Author Topic: How to rebuild injector correctly???? (Read 10794 times)

ricosuave · « **Reply #15 on:** February 18, 2006, 10:59:33 am »

anyone willing to test/sell in the calgary area?

jantd · « **Reply #16 on:** February 18, 2006, 11:10:25 am »

Just read it ,it's in a mail of libbybapa,january 12 2006
Jan

TDForNow · « **Reply #17 on:** February 18, 2006, 10:54:26 pm »

LOL! Libbybapa, you're right, 100 bar IS a lot! Sorry 'bout that, I meant to ask about 10 bar intervals (10 bar = 140 psi, right?)

Master ACiD · « **Reply #18 on:** February 18, 2006, 11:06:51 pm »

i think its 147 at sea level, or something like that.

DieselMonkey · « **Reply #19 on:** February 19, 2006, 07:37:52 am »

Guys,

On the topic of raising breaking pressure, the TDi's breaking pressure is 190 / 300 bar on the 90 bhp 1Z engine. They also use the same timing belt and tensioner etc... as the D and TD's. So for this reason, I wouldnt worry too much about the effect on the timing belt. They do however have an additional roller tensioner just above the fuel pump pully.

Whats the highest anyone has attempted to run with shimmed injectors ? Mine are set at 165 bar and the engine pulls strong.

What experiences has anyone else had with higher breaking pressure ?

I've always felt that each time I had them raised in pressure, the engine ran and pulled better with reduced smoke.

Master ACiD · « **Reply #20 on:** February 19, 2006, 10:15:54 am »

if it is true that increased breaking pressure results in less smoke, better starts, better economy etc, then why didnt vw use turbo injector breaking pressure in every diesel? or why stop at 155 bar, why didnt vw just make every injector 200 bar across all platforms?

surely vw would not leave something as obvious as this out of the equasion when the little 1.5 and 1.6D guys are struggling to get over the next hill?

TDForNow · « **Reply #21 on:** February 19, 2006, 03:10:52 pm »

Exactly! What IS the con to using increased breaking pressures? Is it the IDI's pre-chamber that's the restriction (both figuratively and literally) as in impeding (what I would suspect would be) the hotter and faster flame front? Where-as the TDI's ignition is already in the cylinder.

vwmike · « **Reply #22 on:** February 19, 2006, 04:40:06 pm »

You're comparing too different types of nozzles here. Increasing pop pressure will slightly retard timing and deliver slightly less fuel. There will be increased pintle chatter which is what atomizes the fuel. If the injectors just held themselves open you'd get nothing but a stream of fuel not unlike a fire hose.

Like everything there are compromises. If VW were to increase the breaking pressure they may have to reduce the timing belt interval and injection pumps may not last as long. Not to mention this will result in additional parasitic losses due to the increased energy drawn by the pump. So the question you have to ask is whether or not the slight increse in economy is worth sacrificing pump longevity and whether or not it outweighs the losses felt by working the pump harder.