N.H Member No.: 8,042 Region Association: None |
QUOTE(jmill @ May 20 2008, 08:25 AM)  Where is the fuel coming out? I can't be sure but, from you explaination, I'd say look at your accelerator pumps. It sounds like your draining down the float bowl through your accelerator pumps. Check to make sure you installed everything correctly. Is there little rubber check valves in your pumps? I don't know the IDF that well. If this is the problem you'll be much leaner after the fix. Make sure your jetted properly. I've seen fuel puke out of carbs when the float level is set incorrectly or the needle doesn't seat well. This only happens when the fuel pump is running though. It could be the pumps. The weird thing is that when the car is running all seems well. The car runs well and when I give it more gas it responds well. As soon as I kill the engine I can hear a hiss sound and I can see the gas filling above the throttle plate. I will take them apart again and verify how much fuel is actually filling the carb.I noticed this because I saw some smoke coming out of the barrells after I killed the engine.It kind of looks like a smog machine. It would be cool for halloween but I want to drive between now and than..LOL. |
|
|
|
| SLITS |
May 20 2008, 12:36 PM
Post
#4
|
|
"This Utah shit is HARSH!" Group: Benefactors Posts: 13,602 Joined: 22-February 04 From: SoCal Mountains ... Member No.: 1,696 Region Association: None  |
Ok, wild stab here .... if you do not have bakelite insulators between the manifolds and head you could feasilby get the carbatooters hot enough to volatize (boil) the fuel in the bowls and push it out the ports filling the venturis. Just a thought.
|
|
|
|
| jmill |
May 20 2008, 12:44 PM
Post
#5
|
|
Green Hornet Group: Members Posts: 2,449 Joined: 9-May 08 From: Racine, Wisconsin Member No.: 9,038 Region Association: Upper MidWest |
That would do it slits. The bowl would get pressurized and puke fuel out the mains. Thats why I asked him where it was coming from. Knowing the source would make finding the problem a lot easier.
|
|
|
|
| VaccaRabite |
May 20 2008, 12:57 PM
Post
#6
|
|
En Garde! Group: Admin Posts: 13,456 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region |
I just rebuilt mine as well, and put on the pheneolic spacers (how ever that is spelled.) Hopefully I won't have the same problem.
Sounds like it could be an explosive situation. Zach |
|
|
|
| purple |
May 20 2008, 01:12 PM
Post
#7
|
|
Pigeon feeders attract me Group: Members Posts: 938 Joined: 24-July 07 From: Houston, TX Member No.: 7,942 Region Association: None |
its funny, i had the phenolic spacers on my old single weber and it ran great. I switch to dual webers the thin gaskets (i broke the phenolics getting them off for a tin fix) and it runs like RUBBISH!
the plastic will help my carbatooters, you say? very fine! I have ordered my new carbatooter gaskets from pelicantooter parts. I hear they give you a better seal than the thin shit anyway. Any thoughts on that? |
|
|
|
| jmill |
May 20 2008, 01:27 PM
Post
#8
|
|
Green Hornet Group: Members Posts: 2,449 Joined: 9-May 08 From: Racine, Wisconsin Member No.: 9,038 Region Association: Upper MidWest |
Fuel needs to reach about 475 F before it flashes. I doubt the carb would get that hot. But as fuel temp increases so does its vapor pressure. Fuel would be pushed out of the jets instead of vacuum dragged if the bowl gets pressurized. It would make your carbs impossible to tune. Every carb I've dealt with has a vent on the bowl to prevent this. You might want to see if the vents are plugged.
|
|
|
|
| ericread |
May 20 2008, 01:31 PM
Post
#9
|
|
The Viper Blue 914 Group: Members Posts: 2,177 Joined: 7-December 07 From: Irvine, CA (The OC) Member No.: 8,432 Region Association: Southern California |
Carbatooters!
(IMG:style_emoticons/default/av-943.gif) PelicanTooter Parts (IMG:style_emoticons/default/av-943.gif) (IMG:style_emoticons/default/av-943.gif) I'm just glad I stayed with my FI. No carbatooters for me. No siree! |
|
|
|
| JOE M |
May 20 2008, 01:40 PM
Post
#10
|
|
Member Group: Members Posts: 293 Joined: 27-August 07 From: N.H Member No.: 8,042 Region Association: None |
QUOTE(ericread @ May 20 2008, 11:31 AM) Carbatooters! (IMG:style_emoticons/default/av-943.gif) PelicanTooter Parts (IMG:style_emoticons/default/av-943.gif) (IMG:style_emoticons/default/av-943.gif) I'm just glad I stayed with my FI. No carbatooters for me. No siree! I must be missing the joke --carbatooter and pelicantooter???? I need a good laugh fill me in. |
|
|
|
| purple |
May 20 2008, 01:40 PM
Post
#11
|
|
Pigeon feeders attract me Group: Members Posts: 938 Joined: 24-July 07 From: Houston, TX Member No.: 7,942 Region Association: None |
QUOTE(ericread @ May 20 2008, 02:31 PM) Carbatooters! (IMG:style_emoticons/default/av-943.gif) PelicanTooter Parts (IMG:style_emoticons/default/av-943.gif) (IMG:style_emoticons/default/av-943.gif) I'm just glad I stayed with my FI. No carbatooters for me. No siree! the previous owner made that choice for me. it had a weber carbatooter on there, a single progressive with a WATER CHOKE, however that F that works. My carbs are pretty painful to tune, but they are brand new. I think i need to set the float level and go down a size in idle jets. they are running wayyy too rich. the idle screws are almost all the way in, too. |
