running thicker fuel advances timing?

[vanbcguy]

another thing, my car has more power with the cold start lever pushed in. you would think it to be the other way around right?

That actually really means there's something goofy in your pump.  The cold start just gives a little 2 degree nudge to the timing piston - as soon as the pump is spinning much faster than idle its own internal pressure should be pushing the timing piston a lot further than 2 degrees.  If you're noticing higher RPM differences between the cold start in and cold start out then you probably have next to no internal pump pressure.  Your higher viscosity fuel would definitely help build more pressure in your pump giving you more dynamic advance, but adjusting the pump internal pressure (and fixing whatever is causing your low pressure) would probably REALLY surprise you...

[8v-of-fury]

when i got my '81 a few weeks ago, It had 1/4 tank of 4 year old diesel. So i pulled the fuel lines and hooked it up to a 4 liter jug of 2 liters 15w-40 diesel oil, 1 liter 2 stroke oil (ashless), and 1 liter of good 'ol ATF. I have driven it on normal diesel since and i think the seat of the pants experience was more on the "special fuel" lol. However i could be having the same problems as RoR.. The car has 410k kms and i have no idea of pump condition.

As stated though that combination of fuels probably yields another what 5-15,000 BTU's ??

Is it really cheaper to buy all those things? or do you just have MASS AMOUNTS of the stuff lying around? lmao

[745 turbogreasel]

I've noticed quieter idle, and a 1-2 MPH gain on a 50 MPH grade burning heated Vegoil, and attributed it to timing, but like the OP, took no pump measurement.

[dennis]

DUDE, RABBITONROIDS! you just have to give us a formula for this stuff you are running iot has been said more than once on this forum already, that your fuel gives wicked gnarly power and has excellent lubrication.  So how bout' it??? let us in on your little secret.  Or better yet patent the formula and sell it to racers etc. for a mint you always talk about how you don't have money well here is your chance at something incredibe.  Hell, I know that I'd buy the stuff from ya.

i dont know my exact formula tho. and who is gonna buy racing diesel? like 20 people on the face of the planet? im sure this stuff isnt safe for anything besides a VW diesel.

I do the same thing with waiste products. I have never had a TD other than a Mercedes Wagon. Sometimes I feel it helps over pump fuel, and other times not so good. I keep all my stale gasoline and mix that in too. I have even burned waist aviation engine, and transmission oils, which is thin enough to go 100% in the summer. Bottom line is if you filter it enough and it burns why not use it. In the past I have always based my mix on milege vs performance though.

[Rabbit on Roids]

I've noticed quieter idle, and a 1-2 MPH gain on a 50 MPH grade burning heated Vegoil, and attributed it to timing, but like the OP, took no pump measurement.

i will NEVER!ever run vegi oil in my diesel. not even if its set up right. ive heard too many horror stories about people coking their engines to death. diesels dont like to overdose either.

[Rabbit on Roids]

another thing, my car has more power with the cold start lever pushed in. you would think it to be the other way around right?

That actually really means there's something goofy in your pump.  The cold start just gives a little 2 degree nudge to the timing piston - as soon as the pump is spinning much faster than idle its own internal pressure should be pushing the timing piston a lot further than 2 degrees.  If you're noticing higher RPM differences between the cold start in and cold start out then you probably have next to no internal pump pressure.  Your higher viscosity fuel would definitely help build more pressure in your pump giving you more dynamic advance, but adjusting the pump internal pressure (and fixing whatever is causing your low pressure) would probably REALLY surprise you...

well, i did have to put a different body on the pump, i forgot about that. and when i did it, i never messed with the pressure regulator and i never swapped in the one from my TD pump, witch i still have. would it be worth while to install the old one? or should i just dive in head first and finally figure out how to tune my pump? ive never done anything besides set the idle screw, and max out the fuel screw. never even messed with the LDA cause i like how it feels like a hit when you get to 10 psi and it kicks in. my pump is probably more out of adjustment than any of you have ever seen. i knew nothing about fuel pumps when i built this one, just how to take them apart and put them back together and still have them work.

and as for the CS lever, im not for positive if it has more power throughout the power band, but i know it has a little more low end with the knob pushed in. i base that finding on the ability to burn out with the knob in or out. i can squeal 2nd with the knob out, but with the knob in, it fries the tires off again in 2nd, and squeals 3rd. maybe its just me tho. and it is quite possible that my pimp has no internal pressure. but it does leak like a bastard, so that tells me there must be some sort of pressure in there.

