ShopTalk Forums | Aircooled VW Tech & Restoration Help

Your foot on the floor and NO accelleration, coupled with the *POPS*
you hear tell of a LEAN condition.

I would check the main jets, since it runs well at slow speed(below 30-35)
and clean as necessary.

Yo uare NOT getting enough fuel to keep the bus at *speed*.

Continuing to run your bus lean will result in stretch/ddropped valves.

Since you feel you have enough fuel capability through the fuel system,
it is time to check the carb. A float that keeps sticking closed, will also
cause this.

Don

dstar wrote:Your foot on the floor and NO accelleration, coupled with the *POPS*
you hear tell of a LEAN condition.

I would check the main jets, since it runs well at slow speed(below 30-35)
and clean as necessary.

Yo uare NOT getting enough fuel to keep the bus at *speed*.

Continuing to run your bus lean will result in stretch/ddropped valves.

Since you feel you have enough fuel capability through the fuel system,
it is time to check the carb. A float that keeps sticking closed, will also
cause this.

Don

Hi Don,

As I understand it the richness of the mixture is determined by the carbs. As I am planning on swapping to Dells I am not going to take the solex's off and do anything to them. I am hoping the problem will be solved by swapping.

I appreciate the warning - but I am not planning on driving her anywhere until this is resolved.

I am also planning on going Pertronix (on a vacuum dissy) and a flamethrower coil. Would you do this before or after swapping the carbs?

Thanks
Marcel

Piledriver wrote:A $5 fuel pressure gauge will tell you a lot...

Found this -> http://minimopar.knizefamily.net/quickfpg.html
and this -> http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 94991&rd=1

Thought I might give it a go.

That pressure guage on ebay will be a waste of time. It only needs to show up to 10psi max, your fuel pressure will bairly register on that...

With reguard to swapping the points etc, do the carbs first, then do the points, always best to swap one thing at a time, because if you swap both, and it runs bad, you won't know if its the carbs or the ignition. You don't really need to add a flamethrower even, a bosch blue or even the stock coil will do fine..

Chris Percival wrote:That pressure guage on ebay will be a waste of time. It only needs to show up to 10psi max, your fuel pressure will bairly register on that...

Good point, read too fast, saw it as 10psi, not 10 bar. Doh!

Chris Percival wrote: With reguard to swapping the points etc, do the carbs first, then do the points, always best to swap one thing at a time, because if you swap both, and it runs bad, you won't know if its the carbs or the ignition. You don't really need to add a flamethrower even, a bosch blue or even the stock coil will do fine..

Right. I'll do it in that order. Will need to do another post then. I have an auto bus, I was advised I have to tap one of the manifolds for a vacuum line. So will need to find out how that gets done first. I'll hijack my own thread, any ideas anyone?

This has also been covered!

Do a search for "tap AND manifold AND auto"!


Make sure you check the box at the bottom left hand corner, to
show the results as POSTS...... lots easier to read!


Don

This probably has nothing to do with it as your carbs are popping, indicating badly adjusted valves or a lean condition...

... but if you hook the coil up backwards---that is reverse power and points--- you will have an absolute dog, might go 45 MPH. It will idle OK.

It's early for me, but IIRC "15" gets power, and "1" gets the points wire.

(Electrons like to flow from hot center of the plug... The motor will not take a load, the spark will "blow out" or just not jump under load)

dstar wrote:This has also been covered!

Do a search for "tap AND manifold AND auto"!


Make sure you check the box at the bottom left hand corner, to
show the results as POSTS...... lots easier to read!


Don

Hey Don,

Yep, found the posts - although reading all of that has made me slightly apprehensive of doing it. FidoDido was the one who told me I'd need to tap them in the first place. Will have to drop him a mail/pm to see how he got on.

Cheers
Marcel

Piledriver wrote:This probably has nothing to do with it as your carbs are popping, indicating badly adjusted valves or a lean condition...

... but if you hook the coil up backwards---that is reverse power and points--- you will have an absolute dog, might go 45 MPH. It will idle OK.

It's early for me, but IIRC "15" gets power, and "1" gets the points wire.

(Electrons like to flow from hot center of the plug... The motor will not take a load, the spark will "blow out" or just not jump under load)

Erm, Piledriver, don't mean to sound ignorant, but you lost me there mate. You may have noticed it takes a few, elaborate explanations to get things into my head.

Sorry, it's not ignorant... But it is something ALL mechanics need to learn sooner than later, preferably the easy way...

The spark wants to move from negative to positive, as all good electrons do.
(->>+)
Electrons leave a hot point easier than a cold one... nah, too much info...

Ground is (-)

If you hook the push on power and points connections to the coil up bassackwards, the center electrode in the plugs (that gets HOT) is then (+) and the spark will not jump anywhere as easy... It will dog when you step on it, but it will idle OK.

The coil (if you look close) has a 15 by one terminal, and a "1" by the other. Power/backup lights go to 15. Points go to 1.

Takes 3 seconds to check... easy to screw up, esp if you don't know.

Oh, and if you HAVE points, check them, if they are closing up you can get some of the symptoms you have.

The highest faiure rate item on any engine is the IGNITION.
ALWAYS make sure it's right first.
You can spin your wheels forever troubleshooting carbs/injection and it was the ignition all along. Been there/done this.

Thanks Piledriver, I will check that too.

Piledriver wrote: The coil (if you look close) has a 15 by one terminal, and a "1" by the other. Power/backup lights go to 15. Points go to 1.

Takes 3 seconds to check... easy to screw up, esp if you don't know.

Oh, and if you HAVE points, check them, if they are closing up you can get some of the symptoms you have.

The highest faiure rate item on any engine is the IGNITION.
ALWAYS make sure it's right first.
You can spin your wheels forever troubleshooting carbs/injection and it was the ignition all along. Been there/done this.

And the forums are back!
Piledriver, just wanted to say I checked and all was on the right way. Although now I know where to plug in my reverse lights when I add them.

I found the exhaust spits out this black watery stuff when the car is running. I took 1 of the plugs out and looked quite black (didn't take a pic). That usually means the engine is running rich? Any ideas on the crud coming out of my exhaust?

Soot.

You can get that in your exhaust (heavily) under 2 conditons:
Too rich
Too LEAN.

Too rich, it's obvious.

Too lean, you get a lot of misses, and the unbrunt gas ends up in the pipes.. and burns occasionally.

Soot.

You can get that in your exhaust (heavily) under 3 conditons:
Too rich
Too LEAN.
Poor ignition.

Too rich, it's obvious.

Too lean, you get a lot of misses, and the unbrunt gas ends up in the pipes.. and burns occasionally.
Poor ignition, same thing. Should have a nice fat blue spark at the plugs at any speed.

The water is a normal byproduct of combustion, you won't see it once the exhaust heats up.
(stays vapor vs condensing in cold pipes)

Thanks Piledriver. Another mystery solved.