Anyone speak diesel?

I've been wracking my brain trying to get this stupid VW Rabbit dieseasal going.

The previous owner rebuilt the injector pump, there were some air bubbles but I bled them out per the Shop Manual. I've been cranking and charging the battery for two weekends now to no avail. I pulled a glow plug out and it was newish looking with no carbon buildup.

Double check my theory:

Like spark plugs, the body grounds out to the block and the electrode where the spark plug wire goes, delivers power to the hot end inside the chamber.

I believe glow plugs are the same; ground the body, apply power to the end where the wire goes and it should get orangey hot in seconds.

So far so good?

I pulled the easiest one to get at, #4. Wrap a good sized wire around the hot lead, tighten it down, hold the body (threaded area) to the ground terminal on the battery and after 20 seconds I can still put my tongue on it. OK, I didn't, diesel doesn't agree with my delicate system.

I pulled the next easiest #1. Same thing.

Have I got this all wrong or can two glow plugs go bad at the same time? I ordered new ones but I don't want four perfectly good ones rattling around in my glove box when there's other stuff to spend $50 on.

Any thoughts?

Dan

Mine is third from the left.

I think you have a different problem. Glow plugs generally only come into play during lower temps. Some diesels (like my Cummins) don't have them at all (it heats the initial incoming air instead).

My guess is you still have air in the injectors.

A trick I was told when I ran my Cummins dry last Winter is to remove the intake hose from the air filter and crank the engine while holding something (your hand was suggested) over the intake to prevent any air from getting past. Since a cranking diesel will still want air, it'll suck the air out of the injectors. I haven't tried this myself (and hope I don't have to), but the theory seems sound. It does take two people, though - one to cover the intake and another to crank.

Ian F wrote: It does take two people, though - one to cover the intake and another to crank.

oh no, you mustve missed it - earlier he mentioned his car is a tiny little german thing, he can cover the intake with his hand from the drivers seat

Ian F wrote: I think you have a different problem. Glow plugs generally only come into play during lower temps. Some diesels (like my Cummins) don't have them at all (it heats the initial incoming air instead). My guess is you still have air in the injectors. A trick I was told when I ran my Cummins dry last Winter is to remove the intake hose from the air filter and crank the engine while holding something (your hand was suggested) over the intake to prevent any air from getting past. Since a cranking diesel will still want air, it'll suck the air out of the injectors. I haven't tried this myself (and hope I don't have to), but the theory seems sound. It does take two people, though - one to cover the intake and another to crank.

Will the diesel's suction give your hand a hickey?

I have zero VW experience, but on the MB 220D I had: The glow plugs were wired in series, like an old tymie Christmas Tree Light string. One goes out, they all don't work. They weren't grounded like a spark plug, but had 2 connections on the end, if I recall. You could check that with a meter. The motor wouldn't start regardless of the ambient temp without the glow plugs coming up first, unless it was already warmed up. You could get it started with a shot of starting fluid down the throat but you're not supposed to do that. You could also Aggie rig the thing with some jumper cables jumping around the dead glow plug so the other 3 would get power.

Anyway, pull a glow plug and start poking around with an Ohm meter and see what you have. Then put it back together and make sure you have +12v on the things. Maybe the control circuit is bad. Maybe that was the problem the DPO was trying to fix when he pulled the injection pump.

I also found that bad timing on the injection pump would cause the motor to eat glow plugs. I don't miss that car a bit.

Dr. Hess wrote: I also found that bad timing on the injection pump would cause the motor to eat glow plugs.

That's also a thought. The engine definitely won't start if the timing is off.

Again - given a warm enough ambient temperature (and we definitely have that right now...), a diesel should start w/o glow-plug assistance so you either have a fueling or timing issue.

Yep, I'm pretty sure that you need working glow plugs on these motors in order to get them to start from cold. They might take a minute or two to heat up but you should notice that they're warming up pretty quickly.

An indirect injection (IDI) motor like an old VW may or may not start without glows no matter how warm it is out. If its tired or has other issues, it won't go. A strong IDI motor might start without glows in 70+ degree temps.

If you are sure you have most of the air bled out of the system, a few other things you can check:

Do the glows have unburned diesel on them? As the glow plugs typically sit below the injector on an IDI motor, if you are getting fuel while cranking, the glow plugs will be wet.

