Author |
Message |
SlowRhode Samba Member
Joined: July 05, 2018 Posts: 12 Location: Providence, RI
|
Posted: Thu Jun 24, 2021 10:20 pm Post subject: Hesitation, bucking, loss of power 72 dual carbs [SOLVED] |
|
|
Only seems to happen when warm (after running for 15 minutes or so)
In 3rd/4th gear I get a sudden drop in power, barley able to climb hills. At highway speeds it will drop to 45-50 MPH.
Im running dual solex 40/44 eis carburetors & electric fuel pump. Running a pentronix ignition in lieu of points.
I just pulled the engine to replace the clutch and this has started occurring since then (earlier this week).
So far I have:
Replaced the fuel filters (a little dirty but didnt seem overtly bad)
Replaced the coil
Pulled carbs and cleaned them (little dirty in the bowls)
Rechecked all my connections
Am I missing something major here? Im thinking next step is to drain the fuel tank and check the sock?
Any help would be super appreciated! Pretty stumped!
Last edited by SlowRhode on Sun Jun 27, 2021 12:03 pm; edited 1 time in total |
|
Back to top |
|
|
Wildthings Samba Member
Joined: March 13, 2005 Posts: 50254
|
Posted: Fri Jun 25, 2021 1:36 am Post subject: Re: Hesitation, bucking, loss of power 72 dual carbs |
|
|
If your fuel tank venting properly?
Set your timing to 28° BTDC @ 3800+ rpms, hoses off and plugged. |
|
Back to top |
|
|
SlowRhode Samba Member
Joined: July 05, 2018 Posts: 12 Location: Providence, RI
|
Posted: Fri Jun 25, 2021 3:21 am Post subject: Re: Hesitation, bucking, loss of power 72 dual carbs |
|
|
Wildthings wrote: |
If your fuel tank venting properly?
Set your timing to 28° BTDC @ 3800+ rpms, hoses off and plugged. |
Tried driving without gas cap and no change. I will attempt to reset my timing to those specs but I did try altering timing a few times with no luck. |
|
Back to top |
|
|
SlowRhode Samba Member
Joined: July 05, 2018 Posts: 12 Location: Providence, RI
|
Posted: Fri Jun 25, 2021 10:56 am Post subject: Re: Hesitation, bucking, loss of power 72 dual carbs |
|
|
Can pertronix ignitor go bad in a way that it starts to fail when engine is warm?
Ordered a replacement (and replacement distributor as well) but I really hate throwing parts at a problem. |
|
Back to top |
|
|
busdaddy Samba Member
Joined: February 12, 2004 Posts: 51057 Location: Surrey B.C. Canada, but thinking of Ukraine
|
Posted: Fri Jun 25, 2021 11:14 am Post subject: Re: Hesitation, bucking, loss of power 72 dual carbs |
|
|
SlowRhode wrote: |
Can pertronix ignitor go bad in a way that it starts to fail when engine is warm?
Ordered a replacement (and replacement distributor as well) but I really hate throwing parts at a problem. |
Yes, it usually starts as a miss on the highway, much like fuel starvation. _________________ Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
|
Back to top |
|
|
timvw7476 Samba Member
Joined: June 03, 2013 Posts: 2180 Location: seattle
|
Posted: Fri Jun 25, 2021 11:30 am Post subject: Re: Hesitation, bucking, loss of power 72 dual carbs |
|
|
SlowRhode wrote: |
Can pertronix ignitor go bad in a way that it starts to fail when engine is warm?
Ordered a replacement (and replacement distributor as well) but I really hate throwing parts at a problem. |
Rockauto will deliver WVE brand points & condenser for $12.84.
I have no experience with WVE points & condenser, but I would use them
as a substitute for the Pertronix ignitor to troubleshoot. Cheapest diagnostic path I know of. That's assuming your ignition coil will tolerate points, maybe you have a proprietary Pertronix coil as well & no old points style to substitute? |
|
Back to top |
|
|
SlowRhode Samba Member
Joined: July 05, 2018 Posts: 12 Location: Providence, RI
|
Posted: Fri Jun 25, 2021 11:55 am Post subject: Re: Hesitation, bucking, loss of power 72 dual carbs |
|
|
timvw7476 wrote: |
SlowRhode wrote: |
Can pertronix ignitor go bad in a way that it starts to fail when engine is warm?
Ordered a replacement (and replacement distributor as well) but I really hate throwing parts at a problem. |
Rockauto will deliver WVE brand points & condenser for $12.84.
I have no experience with WVE points & condenser, but I would use them
as a substitute for the Pertronix ignitor to troubleshoot. Cheapest diagnostic path I know of. That's assuming your ignition coil will tolerate points, maybe you have a proprietary Pertronix coil as well & no old points style to substitute? |
I actually was able to buy points and a new pertronix off of Amazon and its arriving tomorrow. I had the same thought about helping diagnosing 👍 |
|
Back to top |
|
|
airschooled Air-Schooled
Joined: April 04, 2012 Posts: 12686 Location: on a bike ride somewhere
|
Posted: Fri Jun 25, 2021 12:03 pm Post subject: Re: Hesitation, bucking, loss of power 72 dual carbs |
|
|
All hail Lord Bezos. _________________ Learn how your vintage VW works. And why it doesn't!
One-on-one tech help for your Volkswagen:
www.airschooled.com |
|
Back to top |
|
|
SlowRhode Samba Member
Joined: July 05, 2018 Posts: 12 Location: Providence, RI
|
Posted: Sun Jun 27, 2021 12:06 pm Post subject: Re: Hesitation, bucking, loss of power 72 dual carbs [SOLVED] |
|
|
So pulled the carburetors again while waiting for our lord and savior Jeffrey Bezos to deliver my parts.
Drivers side carb needle valve was coming apart. I peened back the edge a little to keep the spring/internal needle inserted. Runs 100% while I wait for a new needle valve.
Thanks everyone for your help! |
|
Back to top |
|
|
69BahamaYellow Samba Member
Joined: April 22, 2011 Posts: 535 Location: Talbott, TN
|
Posted: Sun Jun 27, 2021 7:43 pm Post subject: Re: Hesitation, bucking, loss of power 72 dual carbs [SOLVED] |
|
|
Thanks for sharing the needle valve was bad in one of your carbs. So many things can cause the problem you described in your original post and unfortunately not everyone shares what the ultimate fix turned out to be so others can learn from it.
I consider myself a pretty advanced mechanic, and I always learn something new on this forum |
|
Back to top |
|
|
|