TheSamba.com :: View topic

Wed Mar 10, 2010 5:58 am

I have a 74 standard beetle, 1600DP, 009, 34PICT-3. I've been driving it for about a year, with a variety of problems along the way.
The car starts easily enough, and runs fine until it warms up, but stalls easily and refuses to restart until the engine cools down. I, and four different mechanics, have been unable to find vacuum leaks.
When the engine is warm, it gets less power, and shudders a lot. The last mechanic said it was gunk in the fuel tank, but the fuel filter itself is clean, and the gas is clear - should I pull the gas tank out and seal it?
I'll be giving the car a tuneup, valve adjustment, and compression test this evening, based on some advice I got earlier.

Stray

Wed Mar 10, 2010 7:17 am

Maybe the fast idle cam is not working or is the choke not opening?

Wed Mar 10, 2010 8:04 am

Check the fuel pump rod. They run in a plastic guide and over time gunk builds up, the plastic can break and the rod gets tight. As the engine warms everything swell from thermal expansion and the rod stops running the full stroke. They've even been known to seize when hot starving the engine for fuel completely.

Dave

Wed Mar 10, 2010 8:05 am

Most probable here is Timming on the 009 Dizzy .
Sound's like she is runnin Hott due to badd or inccorrect Timming .
My guess is the Slash on the Dizzy rimm under the capp is turned wrong .
In addition to this your probably Timming off the Stock Crank Pulley Timming Mark .
V.W.'s time per the type Dizzy used .
Meaning the Dizzy the motor came with was Matched to the Crank Pulley .
So if your motor came with a Dizzy that timmed at 7.5 DEg. BTDC then they would use Crank Pulleys that have a TDC mark and a 7.5 DEg. BTDC Mark .
If you use this mark to time an 009 then your of 2.5 Degrees on your Timming .
009 Time at 10 Deg, BTDC at 28 too 32 Deg. total advance at 3400 R.P.M.
Use a Aluminum degree pulley of a stock Diameter .
Match the degree pulley up to your stock pulley by the TDC mark then make a 10 deg. mark and a 28 deg. mark and a 32 deg. mark .
Be Precise !
Slash mark on rim of the Dizzy need's to be turned to number 1 Plug wire < Per capp installed via the capp notch ?
Then time it 10 Deg. BTDC .
But the extreme heat you refer to ??
Perform this test >> twist Dizzy rotor approx 1/8th turn to one side and lett go .
Should spring back to it's original posistion !
If not get a new Dizzy .
Dont Pull Spark Plugg's on a Hot Motor . Stripp's Plug holes out etc.
Im not much on Compression Testing !
Conventional Compression testers also stripp out Plugg Hole's !
Bugg's are Infamous for spittin plugg's out runnin down the road .
I perform a Crankin by hand on a warmed up motor while observeing the Dizzy rotor per Cyl. Compression Test . You can feel it .
Theres to many Variables involved here to rely on conventional compression test as the final word .
Any question's post again !
Sean

Wed Mar 10, 2010 8:22 am

Thanks for the advice!

I have an SVDA dizzy on another engine, which is on my workbench waiting for the torque buddy, flywheel install tool, etc. Is there any reason not to remove the 009 entirely and try the SVDA?

I'll pull the fuel pump and make sure that the rod underneath isn't binding or otherwise in bad shape.

Stray

Wed Mar 10, 2010 9:49 am

Get the distributor swapped and tuned correctly. The next step I would do is check the fuel pressure after the fuel pump. This will clear up any fuel restriction myths. 2lbs is plenty. If after it warms up and you lose pressure, I would look into the tank. If not, I would guess you have a lean condition somewhere in the carburetor. Jetted too small or more likely junk in the carb restricting fuel flow.

Wed Mar 10, 2010 2:19 pm

djkeev wrote: Check the fuel pump rod. They run in a plastic guide and over time gunk builds up, the plastic can break and the rod gets tight. As the engine warms everything swell from thermal expansion and the rod stops running the full stroke. They've even been known to seize when hot starving the engine for fuel completely.

Dave

Rick Higgins talks about this in his Bug Me video. He recommends that, even if the plastic fuel pump pedestal isn't broken, this can happen if it fits too tightly in the case. Just sand the part of the pedestal that fits down into the case until it no longer is tight.

Wed Mar 10, 2010 4:24 pm

I removed the fuel pump. The rod that drives it doesn't appear bent or damaged, The bakelite-looking thing between the pump and the engine case came out with some resistance, but not that much - I had to pry it, but only gentle pressure with one hand in the tool, never enough that I thought I'd break it. I'll sand it, clean it up a little, and reinstall it.

I have to get some of the Bug Me videos, but my current VW budget is already well into the red from an unexpected transmission failure.

Stray

Wed Mar 10, 2010 5:28 pm

Clean the push rod, and also inside the plastic piece. The bore can build up with deposits that squeeze the rod.
Take a drill bit just a tad smaller than the rod and gently scrape the sides of the bore by twisting it in the bore by hand.
You will most likely come out with a small pile of black crud. Just don't break the plastic or get carried away and make the bore bigger.

