87 300DT difficult start
 

Hi,

I have a 87 300DT with just over 200K. The problem with it, is starting.
After been stopped overnight, it will not start. When I crank the ignition
key, it looks like wants to start, but doesn't. If I am lucky, it eventually
starts. Another times it will not. I replaced the preglow relay, and the
problem didn't go away.

1) Should I replace the glow plugs? Because I don't have a meter to
measure the current without spelliting the wires, I have not tested the
wires and the plugs. I will get one today. However, the resistance of
the glow plugs #'s 1, 2, 4, 5 and 6 is 0.9 Ohms. I couldn't reach #3.

2) Can it be the temperature sensor? Yesterday, it was a warm day. The
car started at the third time I cranked the engine. I stopped the car
and 5 hours later, it started first time. This morning, it is much colder
here, I had no luck.

3) In another posts here, other owners mentioned having problems when
the injectors pump leaks. I see a leak on top of the injectors pump.
Could it be the cause?

4) Yesterday, I measured the voltage from the starter wire to the preglow
relay. When I cranked the engine, I measured 5 volts and while cranking,
the voltage went to ZERO. Is this normal? If not, what could be wrong?

TiA,
Demi

Just to satisfy my curiosity, please connect a voltmeter to one of the plugs and turn the key to the #2 position. Please confirm that you have 12V at the plugs for about 40 seconds after you turn the key to the #2 position.

RE: 87 300DT difficult start
 

Hi Brian,

I just measured the voltage, as you asked. Both #'s 1 and 6 have no
voltage. Actually, it is about 0.0007 and 0.0009 volts. What does it
mean, apart no current reaching the glow plugs? Bad glow plugs? Bad
relay? Bad wires?

Thanks,
Demetrio

Well, you have found your starting problem, that is for sure.

First question: Do you have voltage on the other four plugs? 12V?

If yes, it's time to check some wiring.

Remove the plug at the glow plug relay that sends voltage to the plugs. There will be six sockets in the plug.

Use your meter and check for continuity between each of these six sockets and the respective glow plug. I would expect that you will find continuity on each of them, but you never know.

If you have proper continuity of the wiring, the only thing that remains is the relay.

Used relay? Warrantee?

Demi,

Remove and insert the GP connector from the GP 10 relay times. Then check the voltage at all the GP.

Also, when you measure the resistance of the GP, you should do it thru the holes in the GP cable connector after it is removed from the GP relay. This removes any parallel resistances that will give you incorrect redings.

P E H

I was contemplating the advice from PEH and I concur with it.

It would be highly unlikely for the GP relay to function properly for four glow plugs while providing no voltage to the remaining two.

Additionally, you have installed a second relay with identical results.

This points to a potential problem in the connector at the GP relay.

You may not get continuity on the two plugs that you previously measured with zero voltage. Take a careful look at the sockets on the plug. Determine if there is any corrosion in those sockets prior to proceeding.

What about the 80 amp strip fuse? Would a crack in that cause these symptoms?

Hatteras,

Probably not. If the 80 Amp fuse was open, none of the GP would work. The 80 Amp fuse will not affect resistance readings of GP.

P E H

RE: 87 300DT difficult start
 

Hi,

I think I have found the cause. Eventually and after cranking the ignition key
for about 10 minutes (several times), I managed to start the car. After
started it run without any problems. Then my neighbor noticed big drops of
fuel from cylinder #5 line (on top of the injection pump). I stopped the car.
Two hours later, I tried to start the car. No problem. First time I cranked
the engine, it started. Switched off the engine. About four hours later, no
problems starting the car. Again, at the first crank. Then in the morning, I
tried to start the car. NO LUCK. After three tries I gave up. I think that the
injection pump gets dry and there is no fuel to fead to the engine. If I crank
the ignition long enough, the car starts. This happened before, about four
times so far, to be precise.

Questions: Do you think I am correct?
If so, how do I fix the leak?
How does the fuel line fits into the injection pump?
Is there any O rings to replace?

At this stage, I am thinking to take the car to the mechanic.

BTW, thanks to all for your advices,

Demi

It sounds like you have air in the lines, the seals at the IP outlets are probably the source of the air, there are O rings that can be changed and a minor overhaul of the Ip is probably in order. Is it also leaking oil at the end nearest the firewall?
Whats the history on that engine BTW? Original #14 head? Run it down to San Mateo, I know a place there that will put it right if you don't want to mess with it yourself.
Be aware that a member of the Shopforum here was experiencing a rather large amount of fuel leaking from the IP, and his engine (OM603 in an SDL) suddenly caught fire recently, the entire car was lost as a result before he had time to have the seals replaced.

RE: 87 300DT difficult start
 

Morning,

The problem is half fixed. The IP "O" rings have been replaced.

There were two leaks sources. Now there is only one. Why? The fixed leak
was on top of the IP. While the car ran, fuel come out. When I stopped it,
fuel shouldn't come out from the top. No pressure to push it out. If air gets
in the IP while the engine is stoped, it is because fuel is getting out (and not
from the top). This just adds to what I see now. If I stop the car at about
8:00 pm and start it at about 6:00 am next day, I have only to crank the
engine about three/four times. A far cry from the 15+ minutes it took before.
Without a second fuel leak, it is more difficult for air to get in and fuel out.

Question: How do I go around and discover the second leak? I did inspect
the engine while the car was running, but I saw no leak(s). A
friend sugested to squirt soap water, but this is not a gas leak.
This is a fluid leak. What should I do?

TIA,
Demi