Diesel Cranks but No start :(
 

Hi! My husband has a 1984 300DT which was running and great up until last week. He took the car to work and when he went to start it at the end of the day it wouldn't start. One of the glow plugs was cracked so they replaced it but it still wouldn't start. After a few hours and no luck starting it they started it with ether and it started right up.

Here is what he did so far.

He changed all the glow plugs, changed the air filter.

He changed the 2 fuel filters and bled the fuel lines, and it started right up but then after sitting over night again...no start just cranks.

He cracked the fuel injectors open (while cranking the engine) to bleed air out of the lines and it started right up on the 1st one but then after sitting over night...no start just cranks.

Then the next day he bled the rest of the injectors and it started right up again but fuel leaked from the 1st injector so he tapped it in more and it stopped leaking but still after sitting over night it won't start.

He's also getting white smoke out of the muffler.

Once he gets it started it will start again and again, even up to an hour later but when it sits overnight it won't start in the morning it just cranks.

Any ideas on what to try next. Thank you for your help!

Welcome to the forum.

He has done quite a bit, good.

It does seem as if fuel is leaking back somewhere. Replace all the fuel lines and install a new primer pump.

I don't understand the "tapped it in more" statement, the injectors are threaded.

White smoke may be an indication of oil or water in the combustion chamber. Does the white smoke smell of antifreeze? What color is the oil on the bottom of the oil cap?

Ok, I checked the oil cap and the oil's black. The white smoke doesn't smell like antifreeze, it just has that diesel car running smell.

The tapped in on the fuel injector was just my wording. Sorry about that, he said he tapped the wrench alittle more (he didn't want to overtighten it) he didn't actually hit or tap the fuel injector.

Okay, seems to be just some oil, a little is normal.

To properly tighten the injectors, you need to remove the jumper fuel lines, to get a good grip. Use a socket instead of an open end wrench. 27mm or 1 1/16 inch deep socket.

Has he checked the fuel lines at the tank? Also what condition are the fuel and return lines under the hood? Is the tank screen getting clogged?

remove the fuel cap, and see if you still have issues starting it. if not, you have a tank vent clogged. if still problems, your primer pump could be leaking fuel, and letting air into the system. also, all the small lines on each injector could be letting air in, or one of the fuel lines from the tank to the pump... also, your fuel filter 0-rings could be bad.
a simple way to find leaking fuel lines, is to put a shop vac in blow mode, and stuff it into the fuel filler neck, then look for fuel leaking out of hoses.:D

What about a bad glow plug relay? Has he verified there is voltage to the new glow plugs?

Yeah, check the glowplugs. 90% of no start conditions on these engines are caused by malfunctioning glowplugs. I don't see any mention of troubleshooting the glow system, only replacing plugs.

Shouldn't need glow unless it is colder in NY. Start after bleeding indicates air leak.

Ah the joy of a new Diesel. Be patient, you'll find the problem. All of the suggestions have it about covered. I'll put 50 cents on the glow plug relay and $1.00 on the leaking return lines. Any takers?

Since it will not start after sitting over night and when you Husband bleeds the air if at the Injectors it will start an run normal until it sits again; it sounds like you have an Air Leak in your Fuel Inlet hoses or from your Hand Primer.
This is causing your Fuel Supply Pump to "lose its prime".

The Fuel Hoses can be replaced for $1.20-$1.50 per foot from any Auto Parts store as their Regular Fuel Hose is also rated for Diesel Fuel. The size is 5/16 of an inch inside diameter.

If you still have the Old Style shiny Aluminum bodied Hand Primer on the Fuel Supply Pump (mounted on the side of the Fuel Injection Pump) that is often the cause of air leaks. Get only one made by Bosch as some of our members have reported not so good quality control on some of the copies. The Bosch one is between $20 and $30 on the internet.

A less likely possible is one of the plastic Valves inside of the Fuel Supply Pump is not sealing well. The kit for that is sold at Fastlane in the parts tab at the top of the page and is around $11+shipping.

If He did not ream or otherwise clean out the Carbon from the Glow Plug Holes He should do that before Winter so that the new Glow Plugs would last longer.

the buy parts link above on fastlane has the black bosch primer for 21.00 and a new aluminum style for 31.00 I've heard that no matter which one you buy you get the black one, so beware before ordering...

Welcome to the forum,
We all hope that you can find out all you need to know so that you can enjoy your car.

To determine if you have an air leak causing the problem, make sure the tank is at least 1/2 full, park the car on a hill facing down hill overnight. If it does not have the problem in the morning then probably you have an air leak into the fuel system.
Given he changed the filters, probably the leak is some where around the filters, my guess it the bolt holding the secondary filter on.

He checked a few lines yesterday and replaced a couple around the fuel injector area. But no start this morning. He's going to change some more tonight. He tried to test the glow plugs and relay but our ohm meter did not want to work. It does buzz, then the light goes out and you can hear a click when the glow plugs are ready (no change from when it was starting on it's own). But, we'll have to get a new ohm meter to be sure. I hope it's just an air leak somewhere, but how to find it. This is his first diesel. He will keep trying and I will keep you updated. Thank you so much!

I forgot, I tried taking the gas cap off yesterday too and no start. Also the primer pump does look like the original. Looks just like the one in the picture in the Haynes manual.

When he primed the pump yesterday fuel came out of the pump is that normal or is that a sign that it's definately leaking?

Also does anyone know of a diagram for his car's engine that labels all the lines and hoses?

And it is very warm here, around 60 degrees in the morning. But I do try to start it in the afternoon too and by then it's close to 90 degrees the last couple of days and no start.

Some of the injectors had black rings (broken) on them and some didn't have any rings at all.

Last question, for now :), is there an easier way to find an air leak other than just looking?