It suddenly stopped sucking fuel, fixed.

[burn_your_money]

You mean in the lines just before the injectors?  Some injectors getting the fuel they needed but not all?  Hope it continues to start once it cools down over a cold night.  Keep us posted.

Yes, or even air in the pump only allowing some of the injectors to get some fuel some times.

[ORCoaster]

I agree.  Sometimes these pumps are harder to burp than a baby.  Like they store pockets of air for later or something.  We need clear plastic pumps.

[rabbitman]

We need clear plastic pumps.

haha that would be cool.

So today at 15F I tried to start it. I did a complete pre-glow til the relay clicked off and then glowed til the light went off. It cranked real fast, firing on all four and almost fast enough to pass the starter so I stopped to reglow it and then it would just do the "fire on one cylinder" thing and wouldn't even think of starting so I plugged it in...............I'll go try now..............

Fail, it was plugged in for 6 hours so I thought I'd glow 10 seconds (longer than the light calls for), leave the CS knob in and not push the go pedal. It started and quit so I glowed a bit more and pulled the cold start and push the go pedal but by then it was done.

[rabbitman]

OK, disregard most of that last post, the block heater cord is a poor connection to the block heater itself so the oil pan heater was the only thing working .......... it has been intermittant so just now I wriggled the plug and heard coolant start to sizzle. grrrrr

[rabbitman]

So a half hour of actually having a block heater going and the hoses and VC warm to the touch failed to start it, very little firing even.......a total joke........

I'll get my hands on a dial indicator and see what that's at. I don't see how it could be the problem since it runs soooo good but right now I'm out of ideas.

[ORCoaster]

The only time mine acts like that is when there is air in the pump or lines.  Can you see air anywhere when you are cranking it.  Return line might show it best. 

A real catch 22 here in that you need the air out to get it to start and the air is preventing that from happening.  Only solution I could recommend it a pump on the inlet or a squeeze bulb but that would be a royal pain in you cold weather.

[rabbitman]

The only time mine acts like that is when there is air in the pump or lines.  Can you see air anywhere when you are cranking it.  Return line might show it best. 

A real catch 22 here in that you need the air out to get it to start and the air is preventing that from happening.  Only solution I could recommend it a pump on the inlet or a squeeze bulb but that would be a royal pain in you cold weather.

I have one on my rabbit and haven't had an issue with it in the cold........granted, I rarely use it either though.

[rabbitman]

 

So today I plugged it in until the top rad hose was really warm to the touch and it still didn't want to start. Finally after cranking forever the rpm got high enough and it fired up and ran PERFECT. This thing runs like a dream........

Pulled it in the shop and checked compression, the results are depressing.
Checked almost up to full temp.
#1: 330psi
#2  250
#3  265
#4  160

Its gotta be the rings since I just redid the valves. The cylinder walls looked nice, crosshatch were still visible.

Any chance dumping kerosene in the cylinders and soaking it will fix anything? I really don't feel like doing rings right now.

[ORCoaster]

Do you think the rings are in there tight and not expanding?  Hence the solvent in hopes of breaking them free?  Kind of a two edged sword here.  They may come free but then they may really be loose and your compression would get worse. 

Being where you are kind of rules out thicker oil now doesn't it.  Could you get the pistons down in the cylinders and try some ATF?  That stuff has a lot of detergent in it.  Are you close to an oil change.  Someone on here mentioned that they run a quart of ATF for the last few hundred miles in there oil before changing it.  Perhaps that might help from the lower end.  But in all reality the tops are where the coke is at most times.

If you already have the head off then aren't you half way home on doing the repair?  Or are you stating the cross hatching in the cylinders from your memory when you did the valves?

Bummer, but a kerosene soak and ATF in oil combo might get some results.  Do let us know. 

[rabbitman]

Yup, the crosshatch is from memory. IIRC the PO also posted about the crosshatch of this engine too.

Yeah I read (maybe on this forum) about soaking rings in kerosene to free 'em up but it's been a while.

One reason I'm thinkin' they're stuck is 160 psi means a ring either broke or has something else wrong with it.

I'll try a leak down if I can find the fittings and see if it's rings or valves........

[rabbitman]

I'm gonna start another post about my low compression since the topic has changed

http://www.vwdiesel.net/forum/index.php?topic=30534.msg273732#new