[rabbitman]

When I put new bushings in my IP I used all the old pump guts but I also used a different body. That screwed my internal pressure up bad! It's supposed to be like 43psi at 2000rpm (crank) but mine was at about 55psi @ idle .

I didn't know it was that bad for a few weeks but I did notice it had to crank way too much before it started, then once it started and the internal pressure came up it would clatter real bad so I put lots of washers under the timing piston to try and quite it down some.

Anyways I think you should at least check your pressure, as long as it leaks adjusting it won't really cut it, since you'll rev it high and the pressure will make it leak faster thus not advancing enough.

[Smokey Eddy]

When I put new bushings in my IP I used all the old pump guts but I also used a different body. That screwed my internal pressure up bad! It's supposed to be like 43psi at 2000rpm (crank) but mine was at about 55psi @ idle .

I didn't know it was that bad for a few weeks but I did notice it had to crank way too much before it started, then once it started and the internal pressure came up it would clatter real bad so I put lots of washers under the timing piston to try and quite it down some.

Anyways I think you should at least check your pressure, as long as it leaks adjusting it won't really cut it, since you'll rev it high and the pressure will make it leak faster thus not advancing enough.

What causes low internal pump pressure? I think i have this issue as well.
What are you saying about the loud clatter and adding washers to something?
Mine sometimes sounds like loose alluminum pans or like sheet metal is loose banging around in there but i just attributed that to 1 stage injectors...

[NintendoKD]

I thought I had bad bearings..... well they were bad, but I heard the same sound as the other guy like pans clattering, or maybe a monkey wrench banging around inside of my engine.  Time for a pump and injector rebuild I suppose, on top of having to rebuild the engine.

[Rabbit on Roids]

well, that crappy n/a pump isnt gonna do what you want it to bolted onto a fire breathing monster. thats like bolting on a rochester 1 bbl to a blown alcohol burning big block race engine. its not the best match. of course it will run, but not to its full potential.

[vanbcguy]

I thought there was a FAQ post about internal pressure, but it might have been on the other side.  Either way, here's the gist of it:

On the sprocket end of the pump there's a pressure regulator.  It's round with two flat sides and a depression in the center.  The center is the "adjustment" - if you press it down somehow (there's a Bosch tool for this, or you can use a hammer and a punch) you increase the pressure.  To reduce the pressure you have to remove the regulator from the pump and press it back the other way.  It's INCREDIBLY sensitive - it's not something you should adjust without some way of measuring the result.  We're talking fractions of a mm making big jumps in pressure.

There's two parts to the pressure regulation system - the regulator itself and the OUT bolt on the fuel return side of the pump.  It's got a small orifice in it and between the regulator and the out bolt the pressure inside the pump increases as RPM increases, pushing on the timing piston and advancing the timing.  If you don't have a proper OUT bolt (say you just stuck any old banjo bolt in there) then you have no restriction on the outlet side of your pump and next to no internal pressure.  The car will run but there will be next to no advance.

To check the pressure you need to measure what's going on inside the pump.  This is kinda tricky since there aren't really any provisions for it from the factory.  Some people drill a hole in the end of their OUT bolt and tap it for a gauge, the best method I've seen is using the little "pedestal" thingy on top of NA pumps.  It's large enough to drill/tap, comes off the pump and then you've got a nice reusable measuring "instrument".  The important thing though is that the OUT bolt still has to be in place and you have to be measuring on the PUMP side of the OUT bolt.

BTW, the NA pump can shoot out just as much fuel as the TD pump can... It's big difference is it can't HOLD OFF fueling until the turbo spins up like a TD pump, so you're going to leave great big smoke clouds... If you want to think about it like carbs, the TD is more like a vacuum secondary carb while the NA pump is more like a double pumper.  Both can deliver the same amount of fuel, the TD pump just lets you hold it off for a bit to prevent overfueling.

[rodpaslow]

I'll tell yeah, anything that improves power on my 1.6na I'd definitely take!

[Smokey Eddy]

I'll tell yeah, anything that improves power on my 1.6na I'd definitely take!

snail? nos?

[rabbitman]

For your reading pleasure http://www.vwdieselparts.com/forum/viewtopic.php?t=5936

[Rabbit on Roids]

wow, kinda makes me hopeful. i thought my car went alright already. its for sure the fastest diesel in town, hands down. and its the only diesel car in town.

so when i take and crank up the internal pressure in my pump to where its supposed to be, i should have wuite a bit more power, and probably a few more pounds of boost right? this would probably explain why it seems like my car has more power on some days than others.