No hot start (IDI)

[belchfire]

Well I managed to get a couple of trouble free weeks out of it before the next problem started. When It's cold, It starts as good as a cold diesel might be expected to. If I go to the store about 10 miles and shut it down then I'm stuck. I can go to the post office (4 miles) and it will fire back up. I can go to work and it will fire up to go home.  I'm not switching to the SVO yet so we'll pretend that it's a straight diesel. I have a heater on the fuel filter and heaters on the injector lines. I installed an electric fuel pump between the filter and the IP. This system has been working fairly well for the past year.
I had the pump rebuilt last year to the tune of $600. Something bad happened at red line last summer and I think that a couple of the piston skirts got bent so it rattles and the compression is 400-325-350-425.
I've re-done the injectors. 1 was leaking between the halves and 1 was out of spec. The idle is erratic. Doing fine when cold but going way up when hot-sometimes. I know things sound bad (and I am putting in new pistons this winter) but it shouldn't start when cold either. If I have the block heater going for a couple of hours in the morning (fuel cold) it fires right up and runs great. I'm thinking that it's a viscosity issue. And maybe, more correctly, a charge pump issue. Or the delivery line check valves? There may have been some cavitation just before the filters clogged up so that may have helped. Rabbitman's got something on IP pressure. Where do I check that?

[Patrick]

I think you have a glow plug issue. Something to do with the sensor that's telling the glow plugs to turn on... Get a lead with alligator clips on both ends. next time it won't start, hotwire the glow plugs off the battery for 10 or 15 seconds and see if it will start. id engines need the heat... 

[81 vw pu]

Had a similar issue with a IDI ford a few years ago. If I poured cold water on the injection pump it would fire up again.
Are filter and line heaters on when running diesel? If so, then try no heat and see if it starts hot.

[belchfire]

Glow plugs are great. I did the individual wires some time ago so I could test them separately and they're fine. As for the sensor, it works the other way if anything, coming on even when it's warm. Regardless, if it was the plugs, then cold starting would be impossible too.
   I'll try the cold water trick. There's just the 1 heater at the filter which doesn't boost it that much. The ones on the lines are after so don't affect the incoming fuel. The bigger question is; if the cold water trick works, then why?

[mtrans]

If I poured cold water on the injection pump it would fire up again.

Do you drive same IP now or fix?
belchfire
I`ll change all 3 lines to clear ones.

[81 vw pu]

   I'll try the cold water trick. There's just the 1 heater at the filter which doesn't boost it that much. The ones on the lines are after so don't affect the incoming fuel. The bigger question is; if the cold water trick works, then why?

Well sounds like I'm barking up the wrong tree As my F-350 had a heated tank. HOH lines and a FPHE right before the pump.
WVO temp was 160-180f going into my pump. My theory was ( on my F-350) hot fuel + a high milage pump created too much internal clearance within the pump somewhere.
Dose'nt seem to be the same since you have low heat at filter and recent pump rebuild.

Do you drive same IP now or fix?

I replaced the pump with a used one.

[damac]

I was having an issue some months back with hot starting and a slight delay.   For me I redid the wiring and added an extra ground from the top starter bolt to the battery.

Are you sure your starter is turning things over just as fast as normal or are we talking full speed turnover and not even a sign of catching?

I also had that heat soak thing happen on my old f250 with a bad rebuilt pump.  Haven't experienced the same thing on the vw.

On my truck with that bad pump it would be ok cold and then take a bit longer but start on a real short stop and restart.  The heat soak sets in as the heat transfers with the hood down like say 20 minutes later after shutdown and the truck would just spin over without a sign of life.

[burn_your_money]

Do a voltage drop test on the starting circuit. I had the exact same problem and it turned out to be a few bad connections and wires. "They look good" isn't good enough.  Neither is a resistance test.

If dumping cold water on the pump gets to to start you likely need a new pump head.

