To upgrade injectors or not...

[amdaidan64]

2001 Golf, replaced the turbo a few months ago with a VNT17, and car is stock other than this and a disables EGR system.

I was getting over boost problems as I previously talked about but I think this was caused by the ECU compensating for the poor performance of the turbo that was on it because I don't get the over boost anymore and it still works great.

I now have what I suspect to be a bad injector (knocking-ish sound at certain throttle positions) so i am wondering if I should replace the stock injectors for a performance increase or just keep them the same and replace the bad one.

On a side note how can I figure out which one is bad?

 

[Nero Morg]

If it knocks at idle, crack one injector, see if it stops. If it doesn't, tighten it and move to the next.

Essentially you're disabling the injectors one at a time to isolate it.
Mind you, it'll make a mess. It's how we diagnose old mechanical ISB's and such

 

[amdaidan64]

Might give this a try, was looking at replacement injectors and it looks like the ALH uses a special tool to fit on the injectors, know if this is the case?

 

[Nero Morg]

It definitely isn't the case. Can be done with a basic wrench set

 

[amdaidan64]

Perfect, thanks!

 

[PakProtector]

A word of caution: The IP is quite capable of driving fuel into you as efficiently as a needle. A high pressure spray is not what your skin evolved to tolerate.
cheers,
Douglas

 

[Nero Morg]

Also yes. Be careful, keep hands clear and wear gloves. Hydraulic injection wounds are no joke.

 

[2002_auto_tdi]

Not to hijack, but these last two posts scare me. I knew a Ford mechanic who would only work on gasser Excursions because of a similar possibility. I have been asking others about this phenomenon for years and all that I get are blank stares. I just hit google on this and the responses were very general but not positive. Could anyone expand? I'd like to add this to my list of precautions now.

Thanks.

 

[amdaidan64]

My interpretation of his instructions were to simply loosen the injector not totally take it out, is this wrong?

 

[Nero Morg]

You loosen the fuel supply line to the injector at the injector, not the hold down clamp. And it's literally like 1/4 of a turn, if not less. Yes, it'll spray diesel upwards, but it's a trick diesel mechanics have been using on VE style fuel systems for years. Matter of fact, if you don't do it on a dodge 5.9 to bleed the air out of the fuel, you have a high probability of blowing up the fuel pump.

It's more intimidating than it actually is. Really shows experience of some people you see on google, because the powerstroke excursions use hydraulic electric fuel injectors, and you have to take the valve covers off to get to them anyways. No way fuel can spray you.

Now common rail... That's another fun story... Upwards of 30,000psi stored in a little tube....

 

[PakProtector]

The instructions were to loosen the 17mm nut that attaches the line to the injector body. This leaves a non-zero chance of delivering a spray of high velocity diesel fuel right through your skin due to the leak created by loosening the nut. It is far less likely than sticking yourself in the injector's delivery plume if it is outside the head.
cheers,
Douglas

 

[KrashDH]

You loosen the fuel supply line to the injector at the injector, not the hold down clamp. And it's literally like 1/4 of a turn, if not less. Yes, it'll spray diesel upwards, but it's a trick diesel mechanics have been using on VE style fuel systems for years. Matter of fact, if you don't do it on a dodge 5.9 to bleed the air out of the fuel, you have a high probability of blowing up the fuel pump.

It's more intimidating than it actually is. Really shows experience of some people you see on google, because the powerstroke excursions use hydraulic electric fuel injectors, and you have to take the valve covers off to get to them anyways. No way fuel can spray you.

Now common rail... That's another fun story... Upwards of 30,000psi stored in a little tube....

What 5.9 are you talking about? My late 04 there is no cracking of the injector lines to bleed the system. I have a dual filter setup I built that's mounted on the rail. When I change those filters, I pre fill. The only thing I have to do to prime/bleed the system is bump the key 5 or 6 times and let the pump run for about 30 seconds. It's a self purging system. A few weeks back I replaced my injector #4 high pressure line with the superseded part number because the original designing was failing and leading to cracked lines. Mine wasn't doing that but I wanted to get ahead of it. There is a quick pressure relief process you follow by pulling the fuel relay, starting the truck, then letting it die. Then you are good to go to work on all high pressure stuff.

I think cracking the lines was for 2nd gen and earlier with the VP pumps.

 

[Nero Morg]

You are correct, the vp5.9.

 

[amdaidan64]

You loosen the fuel supply line to the injector at the injector, not the hold down clamp. And it's literally like 1/4 of a turn, if not less. Yes, it'll spray diesel upwards, but it's a trick diesel mechanics have been using on VE style fuel systems for years. Matter of fact, if you don't do it on a dodge 5.9 to bleed the air out of the fuel, you have a high probability of blowing up the fuel pump.

It's more intimidating than it actually is. Really shows experience of some people you see on google, because the powerstroke excursions use hydraulic electric fuel injectors, and you have to take the valve covers off to get to them anyways. No way fuel can spray you.

Now common rail... That's another fun story... Upwards of 30,000psi stored in a little tube....

Ahh the supply line, I was thinking the injector itself