1978 300D will not stay running
 

Hey Everyone,

A buddy of mine just purchased a 1978 300D for $1000, a great looking car for MI, it's even solid underneath!, here is the ad:

http://kalamazoo.craigslist.org/cto/1727262694.html

Anyways when purchased the car needed a starter, after talking with the fellow he seemed very knowledgeable about cars and diesels, and we trusted him that this thing just needed a starter. He stated that the compression was around 380 across all cylinders, should be plenty to start. He also did a valve adjustment himself a week before the starter went out, and he said after completing the valve adjustment the car sounded more like a cummins, strange I thought.

Well anyways we just got done putting a new starter on the car, and the first time after cycling the glow plugs it started only after stepping on the accelerator. We ran it for a good 3-4 minutes and the entire time it was emitting a whiteish smoke. As soon as I tried to put it in Drive the car died. I could not get the damn thing to start again, finally after killing the battery I jumped it off of another car and got it started.......and then the same thing happened, it died when I tried to put it in drive!

I also noticed that the oil pressure was quite low, around if not below 1. I really hope this guy didn't just screw us over, if you read the craigslist ad you will see all of the work he has done to the car, so he knows what he is doing (or so it seems).

My thoughts:

He just adjusted the valves himself a week before the starter went out, if he adjusted them wrong could he have lowered his compression to the point where it wouldn't start easily? He told me even before the valve adjustment he had not problems ever starting the vehicle.

Also with oil pressure this low should I be concerned? The lowest my 240 has ever dropped to is 1.5, and that is after a long highway drive. This is sitting at or below 1 and doesn't shoot up right away, although it does rise as RPMs increase.

Please let me know your thoughts, I plan on buying a diesel compression tester this weekend and checking compression, but I want to make sure I understand what can cause whiteish smoke, low oil pressure, and a no start/stall when under load condition.

Thanks for your help!

white smoke eh.
sounds like a cracked block. or head gasket issues.
pull all the injectors and get a compression test done. pull the radiator cap, look in there for oil residue. if the radiator is full, and the coolant looks good, have someone crank the car while you watch the waterneck, if it's bubbling, odds are good it's blown.
what does the smoke smell like? oil? water? fuel?
if it's fuel, a poor valve adjustment could easily account for it. pull the valve cover, and look and see if an intake valve got exhaust clearances, and vice versa...

Hey thanks for the info, I will have someone crank the engine and look at the coolant. The white smoke smells like fuel, and not coolant so hopefully the block is not cracked :eek:

Still don't like that low oil pressure though.......

Put another gauge on it to make sure it actually has low oil pressure.
Can you rev the motor when you start it?
You could have a fuel delivery problem.

I will try a different gauge and see, once it is started I am able to rev it, but it still dies when put into drive. I forgot to mention something important, PO said this car had an entire WVO conversion in it, which was removed before I purchased it. I might have to get some Marvel Mystery Oil.......after a compression test of course.

The wvo says it all. I dont believe the compression numbers he gave you.
You may need to go right through the fuel system as well.
The car has probably had problems for a long time, hence the starter failure.
As one past member once said " the motor has suffered from Death in a jug"

I was starting to think that, considering the fact that he has replaced an awful lot of parts on the car. Sorry if this is a dumb question but can I do a compression test through the glow plug holes or do I need to remove the injectors? Also if I test using the injector holes, should I disable to glow plugs or wont it really matter?

You can do a comp test through the GP holes. You should make sure the GPs are electrically disconnected before you start.
What other parts has he replaced?

Pull the plastic cover off of the Glow Plug Relay and you will find 2 Electrical Connectors. Pull either or both of the Connectors.

If you only disconnect the wires at the Glow Plugs and let them hang and one of the wire end ground on the Engine Block when you try to start it will cause a Short and you will burn your Strip Fues on the Glow Plug Relay.

Also try loosening the Fuel Injection Hard Line Nuts at the Injectors to Bleed the Air out of the system. You want to see Fuel coming out from under the Nuts Before you tighten them and try to start.
When Air gets trapped between the Fuel Injection Pump and the Injectors the Air inside the Hard Lines compresses a lot and moves very little resulting in stress on your Battery and Starter.

Thanks for all of the advice, I will make sure to follow the instructions when I get a diesel compression tester. As far as parts that have been replaced, here is what I have been told or could see myself:

-Both Fuel Filters
-All Glow plugs and GP relay (about 2 years ago, replaced with the pencil style plugs, I am going to check all of them as the GP light does not come on at all, although I do have power on both sides of the strip fuse on the firewall when I turn on the ignition)
-Injection Pump (replaced with a euro pump)
-Battery Ground Cable
-Valve Adjustment Done

Many other items have been replaced as well, but all others items do not have to do with my current issue or the engine whatsoever.

before getting a compression tester, I'd pull the valve cover and verify the lash on the followers. get the right feelers, (.10 and .30mm i think) be sure and measure between the cam, and the follower, not between the follower and the valve! and be sure you follow a chart with the valves position on it. that way you know you won't make the mistake I think he did.