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The 38 DGEV I installed a few months back really woke up my engine. The car runs stronger all the way up the RPM range, and starts better when cold then the 32/36 I had before. However, it can be a pain to restart when hot. It has even vapor locked on me while in traffic. I have since insulated the fuel line under the hood completely, which seemed to stop the vapor lock, but not the hard start. Now I'm wondering if the fuel is percolating in the bowl? Another difference I have with this carb was that I had to add a fuel pressure regulator, where as the 32/36 didn't need it. Any ideas?
James (the Hurricane Watcher)
 

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I had the same problem with my 38DGAS until I followed RallyBob's advice and moved the fuel inlet to the outboard port on the carb.

Remove the top of the carb and pull out the pressed in fuel line fitting. Drill out and tap the hole for a 1/8 NPT plug. Next, drill out and tap the blocked off outboard port and install a 1/8 NPT x 1/4 fuel line fitting. This mod will reroute the fuel line away from the hot exhaust mainfold and make a huge difference.

Keeping the carb heat shield in place will also be a big help.
 

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Gary,
I also swapped the fuel inlet like you did. But, you may have hit on something......what heat shield???
 

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Don't have a picture handy, but the 1.9's came with a thin metal heatshield that goes between the spacers at the carb base. It helps to deflect and dissapate the heat from the exhaust manifold. Opinions vary, but I am in favor of using it as it really helped with my vapor lock problem.

<Hoping you are not in the N.O. flood zone>
 

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It's Friday night.
Time to revive a old thread.

First lets look at the check valves in the mechanical pump.
There's two of them...


Now lets move to the pressure side.
This one should keep pressure (~3 psi) on the supply line.
The bowl full and the needle & seat working properly.

The problem will happen when the fuel boils and the float is heavier than the underlying puddle.

:)

I'm a bottom feeder kind of guy.


Have fun and enjoy your Opel/Opel’s.
 

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Had the same issue as you. Rerouted the fuel line to the starter side and then along the rad hose and in the stock inlet. No I don't have a heat shield. Adds more possible vacuum leaks. Not that hot up here in Canada. It boiled on a trip to Lk Tahoe. Everything is good now. I found the electric pump really helped for quick starts too.
 

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A switch for the electric fuel pump also allows one to shut down the pump approx 30 seconds before shutting the engine off, thus draining down the fuel bowl.

The radiator shroud fulfills an important function by directing air flow over, and around, the carb. Again, reducing the percolation factor.
 

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Opel Carburetor Heatshield and Insulators

OPGTS reproduction heat shield Part 9073 for $35.00.

http://www.ebay.com/itm/WEBER-38-38-DGAS-Carburetor-Spacer-5-5mm-fits-38DGAS-38DGS-38DGES-/271452016379?pt=Motors_Car_Truck_Parts_Accessories&hash=item3f33cd0efb&vxp=mtr
$18.95 Redline 99900 624
WEBER 38/38 DGS DGES DGAS DGMS Carb 6mm Insulator Spacer Gasket Block

1973 Ford Pinto Carburetor Mounting Gasket - Fel-Pro 60144 | StockWiseAuto
Fel-Pro 60144 or Victor G26726. Might have to trim gasket to fit Weber 38/38.
 

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I also run the 38, and they do dump more gas than the 32/36, lots of fun, and on a hot start I don't touch the gas pedal at first, helps burn out any left over gas, and I don't run the heat shield either. I have eliminated the stock fuel pump for elec. fuel pump. I think the elec. is a help, it eliminates an extra heat source, ( car parked, or sitting in traffic , heat transfer from block to stock pump, & lines), also with restart. Use a good HD fuel line, not just plain rubber, need some that is insulated, thicker,. My fuel line runs the stock route, and yes the fan shroud is a big part to keep the carb, & fuel lines cool. Might want to look into the OGTS starter, helps very much, no sluggish turn over any more when hot, that baby makes her jump.
 

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I talked with a guy at Redline Weber recently. He's been around for decades and confirmed what I've been suspicious of for some time. The boiling fuel problem is directly related to the percent of ethanol in the fuel. The more ethanol, the lower the boiling point. He told me something rather interesting. Even though the gas pumps in my area of the country (upstate NY) say 10% ethanol, they have been running 15% for years. Something to do with winter versus summer fuel and problems transitioning. The west coast is still on 10% as is much of the country. Al the things we've been doing to help this situation is an attempt to cure a problem brought on by ethanol. BTW the ethanol additives won't help this, they are designed to keep separation from occurring (a different problem). If things keep moving in the direction of increased ethanol percentages, we may have to all move to fuel injection. Fun, fun, fun!
 

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I talked with a guy at Redline Weber recently. He's been around for decades and confirmed what I've been suspicious of for some time. The boiling fuel problem is directly related to the percent of ethanol in the fuel. The more ethanol, the lower the boiling point. He told me something rather interesting. Even though the gas pumps in my area of the country (upstate NY) say 10% ethanol, they have been running 15% for years. Something to do with winter versus summer fuel and problems transitioning. The west coast is still on 10% as is much of the country. Al the things we've been doing to help this situation is an attempt to cure a problem brought on by ethanol. BTW the ethanol additives won't help this, they are designed to keep separation from occurring (a different problem). If things keep moving in the direction of increased ethanol percentages, we may have to all move to fuel injection. Fun, fun, fun!

Yep back in the early '80's while working at a Cry-sler dealership.
We ran into this problem. E-10 fuel that is.
The 2.2L with there heat stove type intake/exhaust joined together was part of the issue.
I made very good money putting electric fuel pumps into the K cars.
 

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Yep back in the early '80's while working at a Cry-sler dealership.
We ran into this problem. E-10 fuel that is.
The 2.2L with there heat stove type intake/exhaust joined together was part of the issue.
I made very good money putting electric fuel pumps into the K cars.
This holds true for the 1.9L that Opel used, another big help is to go to the sprint or header manifold to reduce heat transfer to the carb.
 

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I talked with a guy at Redline Weber recently. He's been around for decades and confirmed... BTW the ethanol additives won't help this, they are designed to keep separation from occurring (a different problem).
I've heard that a cap full of acetone is a good binding agent.
 
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