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Wed Jun 22, 2016 6:11 pm

I got stuck on the side of the road today due to fuel starvation, caused by a stuck needle valve. I can manually cause it to stick by pushing the piston up into the valve, and pop it out w/canned air. Is there a way to fix these once they start sticking or are they junk at that point?

Or - could this be an issue of too low fuel pressure?

Thanks!

Victor

Wed Jun 22, 2016 6:48 pm

I guess teeing in a gauge would be the first step towards an answer.

Wed Jun 22, 2016 6:50 pm

Low fuel pressure shouldn't effect it like that, just the weight of the float should pull the needle valve down & open.

Wed Jun 22, 2016 6:53 pm

Old n' slow wrote: Low fuel pressure shouldn't effect it like that, just the weight of the float should pull the needle valve down & open.

I take that back, I was thinking about some other carburetters that have the needle valve wired on the float arm.....I believe Solex carb's are free floating needle valves??? Been awhile since I took mine apart.

Wed Jun 22, 2016 7:01 pm

The last new rebuild kit I used, I installed the "new" needle valve. MISTAKE.. It stuck open and flooded my engine.

I had a very old used needle valve, may be original in my carb parts. I checked it and it worked smoothly in/out w/out sticking. I've had no issues since installing this old valve.

Just another sad statement about the woeful quality of "new" parts sold today.

Wed Jun 22, 2016 11:21 pm

I wonder if something is stuck in the valve, like a tiny bit of rubber hose, or whatever.

Tim at Volkzbitz know which brand to get. Email him and ask.

Damn, Victor, you've been screwed lately.

Keep your chin up.

Tim

Thu Jun 23, 2016 3:15 am

Ah no worries. 2 failed aftermarket parts, one bit me because I forgot to renew it when I redid all of the other hoses. Driving it to work today too. :D

Thu Jun 23, 2016 6:30 pm

Happened again this evening. I swapped out the carb to one of the VolkzBitz-built ones and continued on my way.

I suppose the needle valve I took off of the spare [EDIT] carbs could also have been bad.... but now I'm concerned. Can a mechanical fuel pump be intermittently bad? can the Bakelite holding the rod expand more with age? it's [EDIT] older than I've owned the car (3.5+ years).

Thu Jun 23, 2016 8:47 pm

Are the days getting hotter there than in the past?

Checking out the flange is easy enough. Just remove the pump and then the rod (first, always, first), then remove the flange.

Let the flange fall back into the hole. If it slides in easily, it's okay--even on a cold engine.

Use new gaskets to re-install everything.

By the way, I think Tim at Volkzbitz uses a rebuild kit from Wagner. I may be wrong, however. And I don't know if the kit comes with a new needle valve, for that matter. Maybe you can shoot him an email and ask him.

Tim

Fri Jun 24, 2016 6:41 am

I've had the parting line gasket cut poorly and the float would hang up on the excess gasket- first bump I hit pulling over to the side of the road freed it up- can imagine how many possibilities there were for that before I found the poorly cut gasket- just trimmed it close on both sided.

Fri Jun 24, 2016 6:49 am

take out needle,lay extra fine scotchbite on bench,draw sides of needle across scotchbrite to polish it till it slides in the bore.

Fri Jun 24, 2016 7:12 am

Thanks, I will give it a go.

Fri Jun 24, 2016 3:18 pm

Happened again with the VolkzBitz carb, although I was able to keep it running after stumbling for a minute.

I'm pretty sure at this point it has to be an issue with the fuel pump rod and the bakelite piece. Johnnypan - would u agree?

Fri Jun 24, 2016 3:56 pm

It could be the rod sticking in the flange after it gets warm. Easy enough to check.

I'm thinking you may have a problem with the pump, though.

Check both.

Tim

Fri Jun 24, 2016 3:56 pm

If the rod and flange are original to your car and never gave you an issue, I doubt they are causing the problem now, they've been pumping away for years without issue why would they suddenly start?

Personally, I have had to pry more than a few flanges out of cases and the pumps worked fine. And prying an old flange out of the case risks breaking it as they love to stick after being in the engine for years and become brittle. If you really want to check it, get the engine hot and just lift up the pump and see how easy the rods slides

Check your fuel pressure as mentioned above and go from there.

brad

Fri Jun 24, 2016 4:34 pm

Thanks all for your input. I will pick up the troubleshooting bright and early tomorrow a.m.

This I not the original pump. It's probably about 2.5 years old. I don't recall if I replaced the pushrod, definitely left the bakelite guide in its place. The factory engine had an AE code this one has an AK engine code which I think is a replacement engine. [EDIT] I have no idea if the bakelite piece is original to the engine.

Fri Jun 24, 2016 5:09 pm

I had this issue, the needle valve was sticking half open. So it allowed fuel to get into the bowl, but not fast enough if I ran above 45mph. It was a pain to find that culprit! New needle valve fixed it. It's been about 8 months now with no issues, until the other day she acted the same as soon as I tried to leave somewhere with the engine warm. Although it happened twice that week, it hasnt happened again, so I have no idea what this new issue is on my end.

Fri Jun 24, 2016 5:53 pm

I thought it was that the 1st time. Then it happened the next day w/the replacement needle valve. Then again today w/a German Solex 34 PICT-4 rebuilt for me by possibly the most skilled carb restorer on the site...each time after the car had been sitting for about 20 minutes after a 20+mile drive in 85*+ weather....it ain't the needle valve.

Fri Jun 24, 2016 7:04 pm

It's times like this I temporarily install an electric rotary pump in line bypassing the mechanical and drive it for a few days to see if the issue still occurs.
Avoid the noisy clicker pumps unless you have a good fuel pressure regulator to tame it down to a manageble pressure.

Fri Jun 24, 2016 7:48 pm

Each time it happened while you were driving? Like the car was actually in motion and then just seemed like it stopped getting fuel and slowed and stalled?