Inlection Pump and Cold Start Handle

[UpstateDieselGuy]

Well I've been running the car for a while now and love it.  Little by little I am working thigs and bringing it up to snuff.  I have still not overcome the cold start issues I have had from day one.  A local guy that works on these and has a '91, turned up a bit, believes that first off I need new glow plugs.  This isn't that big of a deal and I can change them out, possiblely without removing the injector lines.  The other part of this is that when it starts and I pull out the cold start handle it changes the engine sound, but that's it.  It still stumbles a little and sounds bogged down.  Once up to temperature it is fine.  The local guys when pulled changes the sound and ups the engine speed.  I have adjusted it according to people on here and him and still no change.  It moves the little lever on the side of the injection pump and that's it.  Is there supposed to be another cable to the throttle?  Is the engine speed adjusted inside the injection pump?  If this is the case is it repairable or do I have to replace the injection pump?  Sorry for the long post.  Just trying to tweak this thing out.  Thanks in advance, Chris

[tylernt]

Well my knob doesn't change rpm either, but I just found out my injectors are shot so maybe that has something to do with it.

I can tell you there's just one cable/lever for the CS knob, and it doesn't do anything to the throttle cable. At least, not up to '84, it doesn't.

[UpstateDieselGuy]

Cool.  I found out that the guy I bought it from has the old engine still.  Might have to put the injection pump from that on this one as well as some injectors and fresh glow plugs.  I will change the timmimg belt while I'm at it, that ought to be fun  

[entuzijast]

I have ECO, and old pump (without LDA) did make rpm go higher...But the td pump (I swaped) doesen't..
AFAIK TD pump just advances timing, they don't make rpm go higher...

[Adam]

*shrugs*

All I know is that the CS advances timing by 5 degrees.

RPM's however, I have no idea.

[LeeG]

on my '91 TD, first notch of CS just advances timing, no RPM change.  2nd notch ups rpm by about 200.

[dieselpete]

the older injection pumps just advance the timing,
while the newer (not quite sure what year they started I believe it was 86) also have
the extra step in the lever to raise the rpm to make the car run smoother
maybe someone swapped out the original i/p at some point
p.s. the rpm increase is internal in the pump
 

cheers pete

[RabbitGTDguy]

*shrugs*

All I know is that the CS advances timing by 5 degrees.

RPM's however, I have no idea.

Cold Start should only advance injection timing by 2.5 degrees from what I remember...  how did you verify 5 degrees?

[fspGTD]

2.5 degrees advance relative to the motion of the camshaft or the pump input shaft is 5 degrees advance relative to the motion of the crankshaft.

[Edited for clarity ]

[UpstateDieselGuy]

This might be what I am seeing here, an older replacement engine that did not have the engine speed control built into it.  I am planning and hoping that the parts from the original 1991 engine will bolt up.  I'm not worried about the injectors, glow plugs, or injection lines, however I am kinda coincerned about changing the injection pump and timing belt.

[RabbitGTDguy]

*shrugs*

All I know is that the CS advances timing by 5 degrees.

RPM's however, I have no idea.

Cold Start should only advance injection timing by 2.5 degrees from what I remember...  how did you verify 5 degrees?

Good call jake, but even though that is true if we are talking timing specific the actual timing of the motor is not changed with the pull of the cold start, only the pump timing is changed internally ...thus, 2.5 degree of advance on the injection pump. Wouldn't that be neat if it was a change at the crank...

Joe

[Mark(The Miser)UK]

*shrugs*

All I know is that the CS advances timing by 5 degrees.

RPM's however, I have no idea.

Cold Start should only advance injection timing by 2.5 degrees from what I remember...  how did you verify 5 degrees?

Good call jake, but even though that is true if we are talking timing specific the actual timing of the motor is not changed with the pull of the cold start, only the pump timing is changed internally ...thus, 2.5 degree of advance on the injection pump. Wouldn't that be neat if it was a change at the crank...

Joe

Ha ha
Pull the lever and hole a piston? Not sure how neat it would be ;o)
 A kind of reverse detonator plunger!

My current Quantum the cold start makes no perceptible difference (timing set to 1mm) Starts on 1st/2nd crank down to -5 either way. Previous Quantum never had the lever connected in 3 years that was the 60mpg imp one )

[RabbitGTDguy]

Thats what I was implying VW's own self-destruct mod...  Scary stuff...

[Adam]

*shrugs*

All I know is that the CS advances timing by 5 degrees.

RPM's however, I have no idea.

Cold Start should only advance injection timing by 2.5 degrees from what I remember...  how did you verify 5 degrees?

That's only what I read in my A2 Bentley manual.

[dieselweasel]

*shrugs*

All I know is that the CS advances timing by 5 degrees.

RPM's however, I have no idea.

Cold Start should only advance injection timing by 2.5 degrees from what I remember...  how did you verify 5 degrees?

Good call jake, but even though that is true if we are talking timing specific the actual timing of the motor is not changed with the pull of the cold start, only the pump timing is changed internally ...thus, 2.5 degree of advance on the injection pump. Wouldn't that be neat if it was a change at the crank...

Joe

Remember guys that we're talking about timing advance in reference to degrees of crankshaft rotation before top dead centre at which point injection occurs.  Therefore it is most appropriate to refer to timing advance in relation to the crankshaft.