Advance springs and shims

[boosted_diesel_84]

i remember reading a post about changing the spring and shims in the advance on the pump. if this was performed incorrectly, could it cause hard cold starting? because the shop that screwed up my pump did this "MOD" and i have hard time startinf when cold, lots of smoke. and ive already

-checked, double checked and tripple checked timing, 1.05mm cam and crank are lined up also
-rewired glow plugs, getting ovver 12v at plugs
-tested plugs, all have same resistance, and turn red hot in about 10 sec.
-nozzles are new

[dillenger1]

I would like to see some stuff on this.My pump i built didnt have any shims on either side.I have the green spring too.This advances with pump pressure correct?My pump is kinda jumpy off idle for a second.i was wondering if this was gov. related or timing advance?

[burn_your_money]

How does the car drive?

[boosted_diesel_84]

its a lot faster than what it was before everything was gone thru, but hard cold starts, lots of smoke, and sometimes, u can rev the motor and get black smoke, other times, nothing, also sometimes she will boost to 20 psi no prob, and others it will only go to 10 psi with no smoke and not want to make any more.

and i was only able to turn my pump up about 1/2 a turn from where shop set it on main fueling, and now it will stay revving between shifts, and if u rev it out, will stay reved at the top, it didnt do this before the pump was built until it was turned up about 4 turns!!!!!!

but the pump shop keeps telling me its not their pump thats causing the problem. :x

[Baixo]

i know that yout spent some $$ on the engine rebuild.....although it hurts....i would have to say send the pump to Giles.....

at least you know he does for the passion and will give you quality workmanship.

plus then you will be able to take full advantage of that sweet engine you have...

myself, i dont want to touch my pump. although im dying to modify im waiting to send my pump to Giles....its just something that i dont want to touch....

[burn_your_money]

and i was only able to turn my pump up about 1/2 a turn from where shop set it on main fueling, and now it will stay revving between shifts, and if u rev it out, will stay reved at the top, it didnt do this before the pump was built until it was turned up about 4 turns!!!!!!

Ok, so you had a problem with your pump, sent it out to a shop who rebuilt it for you to stock specs, but you had them change the shimming and advance spring?

You have your wastegate and overboost BOV thing disabled or set for 20psi?

I think you should retime it to 0.95, a fresh engine and fresh pump probably doesn't require as much advance.

[boosted_diesel_84]

and i was only able to turn my pump up about 1/2 a turn from where shop set it on main fueling, and now it will stay revving between shifts, and if u rev it out, will stay reved at the top, it didnt do this before the pump was built until it was turned up about 4 turns!!!!!!

Ok, so you had a problem with your pump, sent it out to a shop who rebuilt it for you to stock specs, but you had them change the shimming and advance spring?

You have your wastegate and overboost BOV thing disabled or set for 20psi?

I think you should retime it to 0.95, a fresh engine and fresh pump probably doesn't require as much advance.

i didnt really have a problem with the pump, it worked fine, just had 300,000 miles on it, and since everything else was gonna be new i figured i might as well have that redone.

the shop told me they did the shimming mod, and turned up the feed rate,  i also faxed them the instructions on how to do the govenor mod, but i dont know if they did that.

wastegate is completly blocked off, and it was redone when everything was rebuilt, and has a perfect seal, with the Passenger intake, there is no BOV.

with retarding my timing to .95 wont that hurt cold starting? and power and fuel mileage, i am getting around 46.5 mpg cruising around town staying out of boost as much as possible.

I would LOVE to have a Giles pump, but right now i just have the $1g to dump into it. but i was planning hopefully by summer to have it redone by him.

[8v-of-fury]

Sorry for digging this out of the swept away pile..

but is there anyway you could post up those instructions to the shim mod? I am looking to do this on my pump along with the Hallowed "Governor Mod"

thanks a lot.

[rabbitman]

Sorry for digging this out of the swept away pile..

but is there anyway you could post up those instructions to the shim mod? I am looking to do this on my pump along with the Hallowed "Governor Mod"

thanks a lot.

It's pretty simple to do, the problem is knowing if you helped anything.

On the front of the IP is a little cover held on by two screws, as you loosen the screws the spring inside will push the cover off (unless it's stuck). Under the cover is shim(s), a spring and maybe another shim on the other side of the spring.
You gotta leave a shim between the cover and spring or the cover might get machined, less shims will make it advance faster and more shim will make it advance slower.

Keep track of how many shims came out in case you wanna undo the mod. If you do it and can tell a difference let me know .

Oh yeah, fuel will come out of the cover so keep it off the rad hoses.......startup should be easy.

[8v-of-fury]

soo, if one were to find say a different spring of the same size.. yet softer compression.. and only use one shim on each side of the spring.. could one accomplish the best case scenario?

[rabbitman]

Just to nitpick for accuracy, the spring rate is what determines the rate of advance.  There are different colored springs that allow for different rates of advance.  The shims are what determine the initial pressure required for the dynamic advance to start advancing the timing. 

I see what you mean, the rate will stay the same but shouldn't a thicker shim make the spring get tighter sooner? Sooooo that would cause less overall advance........I'll have to think about this more.

[anto]

Libby should the internal pressure valve therefore be matched to the spring used in the advance mechanism to ensure the optimum advance at all rpm's? Or is it irrelevant provided the any internal pressure valve is set at the right pressure for that pump?

[vanbcguy]

The only thing in the pump that cares about internal pressure is the advance, so really they're both tune-ables.  The pressure valve will change the initial pressure and the rate of climb with RPM, while the spring and shims will change when advance starts and how far it moves with any given pressure.  All of that all depends on the engine and injectors that are being used too!

...and THIS is why we need people like Giles!!

[RadoTD]

One thing I've been wondering is if advancing the timing is good if I'm planning to put out bigger boost numbers.

I know that knocking obviously isn't an issue, but would it increase the stress on the rods and head if it were advanced beyond stock?

[truckinwagen]

I just got my hands on a fuel return stand from a MK2 diesel jetta.
I plan on making it into an adapter to fit a pressure gauge for setting internal pressure, and then making it available to borrow for the price of postage.

if we ever figure out what the best spring/internal pressure combo is, it could be useful to help set up our pumps right.

-Owen