Author Topic: Damage of a 12mm seized up..... (Read 10040 times)

Tintin · « **on:** February 19, 2007, 09:42:53 am »

That made the second times in less than one years that I seize up a 12mm in my M-TDI, The first time did not have too much damage inside the pump, but yesterday morning, I have to push the RPM a little too high... :oops: and here is the result: (20mm shaft)

I have to reassemble a pump, still 12mm, the car run again, but I do not dare to floor the accélérator for the moment :? ................

Slave2School · « **Reply #1 on:** February 19, 2007, 10:43:24 am »

Ouch, may I ask what RPM? So far so good for me but I don't hold high rpm since mine tries to get to the next higher gear as fast as it can...

RabbitGTDguy · « **Reply #2 on:** February 19, 2007, 01:30:00 pm »

No issues for me yet either....and I've pushed it up there a few times. Def...what RPM?

Joe

shadowmaker · « **Reply #3 on:** February 19, 2007, 02:26:32 pm »

I destroyed one pump completely few months ago too. Since been using some 2-stroke oil...

Slave2School · « **Reply #4 on:** February 19, 2007, 02:43:48 pm »

Yes I use 2 stroke oil in my pump with each fill up...hopefully that helps. Quick I need some wood to knock on!

Tintin · « **Reply #5 on:** February 19, 2007, 03:50:36 pm »

I use much 2 stroke oil, I have a fuel cooler, and I use an exit fitting with a larger flow, to have a faster circulation of fuel, (need a home made regulator) I wonder it's due to overheat or a mechanical breaking??

Approximately 3500rpm........ and the engine stopped..... :roll: they is curious, because I run at 4500rpm and more on several occasion without any problem.......

Slave2School · « **Reply #6 on:** February 19, 2007, 04:37:36 pm »

That is suprising to hear! Only 3500rpm

Maybe the unit you got had a flaw in it from the factory.

Tintin · « **Reply #7 on:** February 19, 2007, 04:46:36 pm »

I have approximately 7000KM on it, and I him board makes undergo much torture :lol: Is necessary to know that it is not conceived for so high RPM range, it goes a time, but that ended up breaking.

RabbitGTDguy · « **Reply #8 on:** February 20, 2007, 04:49:56 am »

was it a Bosch made pump head, or one of the many others I've seen for sale recently new? I've heard stories about them seizing, etc. Haven't heard of many issues with the Bosch 12mm heads as long as you don't hold 4k + rpm on it...

Joe

SMOKEYDUB · « **Reply #9 on:** February 20, 2007, 06:31:13 am »

is it just to much pressure on it and its just shearing or is it actually siezing. I would think that it would more likely shear do to higher pressures right?

Tintin · « **Reply #10 on:** February 20, 2007, 07:11:43 am »

Quote from: "Named Tintin"

Approximately 3500rpm........ and the engine stopped..... :roll: they is curious, because I run at 4500rpm and more on several occasion without any problem.......

That it is really bizzare...... I suspect that the foot of the plungor ended up cracking because of too high RPM, therefore, the plungor has sudden side force, that have to overheat and seized up.

I have tendency has to believe it, since the pine in the came plate did not break, and the quantity of metal crushed in this section carries me has to believe that the pump worked 5-10sec before seized up, normally when a plungor seizes up, the pine is one of the first thing to be broken, and there is not much crushed metal.

SMOKEYDUB · « **Reply #11 on:** February 21, 2007, 12:27:00 pm »

i also have a 12mm pump. I plan on autocrossing my rabbit once in a while and i am wondering would the pump just explode if i did that? Is the pump exploding the only problems that people are having with the tdim? and i may have mentioned this before but can we lower the injection presure of the nozzles or what? maybe it will be easier on the pump.

therabbittree · « **Reply #12 on:** March 28, 2007, 07:06:09 am »

the pump won't explode... it will just not work any more...it teh gear may spin but it won't pump any more fuel. i've only used real bosch 12mm pumps and I had 2 12mm pumps seize up on me ..the second one just happened to my friend. I sold him my tdi m..argh and as you can imagine he doesn't know how to fix it so I have to go and fix it for him..I told him to send it to Giles
thanks
Deo

lord_verminaard · « **Reply #13 on:** March 28, 2007, 07:34:42 am »

In one of my conversations with a local Diesel shop, they told me a guy was running a huge pump in a VW diesel, and he seized it up because the pump was putting out way more fuel than the injectors could handle, effectively causing "backpressure" in the pump. Sounds logical to me, is it possible?

Brendan
84 Scirocco 8v <-- TDI in progress
01 Jeep TJ 4.0

therabbittree · « **Reply #14 on:** March 28, 2007, 07:38:06 am »

yes its possible..you should run the big nozzles..i was running teh race 520.'s the .260 size ones and it lasted longer.. i sold my tdi m with eth 216 nozzles and it lasted not too long at all argh... you need a extr alift pumptosafetly run these pumps..they need alot of fuel pressure..ie 20psi before the load..at it will pull down ..no less then 5 psi pre pump fuel pressureor your pump will overheat, score and make metal...