Let us know
Dave

Wed Mar 10, 2010 5:37 pm

I cleaned it out with a rod and some rags, it wasn't all that bad. The rod fits inside, but not snugly - it can move a little, and goes in and out without scraping or binding. I sanded the outside lightly and reinstalled it, I'll see how it sounds in the morning and decide if I should be driving it to work.

The dizzy lets me turn it a little less than an 8th of a turn clockwise, and not much at all counterclockwise.

Stray

Wed Mar 10, 2010 5:38 pm

Stray Catalyst wrote: I cleaned it out with a rod and some rags, it wasn't all that bad. The rod fits inside, but not snugly - it can move a little, and goes in and out without scraping or binding. I sanded the outside lightly and reinstalled it, I'll see how it sounds in the morning and decide if I should be driving it to work.

The dizzy lets me turn it a little less than an 8th of a turn clockwise, and not much at all counterclockwise.

Stray

Hey, its a cheap and easy place to start!!!

Thu Mar 18, 2010 10:10 am

I have a similar problem with my 1970 1600 bug. Runs fine, but after about 30-40 minutes of running abut 50mph it starts shuddering (not sure if thats the right word. The motor starts to feel really unbalenced. like not all cylinders are fireing). Then it dies. After about 15 seconds it will start back up but I have to let it idle a while to get it running right again. goes about 20min and does it all over again. I swapped out the fuel pump. checked the pump push rod and it looks fine. I disarmed the choke too and still does it. fuel filter is clean. What do you think?

Thu Mar 18, 2010 10:32 am

vwluke wrote: I disarmed the choke too and still does it.

So when you "disarmed" the choke is the choke butterfly vertical (it should be, but you may need to pump the accelerator some to start).

If the choke is "disarmed but mostly horizontal, you'll start out OK but be runnin' rich once the engine warms up.

Did you pull out the choke heater element (which has the bi-metallic spring) or just pull off the choke heater wire to "disarm" it?

Thu Mar 18, 2010 10:36 am

Timing-Please make sure you are on the correct side of the block for timing. ex. +7.5 vs. -7.5

It will run be have some of the same symptoms your describing

Thu Mar 18, 2010 10:57 am

the butterfly is vertical. I turned the heating element so the butterfly was all the way open. (i think) The dashed line is closest to the front of the car. I just unhooked the wire and taped it off. Should i remove it completly? It definetly ran way better after disarming the choke, but it still shakes like hell, like i was saying above.

I dont think its a timing issue, cause i drove from PA to MO and it was fine all the way out and then about 10 miles away from my destination it started being shitty. And other than that it runs fine.

Thu Mar 18, 2010 11:59 am

I still think it is a vacuum leak on one side of the engine at the intake. Either at the head or the boots. It just sounds like it is imbalanced.

Thu Mar 18, 2010 12:01 pm

vwluke wrote: the butterfly is vertical. I turned the heating element so the butterfly was all the way open. (i think) The dashed line is closest to the front of the car. I just unhooked the wire and taped it off. Should i remove it completly? It definetly ran way better after disarming the choke, but it still shakes like hell, like i was saying above.

I dont think its a timing issue, cause i drove from PA to MO and it was fine all the way out and then about 10 miles away from my destination it started being shitty. And other than that it runs fine.

How is it under full load high rpm, like going up a real steep hill? Fuel starvation starts when you're demanding alot of fuel.

Thu Mar 18, 2010 2:04 pm

it only does it at high rpms like on the highway. it doesnt do it around town when its running at high rpms. The fuel filter didnt have much fuel in it after the times it left me on the side of the road. just driving around town it is full though. What would cause fuel starvation?

Thu Mar 18, 2010 6:25 pm

Your steel fuel line through the body, and/or the fuel tap inside the tank might be slightly blocked. The pump is then unable to pull enough gas and it eventually dies. Letting it sit allows fuel to seep through the gunk.

The fix for this is to remove the gas tank, and clean or replace the tap, along with the (probably missing or trashed) filter screen. Then you'll want to run carb cleaner through the steel fuel line through the chassis and let it sit overnight. Plug the lower end. You can even run a flex cable through to mechanically remove any crud.

Fri Mar 19, 2010 9:27 am

I've removed the fuel line from the carb, and when I turn the motor over, it pumps gas without hesitation. I don't have a fuel pressure gage, and I haven't seen what a "normal" flow would be, but it pumps in the kind of spurts I'd expect from that type of fuel pump. It looks like it may be my mexican carb - the choke seems to get stuck pretty easily. I'm buying a German 34PICT-3 carb from one of the vendors on this site, I'll clean it and rebuild it before I install it.

If the fuel tank is full of rust from ethanol-based fuels, would it help to clean and coat the inside of the tank? My FLAPS has some gunk that seems designed for the purpose, and is cheaper than a new tank.

Stray