|
|
|
| ericread |
May 20 2008, 01:51 PM
Post
#12
|
|
The Viper Blue 914 Group: Members Posts: 2,177 Joined: 7-December 07 From: Irvine, CA (The OC) Member No.: 8,432 Region Association: Southern California |
QUOTE(JOE M @ May 20 2008, 12:40 PM) QUOTE(ericread @ May 20 2008, 11:31 AM) Carbatooters! (IMG:style_emoticons/default/av-943.gif) PelicanTooter Parts (IMG:style_emoticons/default/av-943.gif) (IMG:style_emoticons/default/av-943.gif) I'm just glad I stayed with my FI. No carbatooters for me. No siree! I must be missing the joke --carbatooter and pelicantooter???? I need a good laugh fill me in. Sorry. I guess I have a stange sense of humor (IMG:style_emoticons/default/screwy.gif) Come on now, "carbatooter" is funny stuff!!! (IMG:style_emoticons/default/av-943.gif) Just saying "Carbatooter" out loud makes me laugh!!! In my earlier days I spent endless hours rebuilding carbs, and identifying them as "carbatooters" cracks me up!!! .... it may be apparent that I don't get out much (IMG:style_emoticons/default/sad.gif) |
|
|
|
| jmill |
May 20 2008, 01:52 PM
Post
#13
|
|
Green Hornet Group: Members Posts: 2,449 Joined: 9-May 08 From: Racine, Wisconsin Member No.: 9,038 Region Association: Upper MidWest |
I love carbs myself. A simple jet change is much easier then changing injectors and remapping fuel curves. I does however take some tuning and tweaking. I've got a great book on the IDF at the house. If you still scratching your head tonight I'll help you out.
|
|
|
|
| SLITS |
May 20 2008, 01:53 PM
Post
#14
|
|
"This Utah shit is HARSH!" Group: Benefactors Posts: 13,602 Joined: 22-February 04 From: SoCal Mountains ... Member No.: 1,696 Region Association: None |
Ach, meine Himmel ....
I should have added that this condition would feasilby occur on engine shutdown. No longer is luft flowing across the heads so the heat transfer to the manifolds/carbatooters would be greater. |
|
|
|
| SirAndy |
May 20 2008, 01:58 PM
Post
#15
|
|
Resident German Group: Admin Posts: 41,669 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
QUOTE(ericread @ May 20 2008, 11:51 AM) .... it may be apparent that I don't get out much (IMG:style_emoticons/default/sad.gif) DING DING DING - WE HAVE A WINNER !!! (IMG:style_emoticons/default/smilie_pokal.gif) as for the carbs, i ran my dual 44 IDF with the thick stock FI insulator gaskets between the intake manifolds and the heads. it helped a lot to keep the heatsoak in check once the engine is turned off. as long as the engine is running, the draft will cool the carbs and manifolds. once you turn the engine off, you'll get heatsoak from the heads up the intake manifolds and into the carbs. if you only use the thin paper gaskets between the heads and manifolds, the manifolds will heat up much more and quicker ... (IMG:style_emoticons/default/bye1.gif) Andy |
|
|
|
| purple |
May 20 2008, 02:04 PM
Post
#16
|
|
Pigeon feeders attract me Group: Members Posts: 938 Joined: 24-July 07 From: Houston, TX Member No.: 7,942 Region Association: None |
So, Herr Andy,
Which would you recommend for a gaskatooter? The thick or the thin? |
|
|
|
| Elliot Cannon |
May 20 2008, 02:08 PM
Post
#17
|
|
914 Guru Group: Retired Members Posts: 8,487 Joined: 29-December 06 From: Paso Robles Ca. (Central coast) Member No.: 7,407 Region Association: None 
|
I better check my own carbetaters. I fixed my ideal jet clogging problem. It seems the fuel falter in the carb itself was clogled and no fuel could get through to volitalize. Volitazation is important!! That what cabetaters are for.
|
|
|
|
| SirAndy |
May 20 2008, 02:15 PM
Post
#18
|
|
Resident German Group: Admin Posts: 41,669 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
QUOTE(purple @ May 20 2008, 12:04 PM) So, Herr Andy, Which would you recommend for a gaskatooter? The thick or the thin? the thick FI insulator gaskets ... they come with a thick hard plastic core and two thin paper gaskets glued on each side. i put a thin layer of gasoline resistant RTV (GASP!!!) on each side and made sure the mating surface on the heads and intake manifolds was level and clean ... (IMG:style_emoticons/default/bye1.gif) Andy Attached image(s) 
|
|
|
|
| sww914 |
May 20 2008, 02:17 PM
Post
#19
|
|
Advanced Member Group: Members Posts: 2,439 Joined: 4-June 06 Member No.: 6,146 Region Association: None |
I have a pear of Webbberrz with the thickening pheoholic spasters and my many folds stay plenty cool. Running without the phenoholic spasters seems like a bad idea. Elliot, make sure that your falter holders are in there good, one of mine liberated it's self on the track and my car was crisping before I knew it. I put a bead of RTV around the head now just to make sure that they can't come loose anymore.
|
|
|
|
| purple |
May 20 2008, 02:18 PM
Post
#20
|
|
Pigeon feeders attract me Group: Members Posts: 938 Joined: 24-July 07 From: Houston, TX Member No.: 7,942 Region Association: None |
All this talk about carb teats and toots makes me want to go to the bathroom.
|
|
|
|
|
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 1st June 2024 - 12:54 PM |
Invision Power Board
v9.1.4 © 2024 IPS, Inc.