524td won't start - flooded maybe?

[524tdAviator]

Lot's of possibilities of what could be wrong, but I had an issue with the alternator ground strap being corroded and not allowing the battery to stay charged when running. The car wouldn't start with a slightly discharged battery so I had my neighbor attempt to jump me - still wouldn't crank very fast after several minutes of jumping.

About 10 or so tries of trying to get the car to start I plugged in the block heater to bring the temp up from 35 degrees F to 65 degrees F. I then replaced the alternator ground strap with a 4 gauge (not 2 gauge unfortunately) ground strap. I tried about 5 more times and still nothing. I gave up and took the battery to get fully charged at a nearby auto parts store.

I came back with the charged battery and while the engine cranked over quickly it still wouldn't start. Not even a single sign of life. The glow plug cycle appears normal.

The only thing I can think of is I might have partially hydrolocked the engine with all the cranking and glowplug start cycles that emit all the fuel into the engine. I do have a leaking #4 injector (I still need to install a replacement I got from a forum member here) so maybe that's flooding the engine or decided to not function at all. The engine recently started consuming a small amount of coolant too (headgasket? leaking coolant hose?) - could also be a cause of my issues.

I have no idea where to start - I'm thinking about throwing in the towel with this car and junking it.

I'd appreciate any advice.

[524tdAviator]

Here's an update. I opened up the bleed screw for the fuel line on top of the fuel heater/fuel filter assembly and turn the ignition just before the start position to see if the fuel pump would run. Absolutely bone dry - no fuel moving out of the bleed screw.

Three months ago when I replaced the fuel filter I opened up the bleed screw to remove an air lock. At that time fuel was bleeding out no problem with the fuel pump going.

The battery is pretty dead with the attempted starting, but it does crank over a little bit. I'm assuming the remaining juice in the battery is enough to power the in-tank fuel pump so that I can confirm that it indeed does not work. Hopefully this is the case and I did find out that the in-tank fuel pump is the problem!

Question is - can I really use an in-tank fuel pump from a gas car? I've heard of people mentioning on this forum that it's possible to use it. I can pull one from the junkyard for very cheap. There is no 524td at Ecology in San Diego at the moment - only 528e and 535i models. I don't want to spend $480 on a new OEM diesel fuel pump.

[altus22]

If the engine still turns over, you did not hydrolock the engine.

If you don't get any fuel out of the bleed screw, then you are correct that the in tank pump is probably bad. Check to make sure that you have 12 volts on the terminals at the pump while the glow plug cycle is running. If you do and you still don't have fuel from the bleeder, then your pump is probably dead. Try the in tank pump from a gas car, the worst thing that can happen is that it isn't strong enough to pump cold, thick diesel. Do NOT use the high pressure pump (under the car) from a gas car.

Once you get the new pump in and bleed the air it will still take some cranking, so warm up your block again before trying to start it.

[Frybrid 524td]

Have you been using WVO? Did you properly purge your lines with diesel the last time you drove it on VO? Could VO have gelled in your lines?

[524tdAviator]

If the engine still turns over, you did not hydrolock the engine.

If you don't get any fuel out of the bleed screw, then you are correct that the in tank pump is probably bad. Check to make sure that you have 12 volts on the terminals at the pump while the glow plug cycle is running. If you do and you still don't have fuel from the bleeder, then your pump is probably dead. Try the in tank pump from a gas car, the worst thing that can happen is that it isn't strong enough to pump cold, thick diesel. Do NOT use the high pressure pump (under the car) from a gas car.

Once you get the new pump in and bleed the air it will still take some cranking, so warm up your block again before trying to start it.

I'm going to jump the fuel pump by jumping pins 30 and 87 to see if I can hear it running. Tomorrow I'm going to the junkyard to pull a fuel pump from a gas car. I'll plug the block heater in and recharge the battery and see what the new gas pump can do. Thanks for the advice!

Have you been using WVO? Did you properly purge your lines with diesel the last time you drove it on VO? Could VO have gelled in your lines?

Good suggestion, but I haven't been using WVO for a long time since I need to replace the PEX lines - one of them has cracked. I've heard of it being next to impossible to start after people not running the diesel purge cycle on the fuel lines before shutoff, especially in the cold.

[524tdAviator]

Ok, got the battery recharged again. The fuel pump does indeed work. I opened up the bleed screw and I'm getting a strong flow of fuel out of the little hole.

Back to the drawing board... could it possibly be the electric fuel shutoff solenoid? (Part #13512243295)

Tomorrow I'm going to remove a high pressure fuel hose to see if I'm getting fuel coming out of there to the injectors.

I found a replacement for $35 as opposed to $125 for the BMW solenoid. Should this work if I find it to be the solenoid switch?
http://www.ebay.com/itm/VW-Mercedes-Vol ... p=mtr#shId

[Frybrid 524td]

Don't remove the high pressure line, just loosen it at an injector. Fuel should bleed out. You can bleed each injector line that way.

Test for voltage at the fuel cutoff solenoid in the top of the rotary head of the IP.

[altus22]

Don't remove the high pressure line, just loosen it at an injector. Fuel should bleed out. You can bleed each injector line that way.

Test for voltage at the fuel cutoff solenoid in the top of the rotary head of the IP.

Yeah, test for voltage first. I had that wire break in the harness before.

[DieselBoost]

Don't remove the high pressure line, just loosen it at an injector. Fuel should bleed out. You can bleed each injector line that way.

Test for voltage at the fuel cutoff solenoid in the top of the rotary head of the IP.

Yeah, test for voltage first. I had that wire break in the harness before.

that irritating wire... main reason why my car stops sometimes...

[524tdAviator]

I fixed it! It runs now!

I confirmed that no fuel was moving beyond the injection pump to the injectors by opening up the fuel line at the #1 injector.

I cleaned up and moved around the electrical wire going to the fuel shut off solenoid, tested the top electrical contact with a circuit tester (the thingy with the light that looks like a screwdriver) and made sure power was getting delivered when moving the key to the run position. I got a positive indication of power being delivered, cranked the starter, and sure enough, it fired right up on the first crank. I'm gonna see about redoing the wiring to ensure that this doesn't happen again.

Thanks so much for everyone's help here!