Do you have +12V to the glow plugs when the glow plug light is on?

Does the glow plug light come on on the dash? Can you hear a relay click?

Do you have good cranking speed? 350 ish RPM is the minimum to start those engines.

Crack open the lines on top of all the injectors, or all you can reach, and crank the engine till fuel comes out of them.

Make sure the fuel shutoff on the pump is moving properly, and coming into the correct position to allow fuel to flow when the key is turned to "run" and "start"

Worst case scenario, if it has a manual transmission and you are certain everything else is good to go (you have bled the system best you can, fuel filters are good, fuel shutoff is in run position), gotta flat tow that bish with it in gear, tow it around the block at a pretty good clip, 1500-2000 RPM is what you are shooting for. If everything else is good, it will fire.

A friend had one of those in the early 90s. At 100K+ on the engine it was a PITA to start in warm weather and in cold weather it took a half a can of happy juice to get it to burp. His trick was a 500 watt bulb aimed at the block. That would preheat the engine enough to get it to start in the summer. In the winter it still took ether. The ether finally blew the crank out of it and he was glad to see it go. I don't remember how the glow plugs were wired.

Quick test for glow plugs- disconnect all 4. Hook your 12v test light to the POSITIVE post of the battery. Now, the light will glow whenever you touch anything grounded. Touch the glow plug terminals, one at a time. Test light lights, glow plug good. Test light no light, glow plug poo.

All good, reconnect all, turn key on and immediately check for power at the glow plugs. Power good, still no start, bleed injectors, then overbore and replace pistons. No power, find (sometimes) a big fuse on the firewall maybe, or find the timer relay and check for power there. there is also a temp sensor on the engine that adjusts the on time based on engine temp.

This is all painful and possibly inaccurate memories from before I banned VW and diesels from my shop.

My Cat starts first revolution at warm ambient. I believe if. Compression is good, timing is riight, spray/injection is correct and fuel is clean it has to fire. First thing I would want to know is the level of expertise of the injection pump rebuilder.

i use to do a lot of work on those POS motors,early VW diesels, best thing i ever did for a customer,WAS put an ISUZU 1.8L turbo engine in the car.

he loved it, more power, better on fuel , and bullet pruff, drove it to california and back couple times.

the only diesel worse than the VW, was the famous oldsmobile diesel.

914Driver wrote: I've been wracking my brain trying to get this stupid VW Rabbit dieseasal going. The previous owner rebuilt the injector pump, there were some air bubbles but I bled them out per the Shop Manual.

Did he rebuild it or buy a rebuilt pump? Pumps, even simple ones, are very easy to screw up.

Is it Timed correctly?

Think of an incorrectly timed pump like an incorrectly time distributor on gasser. If it's off, she won't start at all.

Also Air inside the system will kill it faster than anything.

http://www.greenbaypartsworld.com/vw/vw_injector_pump.htm

I had 3 out 4 glow plugs on my 95 Golf TD go bad. Made it a little hard to start in North Bay, ON in Jan!

I would check the timing of the pump. You'll just be wasting time if that's the problem, so just double check it. By the sounds of it, I'd be willing to bet its off since the PO didn't even bleed all the air out, I wonder how familiar he was with diesels.

With that checked, I would do like someone said above, pull a glow plug after cranking (floor it, these things don't need vacuum, and you'll be sure to be pumping in fuel), and look for unburnt fuel on the glow plug. You can also check if the plugs are working by watching the voltage at the battery, glow plugs are a pretty big draw and you'll see a fluctuation in the battery voltage.

If it;s just the Glow plugs it will start on ether. My 6.9 needed a shot the first start of the day regardless of how hot it was outside. Like an idiot i eventually fixed the glow plugs and on a cool november night it started right up for the person who stole it.

It doesn't sound like you're happy with that engine. Are you going to be blown away delighted with a perfectly humming VW deisel? If not, why keep it as is?

MrBenjamonkey wrote: It doesn't sound like you're happy with that engine. Are you going to be blown away delighted with a perfectly humming VW deisel? If not, why keep it as is?

I have an Audi 2.0 in the wings.

