Mileage and voltage regulator

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whc03grady
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Mileage and voltage regulator

Post by whc03grady » Fri Apr 10, 2009 2:40 pm

Gertie gets not so great mileage (odometer doesn't work, so I don't have a figure). A full tune-up is in the works, rest assured.

In the meantime, I've read where a bad (re: non-Bosch) voltage regulator can contribute to poor mileage and lo and behold, Gertie's is some cheapo. I called the local import place for some prices on various things and asked him about VRs. He says (1) the voltage regulator only has to do with charge to the battery and wouldn't cause or contribute to poor mileage; (2) they don't make 'em in that bread-loaf style anymore. I thought (1) sounded suspect, given how finicky these fuelies are about their electricals.

So, can cheap or bad VRs lead to poor mileage?
Ludwig--1974 Westfalia, 2.0L (GD035193), Solex 34PDSIT-2/3 carburetors.
Gertie--1971 Squareback, 1600cc with Bosch D-Jetronic fuel injection from a '72 (E brain).
Read about their adventures:
http://www.ludwigandgertie.blogspot.com

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Hippie
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Post by Hippie » Fri Apr 10, 2009 5:46 pm

They must've stopped making the breadloaf style in the last few years then. I bought a new Bosch in that style...maybe 2005
What's the part number?
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tristessa
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Post by tristessa » Fri Apr 10, 2009 6:01 pm

(1) from the local import place tells us the guy has no idea how D-jetronic works. A failing VR can certainly do it .. a cheap one maybe, if it's not functioning properly. When the regulator starts to fail, voltage in the electrical system starts to drop. Lower voltage does "wonky" things with the FI, causing it to run rich .. which certainly has an effect on fuel mileage.

I'd seen something about the breadloaf VR not being made anymore, but I haven't heard anything good or bad about the solid-state ones available. If you can find a new old-style regulator I'd go that route, otherwise get the new-style one and cross your fingers. Maybe look into an alternator conversion; the DDB has a bolt-in kit available .. or PM me.
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Amskeptic
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Post by Amskeptic » Sat Apr 11, 2009 6:03 am

tristessa wrote:(1) from the local import place tells us the guy has no idea how D-jetronic works. A failing VR can certainly do it .. a cheap one maybe, if it's not functioning properly. When the regulator starts to fail, voltage in the electrical system starts to drop. Lower voltage does "wonky" things with the FI, causing it to run rich .. which certainly has an effect on fuel mileage.
I'd seen something about the breadloaf VR not being made anymore, but I haven't heard anything good or bad about the solid-state ones available. If you can find a new old-style regulator I'd go that route, otherwise get the new-style one and cross your fingers. Maybe look into an alternator conversion; the DDB has a bolt-in kit available .. or PM me.
Horsefeathers. That car looks like it is getting horrible gas mileage just looking at the soot all over the back of the car. If voltage is so low that the D-Jet is suffering, I assure you the car would not be starting in the morning. I say, I say you have a vacuum leak at injector seals or manifold sensor hose, or somewhere. . . D-Jet goes horribly rich with vacuum leaks, unlike L-Jet.
Colin
BobD - 1978 Bus . . . . . . . . . . . 112,660 miles
Chloe - 1970 bus . . . . . . . . . . . 206,845 miles
Naranja - 1977 Westfalia . . . . . 112,885 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,899 miles

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tristessa
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Post by tristessa » Sat Apr 11, 2009 10:43 pm

Amskeptic wrote:Horsefeathers. That car looks like it is getting horrible gas mileage just looking at the soot all over the back of the car. If voltage is so low that the D-Jet is suffering, I assure you the car would not be starting in the morning. I say, I say you have a vacuum leak at injector seals or manifold sensor hose, or somewhere. . . D-Jet goes horribly rich with vacuum leaks, unlike L-Jet.
Yes, the car is obviously running rich; yes, running rich gives bad mileage. It's quite probably something vacuum related, such as the hose to the MPS or the injector seals. But the question was about the voltage regulator, and whether it has an effect on mileage and mixture, so I answered that.

The voltage regulator and system voltage does get D-jet wonky, and does cause rich-running and poor mileage; I don't care what the manuals say. Hundreds, probably thousands of these cars have had aftermarket carbs installed to "fix" a "fuel injection" "problem" that was just a failing voltage regulator. Horsefeathers? It's referenced as far back as 1996 on the vwtype3.org mailing list archives, and I've Been There And Done That so many times (at least a dozen) in the two years I worked at the DDB shop that it isn't even funny.

New hoses connected securely, new injector seals, proper fuel pressure, timing and valve adjustments spot-on, un-tampered MPS, all green-lights on the VW 1216 FI diagnostic machine .. yet still pig-rich with crap mileage, and 11.9-12.3V system voltage. Swap the regulator for new Bosch, system voltage goes up to 14.1V and the problem goes away. After the second time doing all that and fixing the problem with a new regulator, I started to check the voltage *first*. :lol:
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Amskeptic
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Post by Amskeptic » Thu Apr 16, 2009 4:30 pm

tristessa wrote:
Amskeptic wrote:Horsefeathers. That car looks like it is getting horrible gas mileage just looking at the soot all over the back of the car. If voltage is so low that the D-Jet is suffering, I assure you the car would not be starting in the morning. I say, I say you have a vacuum leak at injector seals or manifold sensor hose, or somewhere. . . D-Jet goes horribly rich with vacuum leaks, unlike L-Jet.
Yes, the car is obviously running rich; yes, running rich gives bad mileage. It's quite probably something vacuum related, such as the hose to the MPS or the injector seals. But the question was about the voltage regulator, and whether it has an effect on mileage and mixture, so I answered that.

The voltage regulator and system voltage does get D-jet wonky, and does cause rich-running and poor mileage; I don't care what the manuals say. Hundreds, probably thousands of these cars have had aftermarket carbs installed to "fix" a "fuel injection" "problem" that was just a failing voltage regulator. Horsefeathers? It's referenced as far back as 1996 on the vwtype3.org mailing list archives, and I've Been There And Done That so many times (at least a dozen) in the two years I worked at the DDB shop that it isn't even funny.

New hoses connected securely, new injector seals, proper fuel pressure, timing and valve adjustments spot-on, un-tampered MPS, all green-lights on the VW 1216 FI diagnostic machine .. yet still pig-rich with crap mileage, and 11.9-12.3V system voltage. Swap the regulator for new Bosch, system voltage goes up to 14.1V and the problem goes away. After the second time doing all that and fixing the problem with a new regulator, I started to check the voltage *first*. :lol:
Well, around these parts, you have to punch through my ignorant certitude. pleeze gimmee mailing list link to article so I can educamake myself and start expounding about the voltage regulator as though I was the one who discovered that problem.
:joker:
BobD - 1978 Bus . . . . . . . . . . . 112,660 miles
Chloe - 1970 bus . . . . . . . . . . . 206,845 miles
Naranja - 1977 Westfalia . . . . . 112,885 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,899 miles

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