84 Caddy 1.6 started up with problems

[hvfnet]

  Hello all,

  I am new to this Forum as of today.  I am looking for some basic information on this Diesel.

History:  I bought about 6 months ago. And all I have done is drive it!!   It has been extremely dependable.  Getting low 30's in MPG.  (Short of the 50 I was told to expect)  However, It   does have a drip from below the fuel tank, and the motor had some oily dampness  (thought it was the valve cover gasket)

Problem:  Even with the above ills,  just hit the glow plugs for 7-10 seconds, turn the key and it was running before you could hear the starter engage!  So today I finally got the ambition to run the car up on ramps to identify/fix the fuel leak from under the vehicle.  When I went to run it up on the ramps, I excellerated and pure BLACK smoke/carbon shot from the exhaust.  At the time I thought it was odd, but not significant.  I dried up the wet area on the fuel tank (waiting to see fresh leakage to identify the source),  also found a cracked return line on the injector that was the source of the wet engine. I fixed that.  Then when I went to start it up to bring it off the ramps, it would not start!!!  So  I topped off the fuel tank, and changed the fuel filter.  now It will start to chug, and sometimes run for short periods with no power, and the throttle position does not affect the speed.  I thought I had air in the system.  So I took off the filter, filled it with diesel, and re-installed.  Now it will start and run for 30 seconds or so, but when the filter is removed, it is empty of fuel. 

I believe I have a fuel delivery problem to the filter.  Is there an electric pump in the tank like in gas vehicles?

Any help in diagnosis,  or confirming I am going in the right direction is greatly appreciated!

Thanks in advance

[rabbitman]

These don't have an intank pump, the injector pump has it's own lift pump.

Maybe you need to blow the line from the tank to the filter, remove the filler cap so the tank doesn't go pop

[Familydiesel]

Yeah, I think Rabbitman has a good idea.  It sounds like either you still have air in your line, your system hasn't been bled properly, or the injection pump isn't drawing the fuel properly.  

It may be possible that you have a cracked inlet fuel line (either the line going from the fuel line (behind the fuel filter) to the filter, or the line from the fliter to the injection pump.  So check these to see if either is cracked, leaking at all.  Since your injection pump sucks the fuel to itself, any air leaking into the systerm will affect its ability to "prime" and draw fuel.

But Here is a way to bleed your system to make sure you have removed all the air.   This is what I do to bleed the system.  Before you put pressure to the tank, remove the inlet line at the injection pump (the line that comes from the fuel filter to your injection pump) and place a small container underneath the loose hose.  Disconnect the return hose at the injection pump and screw a bolt into the end of the hose to keep any fuel from coming out.  Then put pressure to the tank until you see fuel coming from the inlet line.  Then hook up all the hoses, and loosen the injector fittings at the injectors.  Disconnect the glow plugs (it would be good to disconnect the glow pugs by either removing the relay, or disconnecting the line going to the glow plug bus, and tape the end so that it won't touch anything when you turn over the motor),  then crank the motor.  Crank the motor, with the throttle pushed to full, until fuel starts to come out of each injector fitting.  Tighten the injuector fittings, hook up the glow plugs and fire it up.  


If your lines check out, and you bleed the systerm, then it may be the injection pump that isn't pulling fuel.

If you still have a problem, then post again, and we'll try to help further.