Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
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.
 

Welcome Guest ( Log In | Register )

> Carb throat popping at speed, New Problem!!!
LetoAtreides
post Aug 15 2008, 10:38 PM
Post #1


Member
**

Group: Members
Posts: 86
Joined: 15-May 07
From: Half Moon Bay, California
Member No.: 7,739
Region Association: None



Ok, so I know I've posted this before, but I still cant figure it out, and I need to know all of the possible circumstances under which this condition occurs.

One of the throads on my dual carbs is excessively lout at speed. It sounds like pop-pop-pop.

Any ideas?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
 
Reply to this topicStart new topic
Replies
LetoAtreides
post Aug 20 2008, 05:26 PM
Post #2


Member
**

Group: Members
Posts: 86
Joined: 15-May 07
From: Half Moon Bay, California
Member No.: 7,739
Region Association: None



Sorry for testing your patience, ArtechnikA, let me explain myself.

I'm 19 years old and learning to work on my own car. I learned this supposed timing technique from my neighbor who has worked on old cars his entire life. I don't have the cash to take it into my mechanic, so I have to learn to do this myself.

I static timed the car (and subsequently shocked myself with my home-made timing light). I timed it to the advanced mark on my fan. There's no change in the carburetor noise. Tomorrow i will borrow my neighbor's timing light and time it.

Is there any way to tell if my engine is permanently damaged?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
ArtechnikA
post Aug 20 2008, 07:07 PM
Post #3


rich herzog
*****

Group: Members
Posts: 7,390
Joined: 4-April 03
From: Salted Roads, PA
Member No.: 513
Region Association: None



QUOTE(LetoAtreides @ Aug 20 2008, 07:26 PM) *

I'm 19 years old and learning to work on my own car.


BTDT, believe me. I'm sure many if not most here have been.
However, when I was 19 and just starting out with cars (VW's first, fairly quickly into old Porsches) there were no resources like the Internet and this site. We were happy to pick up a copy of John Muir's 'Idiot Book' (I started -before- that classic reference...) and maybe a Clymer's.

The are probably a few dozen threads on this site alone about 'How do I time a 914.' So there is really no excuse for not doing one's research first.

So - moving on...

QUOTE
I learned this supposed timing technique from my neighbor who has worked on old cars his entire life.
Specifically, old WATER-COOLED cars with a big carb in the middle. You could maybe get away with it there if you were careful.

QUOTE
I static timed the car (and subsequently shocked myself with my home-made timing light). I timed it to the advanced mark on my fan.

Alrighty - plus or minus not enough to matter, you're running about 28 degrees initial and 36 total. WAY TOO MUCH!. Go static-time it a smidge before the TDC mark for #1.

QUOTE
Is there any way to tell if my engine is permanently damaged?
Bring -everything- to book specs and listen real close. A compression and/or leakdown test would confirm findings if you had obvious bad running or clouds of smoke. We'll hope for the best.

Seriously - DO THE SEARCH here on timing your car. There are threads in great detail about the process.

Mostly, I don't do T-IV's so I am really unqualified to provide additional details, besides which, they're already out there. I got into this thread because of the induction linkage aspect, which I -am- qualifed to explore.

Good luck.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post

Posts in this topic
LetoAtreides   Carb throat popping at speed   Aug 15 2008, 10:38 PM
r_towle   well, its lean. How it has become lean could be al...   Aug 15 2008, 11:13 PM
drive-ability   Ok, so I know I've posted this before, but I ...   Aug 15 2008, 11:14 PM
Elliot Cannon   If it accelerates OK but starts popping when you a...   Aug 15 2008, 11:23 PM
ArtechnikA   also - check for bad, bent, or misaligned linkage....   Aug 16 2008, 09:10 AM
LetoAtreides   Update! I adjusted the linkage on one side, a...   Aug 16 2008, 04:57 PM
LetoAtreides   So i think I've pretty much fixed my popping p...   Aug 20 2008, 12:56 PM
r_towle   What is your timing set at??? Rich   Aug 20 2008, 01:11 PM
LetoAtreides   I timed it using an electronic tach. I rotated th...   Aug 20 2008, 02:15 PM
ArtechnikA   Normally I am a very patient person but this has p...   Aug 20 2008, 03:26 PM
Mark Henry   I understand how Rich feels, the T4 doesn't li...   Aug 20 2008, 03:39 PM
LetoAtreides   Sorry for testing your patience, ArtechnikA, let m...   Aug 20 2008, 05:26 PM
ArtechnikA   I'm 19 years old and learning to work on my o...   Aug 20 2008, 07:07 PM
LetoAtreides   Thanks for the info. How much is a smidge? is i...   Aug 20 2008, 10:32 PM
r_towle   I will try to clarify. Step one. Static time the ...   Aug 20 2008, 10:52 PM
LetoAtreides   Ok, cool. I checked the points and dwell angle ve...   Aug 20 2008, 11:03 PM
ArtechnikA   27, 28 - that's probably as close as most of u...   Aug 21 2008, 06:47 AM
rhodyguy   i suggest you limp or tow your car to High Perfoma...   Aug 21 2008, 09:15 AM
LetoAtreides   Yeah, I've done business with Rich, and he...   Aug 21 2008, 01:39 PM
LetoAtreides   Ok, so I timed my car by the book, and it idles a ...   Aug 22 2008, 05:17 PM
ArtechnikA   Ok, so I timed my car by the book, and it idles a...   Aug 22 2008, 06:28 PM
LetoAtreides   Dellorto: main jet 36 Venturii 140 I don't kn...   Aug 22 2008, 09:20 PM
ArtechnikA   Dellorto: main jet 36 Venturii 140 Ahhh - no. Th...   Aug 23 2008, 07:00 AM
LetoAtreides   Ok, sorry about the bogus numbers. I thought the ...   Aug 23 2008, 10:39 AM
LetoAtreides   Ok, main jet is 140 pump jet is 35 I'll have t...   Aug 23 2008, 10:48 AM
LetoAtreides   idle jet is 55 throat is 40 sparks are nice and b...   Aug 23 2008, 05:28 PM
ArtechnikA   Tried driving it a bit today and no backfires whi...   Aug 24 2008, 07:09 AM
rhodyguy   what are the flow #s as indicated on your synchron...   Aug 24 2008, 07:46 AM


Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



- Lo-Fi Version Time is now: 4th June 2025 - 01:42 PM