Definitive answers? Re: Awful performance of my 85 VW Diesel

79 300sd · Post by **79 300sd** » Fri Dec 24, 2010 8:23 pm

I just got home from working a the shop for a while. Got the engine and trans out. Found a valve adjusting shim had been spit out. Probably from making contact with the piston when the rod cap came off.

I had an 81 dasher a few years back and it lost a rod cap too. It got a new used rod and a fresh head gasket and served me well till I sold it.

33mpg and not much power was all it would do even after all of the adjustments. Never checked compression, but I'm wondering if this motor was just long overdue for a rebuild.

I really can't afford head studs right now, and need to have the car up and running as quickly as possible. The 420SEL uses wayyyy too much premium unleaded to drive to work every day. The golf is converted to run on wvo and has kept me away from the gas stations for months at a time. I intend to turn the wastegate down and limit boost to just a few psi for now. I'm hoping the engine will make it a few weeks like this. After the head studs, head gasket, and top from a turbo pump I'll be ready to turn it up some.

I really didn't even intend to use the 1.5 for very long, but if I like it and the mileage is good it might just stay in there.

I think I'll start a thread to show what I'm up to......kinda feel like I'm hijacking yours.

the vegenator · Post by **the vegenator** » Fri Dec 24, 2010 10:03 pm

Ha! No worries, sir. This is everyone's forum. If you start a thread, I'd love to see pictures of your progress, especially when it comes to pump adjustment.

The 1.6 NA in my car was rebuilt less than a year before I bought it. Cylinders bored 20 over. New head and such. Otherwise I would be worried about it crapping out too.

Tyler - Internal engine work and pump timing/pressure adjustments have me shaking in my boots, which is ridiculous. I should probably start with getting the appropriate tools needed to find tdc - any suggestions on that?

82vdub - Adding a return line to the veg tank and deleting the loop is the next thing on my list. My other diesel vw had the same fuel loop setup but none of the same issues though, so I've never been too concerned with it. Those friggin air bubbles though! I'll do anything to get them the heck out of there. May as well do things the right way!

coke · Post by **coke** » Fri Dec 24, 2010 10:49 pm

To find TDC, its easiest to remove the #1 injector, and stick a coat hanger or a metal rod down the hole and rotate the engine to where you think TDC is and notice where the rod/what have you stops moving.

79 300sd · Post by **79 300sd** » Sat Dec 25, 2010 12:05 am

Started a new thread here with some pics. viewtopic.php?t=10493

Coke, you have me worried about even running the turbo before I get the studs. Budget is super tight right now and the extra money for the studs and new head gasket won't be available for two or three weeks. I really want to put the turbo on now, because I know I'll procrastinate and not do it after I put the car back on the road.

Mike, I never loop my veg return because of the potential for air problems. Sometimes it is easier to add a low pressure fuel pump back by the tank so the lines and filters are no longer under vacuum. I usually use the master E8012S from advance or auto zone for around $40 and they work great.

Oh, don't be scared to do the timing and pump pressure checks/adjustments. The instructions make it seem a lot harder than what it is. Of course you could hillbilly tune it.....I learned a lot in that 174 page thread.

Post by **Fatmobile** » Sat Dec 25, 2010 1:31 am

I almost always loop my vegy line.

Otherwise you are pushing 5 times as much fuel through the filter.

People who run a return to tank setup don't have a vacuum gauge on their fuel line.

If they did, they wouldn't run a return to tank setup.

the vegenator · Post by **the vegenator** » Sat Dec 25, 2010 3:46 am

79- I'm getting there slowly but surely. I'm not a born mechanic - in the past 6 years I've gone from changing oil to replacing the whole front end. And there's always so much more to learn... thank Santa for this forum! And one day I'll have to drink some coffee and try to take on that monster of a thread that Hagar started.

Fat- Yeah, the veg loop kind of seemed inconsequential to me. It worked on my other car, so why not this one?

Not quite understanding why five times as much fuel would get pushed through your veg filter... and are you saying that the IP would create more vacuum when pumping/returning from/to tank?

-mike

79 300sd · Post by **79 300sd** » Sat Dec 25, 2010 7:34 am

Oh no!! Am I going to have to put a vacuum gauge on my fuel line now..LOL. I do have a pressure gauge between the filter and ip on my f-450.

Never thought too much about checking the vacuum. Just figured that the oil was already plenty clean after being run through the centrifuge and that circulating through a filter was no big deal. Haven't had to change the veggie filter on this one for a couple of years now. Heated 18 gallon aluminum tank, HOH, FPHE, six port pollack, two fuel pumps (one for each fuel), coolant wrapped filters, and some electric heat just before the ip. Did I mention the the vanes were stuck on this ip when I got the car. It had sat a few years from the PO trying to do a water pump and timing belt and wouldn't run without an electric pump. They freed up a couple of weeks after I got it running, but I left the pumps there so the filters wouldn't be under vacuum.