93gsxturbo wrote: An indirect injection (IDI) motor like an old VW may or may not start without glows no matter how warm it is out. If its tired or has other issues, it won't go. A strong IDI motor might start without glows in 70+ degree temps. If you are sure you have most of the air bled out of the system, a few other things you can check: Bled at the Injectors. Do the glows have unburned diesel on them? As the glow plugs typically sit below the injector on an IDI motor, if you are getting fuel while cranking, the glow plugs will be wet. Very little unburned fuel on them. Do you have +12V to the glow plugs when the glow plug light is on? Yes. Does the glow plug light come on on the dash? Can you hear a relay click? Light's on, no audible click. Do you have good cranking speed? 350 ish RPM is the minimum to start those engines. Yes, new battery helps. Crack open the lines on top of all the injectors, or all you can reach, and crank the engine till fuel comes out of them. Done. Make sure the fuel shutoff on the pump is moving properly, and coming into the correct position to allow fuel to flow when the key is turned to "run" and "start" A VW Caddy forum (British folk) tell me there's a fuel shut off that kills fuel when the key is off, otherwise you wouldn't be able to shut the car off. Worst case scenario, if it has a manual transmission and you are certain everything else is good to go (you have bled the system best you can, fuel filters are good, fuel shutoff is in run position), gotta flat tow that bish with it in gear, tow it around the block at a pretty good clip, 1500-2000 RPM is what you are shooting for. If everything else is good, it will fire. If it gets to that point it goes right in the river, it's pissing me off.

Thanks for the help guys, but this has to go on the back burner for a few days. My wife was driving the Ranger home and asked about the spare tire, seems it passed her doing about 70.

Yesterday I noticed the truck had a bit of a port list. Further inspection revealed that when the spare took flight, it hit the leaf spring and punched out the rusty spring perch. I'm into two spring perches, tow shackles and some time wiping rust off my face.

Dan

No but I'm fluent in Jive.

Damn dude, sounds like a bad situation. I agree you may want to pull the timing covers at this point and double check the timing is proper.

Also make sure the fuel shutoff is working properly. Do you ever see any white smoke coming from the exhaust pipe when cranking? Will it run on ether or WD-40? (disconnect the glow plugs entirely before attempting to start on ether)

Yeah I get white smoke (a new Pope?) I was afraid of putting wnything down the tube but diesel because a guy on the VW Caddy board blew a head gasket with starter fluid.

How do I check the fuel shut off?

Dan

My oldest brother uses a VW wibbit diesil on his saw mill and drives an oil burner too.

He's got a sorce for cheap OEM parts down in Maryland area.

Hi old FORD back hoe with an up draft throllte body Diesel will not start with out a fogging even with the glow plugs lite for 5 minutes before off a seperate battery it's just old and tired (can't blame it its 40+ years old and worked hard) He uses a plant sprayer (the type you pump up). mixes diesel with a bit of stale gas (out of what ever junker came in to the lot) and a bottle of dry gas. warm up the glow plugs....fog the intake and crank. gack...gack...nock nock nock....

If you are afraid to use a snort of Ether to get it running, two suggestions.

1. With the glow plugs connected: Hair dryer/heat gun down the intake for 10 minutes. Block heater plugged in for a few hours before hand if available. Get it good and nice and warm and see if it will start. Also report the amount of white smoke you get, if it does not start.

2. With the glow plugs DISCONNECTED: Block heater plugged in for a few hours. Use some WD-40, which is far less volatile than ether, and spray it in the intake AS THE ENGINE IS CRANKING. This will minimize any chance of head gasket damage.

If neither of those practices get the engine to at least start and run for a few seconds, especially #2, its time for a compression and timing check.

Regarding the fuel shutoff, it would be the only electrical thing on/near the high pressure fuel pump. I do not know which way it works exactly on a VW, but as thats a rotary pump, there is a swash plate inside the pump that moves to a "0" position to stop fuel flow. Look for a lever on the outside of the pump with a solenoid attached to it. Disconnect that lever from the solenoid, make sure it moves freely through its complete range of motion, reconnect to solenoid, make sure the solenoid moves the lever through its complete range of motion.

Also since this was a military vehicle as I recall, make sure the key solenoid for fuel shutoff was not replaced with a mechanical cable.