fbgh2o

Will be removing the fuel rail and intake and figured maybe I would have injectors cleaned at the same time.

Can someone please tell me what it means to have them "flow matched" and what the benefit of same is?

Also, for you Canadians, since Witchhunter won't ship to Canada, who do you recommend...

Thanks

theedge

They get put in a machine that measures exactly how much each injector flows through it when its open for a specific amount of time. Flow matched means each one flows nearly the same amount, so you dont have one injector that flows 10% less when it is open for 2 milliseconds than the others flow when theyre open for 2 milliseconds. The cylinder with that injector would be running leaner than the others. I dont think you can modify injectors to adjust their flow, all they can do is test several sets of injectors and match them up so they are similar.

I had a set cleaned and tested by this shop and I was happy. Theyre in Port Kells BC tho (5 minutes from me). You could call local performance diesel shops or tuner shops and see if there is something similar near you.

http://www.nwfuel.ca/

INURGRL951

Flow matching is very important if you want a good even burn across all for cylinders. It's is most important on a modded engine with higher boost when it comes into play into getting a decent tune file.

So if it a fairly stock motor I don't see that being necessary

But in just makes it more efficient an un-match set usually run about 8-12% off of the set of four but a match set usually run within 2-6% of the set.

costas

951Saga

My set from WitchHunter came back balanced at 1.3%. In which cylinders should I put the two lower flowing injectors? TIA

- Jason

sebastian944

Be careful taking the manifold and fuel rail off. I think my last mechanic blew my DME that way. Car was fine before i had front engine work done. By the way are you still going to 944fest?

reno808

take the one that flows the most and put in number 4

fbgh2o

I am not sure how you think the fuel rail and intake removal are related to the DME. Can you expand?

I always disconnect the battery before doing anything on the car to avoid any electrical issues and when working with fuel (spark and fuel vapour are a bad combo).

50:50 right now for the fest. Depends on work.

JJK78

A good injector cleaning is never a bad idea. I just sent mine off to injectorrx.com who is in Texas, not sure if they ship to Canada but i heard good things. You could also try RC Engineering, a bit more expensive but another option to check out.

951Saga

Thanks reno I don't have to pull the rail again.
By chance I installed them in order as tested and #4 has the highest flow numbers.
This should have been the first service completed when I bought the car almost five years ago. It's never run so well.

sebastian944

That's what I said. I don't know how the DME was damaged after doing belts\rollers\WP\vacuum lines\turbo oil feed O-Ring. I even had my battery disconnected after i dropped it off. Unless the DME was already on it's last legs and it was just coincidence. Then again, i haven't confirmed my DME is damaged. If the intake manifold was taken off then the MAF was also taken off so there might also be a problem with the MAF. All I'm saying is once you start taking things off it's possible something else might fail.

..And a trained Porsche Mechanic did this work.

Chris White

Try Markus Blaszak - a good 944 Porsche shop in Canada that does cleaning and flowing.
As far as the failed DME - best guess would be that the brittle insulation on the fuel injector wires broke and an injector shorted out. You can't really blame the mechanic - impossible to see and any movement at all can cause an old harness to fail.

sebastian944

My mechanic did notice several breaks/repairs to the injector harness, but they still suspect the DME in my case because there is a good signal to the injectors.

marky522

If he is checking with a noid light, it still doesnt rule out the harness, just because a signal is making it to the connector doesnt mean that it can carry required current.

Mark

sebastian944

Yeah i figured that. They don't have an oscilloscope when i asked about it. That is really frustrating when your paying their labour rate and they don't have the proper tools.

sebastian944

If there was a break in the injector harness, there would have to be a break for all four cylinders for the car not to start though right?