I bet the vacuum readings are pretty bad, especially with an unheated tank. Never had a problem with the 79 300SD even with an unheated tank, but the 80 300SD drove me nuts for a while. The F450 is wanting some heat in the veggie tank and a looped return.

Guess I should get a couple of valves from omar, unless you guys know of a better deal.

vwkook · Post by **vwkook** » Sun Dec 26, 2010 12:01 am

Not sure, but I really think the OP's engine timing is off by a tooth somewhere.

Post by **Fatmobile** » Sun Dec 26, 2010 11:32 pm

the vegenator wrote:
Not quite understanding why five times as much fuel would get pushed through your veg filter... and are you saying that the IP would create more vacuum when pumping/returning from/to tank?

-mike

For every 5 cups of fuel that go through the pump,
4 go back to the tank.
Vacuum can be especially bad when switching to vegy,.. expect to drive farther before switching, it'll need to be warmer if you are going to pump it faster through te filter.

Also,.. if you are going to flush everything in the pump back to the vegy tank before shutdown,.. that's a waste.

I loop to the output of the filter so fuel doesn't have to be pulled through the filter at a faster rate than it's being used,..
also allows a filter backflush on shutdown,
all the flushings go backward through the filter;
vegy, then vegy diesel, then diesel if you flushed the pump good.

All that "thinner" fuel is stored in the filter, prepping the filter for an earlier switchover to vegy,
well it's not all in the filter but it will be the first stuff pulled from the vegy line when you switch to vegy.
Doesn't even need heated, it's vegy/diesel, all the diesel in the pump is also added to the loop making it even richer in diesel.

79 300sd it sounds like you have plenty of heat for down south.
In warm weather, with a looped setup,
I switch to vegy before I even start the car the next day.
There is so much diesel in the loop that by the time it warms up, I'm still not burning straight vegy.

79 300sd · Post by **79 300sd** » Mon Dec 27, 2010 10:15 pm

Do you have a diagram for your hose routing and valves? Any recommendations? I'm thinking about going ahead and looping my return.

Post by **Fatmobile** » Mon Dec 27, 2010 11:09 pm

I don't have a diagram or picture handy anymore.
Had a website but it's gone now,.. geocities shut down.
I have posted some info in the biofuels fora.

79 300sd · Post by **79 300sd** » Mon Dec 27, 2010 11:39 pm

Yeah....there used to be some good geocities sites.

I'll have a look around the biofuels forum or see if I can search through your old posts.

I don't mind putting in a little diesel every few thousand miles, but the looped return sure sounds like it could stretch that out.

mtran · Post by **mtran** » Wed Dec 29, 2010 5:07 pm

Try this:
http://www.burnveg.com/forum/viewtopic.php?t=28
http://biodiesel.infopop.cc/eve/forums/ ... 1441054682
Have fan.

79 300sd · Post by **79 300sd** » Wed Dec 29, 2010 8:42 pm

Thanks for the links. I remember reading the one by sunwizard a long time ago and already had it bookmarked.

I think I was having a blond moment about looping the return after the veggie filter. It all seems clear now. The back flush wasn't making sense before. When I do it I'll add a three port valve so I have the option to run on diesel with return to tank.

the vegenator · Post by **the vegenator** » Mon Jan 03, 2011 4:42 pm

Okay, I've meditated on it, dwelled on it, and researched it a fair bit... and I think I'm ready to take a deep breath and JUMP into the world of ENGINE/IP TIMING. It's okay that I'm not a specialist on this, right?

I'm fixin' to tackle multiple jobs at once (rather, in appropriate order)... my concern is, with the timing belt off, what other engine-related diagnostics and repairs could I also address? This is a slippery slope, and I'm only looking to disable this car for a week... but if there's anything I'm forgetting or any other maintenance I could address please shout it out!

The list so far:

- Verify & correct crank/cam tdc with flywheel (using notch on flywheel and wire probe down cylinder #1).
- Install new timing belt and tensioner
- Re-set IP timing
- Check lifter spacing and install shims where needed

If I'm already going this far, I'd also like to try and fix the oil leaks that have coated the back, front, and bottom of the engine in oil. The front crankshaft seal is an obvious candidate. But are the rear seals worth replacing if I have no other reason to pull the transmission?

Also curious about the cam baffle cover that some parts stores carry - it's advertised as a miracle cure-all for oil leakage through the valve cover gasket. As I've never had any luck sealing the valve cover thoroughly, I'd gladly spend a few extra bucks to try something new... any of y'all tried it?