[belchfire]

Cranking speed is acceptable. I have a Bosch rebuilt starter and the batt cables go directly to it. Just for fun, I put the charger on 200 amp boost which cranked it somewhat faster and it eventually fired. I'm theorizing that the faster charge pump speed overcame enough of the leakage to supply the main pump. Could it be a sticking pressure relief valve? Looks like a complete teardown to fix it. The SVO temp is fairly hot when I'm running that but I have no problem with that system. I'm wondering how much of this is related to WVO. I have a clean source of non-hydrogenated oil, heat it to remove any water and filter it through a 10 micron sock. Does processing it into bio-diesel solve gumming problems? I'm not sure it's worth the trouble.
    This has been another experiment in alternative fuel vehicles starting with alcohol in the '80s. 90 mpg (effective) without a loss of power is great, but doesn't produce any financial gain when I have to rebuild everything every 6 months. I was hoping to perfect the system so I could put a mercedes 300 td in my truck. Seriously reconsidering gas.
I'm on vacation for the next week so there will be an obvious break. I'll tackle the issue upon return. Feel free to comment.

[R.O.R-2.0]

i would filter it lower than 10 microns..

im gonna bet that what tyler said is accurate. sounds like your pump head is shot.

[81 vw pu]

Does processing it into bio-diesel solve gumming problems? I'm not sure it's worth the trouble. 

I did the wvo thing for about a year and then switched over to making bio-diesel. I still get a little glycerin fallout in my filters, but have had fewer problems.
And yes its a time consumning pain in the a$$ to make bio-diesel, but only cost me about $1.25 a gallon to make vs $4.00 for diesel.

[ORCoaster]

Time is still money.  Running around town picking up 5 gallon jugs or pumping it out of their waste bin into something of your own all should be factored in there.  Then the mess around the house, the smell on a hot sunny day like that waste bin area you get it from.  Phew.  Been through it all with my son and not willing to go back now that I own a diesel of my own. 

He still does the collect and filter thing at his place and says he spends the whole weekend working up 100 gallons at a time.  Being he is a high paid engineer his time is probably worth 25 bucks an hour and at 20 hours of time that exceeds the cost from the pump.  But if your time is cheap then have a day.  I can't afford the time with all the other projects I have going so I just pay the man at the pump and try to get the best MPG I can. 

[burn_your_money]

Cranking speed is acceptable.

It doesn't cost anything to actually check if there is a voltage problem although the charger does likely rule out that problem.

I would just manually power the glowplugs for a few seconds and you should be on your way. Easiest way is to just unplug the temp sensor and leave it unplugged. You'll quickly get a feel for how long to leave them on for.

It's probably a worn pump head if it is a problem with the pump and the only cure is a replacement. The other possibility is the starting fuel is inadequate. You would need to have the pump tested at a shop. For what it's worth a replacement pump would probably be easier.

[belchfire]

I get my oil once a week on my way home from work. Heating & filtering (cost of bags) isn't that much. The time spent pouring it into containers & filtering it could be better spent in front of the TV with a cold one, but you gotta do what you gotta do. I figure (minus the rebuilds) that it runs about $0.25/ gal. However if I have to do a $600 every year, then I might side with the to hell with it crowd. I thought that the Bosch pumps were suppose to be tough enough to handle veg oil while some others weren't. Once again, if the glow plugs were bad then cold starting would suffer. It fires up in the morning and when it's time to leave work, just don't stop along the way. Still does 80 no prob. Would a bad head do that? Found a plug opposite the fuel inlet. Is that the charge pump relief? It's round with 2 flats -10mm wrench.

[Toby]

How much WVO are you running per tank? That stuff is hard on pumps for a number of reasons, not the least of which is that even at 210* its viscosity is still too high. The VE pump is pretty durable, but not bullet proof. I suspect that the fuel is not hot enough to light off in a luke warm motor. Try extra glow plug time and see if that works. Try a shot of WD-40 as starter fluid (NOT ETHER) and see if it pops right off, next time. If that works you could always rig up a WD-40 injector system like old John Deere tractors did with ether.