No, no, no, no, no, no, no. Don't mess with the IP before you get the glowplugs working.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Understood. IP stays till the glow plugs are sorted out

It sounds like your relay is not working correctly. You can hot wire them as I described, temporarily to see if it starts.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

I agree with previous posters, don't touch the IP until you exhaust all other avenues of troubleshooting. It's absolutely the last resort for troubleshooting. And pop test the injectors too before pulling the IP.

GP relay assembly is on the driver side fenderwell. Take the cover off the GP relay and check the flat fuse in there. Pull it out and physically inspect it. Sometimes they develop a hairline crack that will mess with the GP circuit. Then check the voltage at the fuse when the relay is energized and current is flowing to the GPs. Have a friend turn the key for you while you listen for the relay in the engine bay. If you have zero volts (or close to it) at the GP relay, check the connection of the heavy red wire to the GP relay assembly. Clean the connection if it warrants it. You can check voltage drop to this terminal while the relay is energized by checking voltage between the positive battery post and the fuse in the GP relay. This will be zero when the GP is de-energized, but should also be near zero when it is energized. If there is any significant voltage drop, check and clean all the connections between the battery and the GP relay fuse (follow that big red wire out of the relay assembly back to the battery.) In later model W123s, there is a terminal block C105 located just at the edge and basically centered on the wheel well. This terminal block contains connections to the alternator, starter (this is the connection to the battery) and GP circuit. The electrical diagram for your model shows all these connections coming off the starter, but that may or may not be accurate, I never owned an '80 300TD. If there is no terminal block in the right fenderwell follow connections off the main starter terminal or battery.

If you have good voltage at the fuse while the relay is energized, but zero voltage at the GPs themselves, then the relay contacts are bad or the relay isn't working right. It's the only connection between the fuse and the GPs so look in that area.

The light in the dash going out after a few seconds is normal. In a properly working system and in warm weather a cold engine should start with minimum cranking at that time. If the key is left on without cranking, the relay will de-energize after about half a minute. You should hear that click even from inside the car.

__________________
mjk

'84 300SD 119KMi (Liesl der Diesel)
'84 300D 326KMi when the oil left (former parts car)
'82 300SD 253KMi (new parts car)

Is it warm there today? Can you move the car so the engine bay is in the sun for the hottest part of the day? Leave the hood open. Ditch your jug of fuel, and hook the car up to a can of diesel purge. Keep working on your glowplug troubleshooting while the car is "cooking". After he's gotten a good suntan, spray a bunch of WD-40 into the intake, then crank it a few times. Make sure you have a REALLY hot battery, too. The key is to crank it a couple 5-6 times, spray a little more wd in the intake, run the glowplugs, crank 5-6 times... be patient. AND KEEP YOUR BATTERY FULLY CHARGED. If it starts to catch, push the accelerator to the floor and keep cranking. Then charge your battery back up before the next attempt.

Jay.

__________________
On the road, currently:
'83 300D (German spec.) 168k mi. - - Wolfgang (tucked snugly away for the winter!)
'87 300D 375k mi. - finally went over to "The Dark Side"
'87 300TD 225k mi.
Cannondale 66cm CAAD5 w/Campy/Jamis Aurora
Hujsak Custom Fixie/Landshark Track Shark Custom/Ahearne Custom 29'er

I am really suspecting the IP now, I test all the glow plugs, they are all good, bypassed the relay, and I know they are warming, but the IP is putting out almost no fuel pressure, removing the lines and cranking the engine, which on my 1.9l TDI or 1.6l IDI would squirt fuel everywhere, it just dribble lightly on each stroke.

Can anyone tell me if their pump squirts strongly when they crank it over to bleed the lines?

even with the line full disconnected from the injector it seeps fuel??

Are you sure your getting fuel to the pump. Try running it off diesel from a bottle with the inlet and return hoses in the bottle to ensure its getting fuel, also be sure your primer pump is not leaking.

__________________
1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

Already doing that, its running off diesel from a gatorade bottle.

Its getting fuel, and the injector lines seep fuel disconnected, it doesn't look like enough pressure to fire off the injectors. However, on any other diesel I've worked on, the fuel will spray out while cranking, instead of just kind of seeping

I've bled it multiple times, all the lines are air free. It just BARELY puts out fuel, not any sort of good strength.

Does there seem to be a lot of fuel from the return line when cranking?

I guess it possible that the fuel pressure return valve is stuck open since it was running on the CRAP fuel. Pinch off the return line and see if you get more fuel pressure at the injectors.

__________________
1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

Assuming the individual stopped driving the car because it would no longer run.Or was getting quite cranky. The injection pump and perhaps even other things might be full of undesirable stuff.

I would fill the injection pump with a solvent like laquer thinner and see what I could pump out of the return line after twenty minutes soaking.Capture it to examine it. Lot of foreign stuff comes out soak it again. For both operations use the finger pump.

. Do not try to run the diesel engine on laquer thinner. Pump new diesel in first before cranking the engine over to displace all the thinner and other crap it may break down if in there.

You especially do not want to feed the crap through the injectors. Plus laquer thinner burns like gasoline. New secondary filter for sure as well. The laquer thinner is agressive enough to really dissolve problem buildups reasonably fast in comparison to many other solvents.

Some people have dumped almost anything into the fuel tanks.Properly done you can get away with it. Unfortunatly too many just believed the myth of just dump whatever they found in. Sure it will run but the question becomes how long.

For a diesel engine to start I was always led to believe that you need air/heat, fuel, proper compression, and of proper timing of it all.

Where I am going with this is: You have isolated the fuel supply, and it sounds like you are getting fuel, possibly low pressure, but some fuel. The air intake should be fine, but it would not hurt to check it.

Glow plugs. Pull the wire off the plug and put your red/positive voltmeter probe on the wire, and the black probe on a good ground. Have a helper cycle the ignition switch and see if you get voltage at each glow plug, and for how long.

Lastly, have you checked the static/basic timing of the motor. Chances are slim, but it could be out of time. A good valve adjustment might not be out of order either. If the valves are out of whack, you will not get proper compression to start/run.

Just my .02 you are headed in the right direction, let us know how it goes!

__________________
2012 Mercedes ML350 Bluetec 91K (hers)
2005 Corvette 55K (fun car)
2002 VW Jetta TDI 231K (mine)
1998 Volvo S70 T5 Turbo 196K (kids)
1994 Ford F150 4WD 249K (firewood hauler)
1983 Mercedes 300D 376K (diesel commuter)

Agreed. Glow plugs are good, checked that, and they tick off properly now

Even if I am getting low pressure, if there is not enough pressure to open the injectors the engine will never run. It seems like the compression is low, but it should still cough aggressively with low compression and glow plugs

Anything wrong with pulling it to get it started?

Have you tried spraying some WD-40 into it to get it started?

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Have you tried pull starting it yet?

__________________
Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving