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Modern fuel injectors

J

James0

Member
Evening all. As per the title, does anyone have experience of using EV6 fuel injectors on a 944? Some googling suggests they mostly don‘t have the groove for the clip on the fuel rail. There was talk of dremeling a slot in the injector, which sounds sketchy at best.
Being as I’m going to need to adjust the mapping with the different turbo, ultimately visiting a dyno again.
I might as well replace the ancient originals With some nice new high impedance units.
 
I'd be careful where you buy them from, there are knock off injectors on ebay etc.
 
It does seem a bit of a minefield. Not a part I’d want to be unreliable. Might have to get some bottles, run the injector test mode and see what the originals are like.

 
You'll be fine if you buy from an authorised dealer, with plenty of feedback. Obviously you know, with 3.0 and a bigger turbo you may not have much headroom on standard injectors, unless you're conservative with the boost. Time to machine the pistons?
 
The boost will stay on the sensible side. Its never been about max power for me. I think more modern injectors would be a better mod than wasted spark for example. Its just making sure they physically fit.

 
well, I've fitted the K27/8, removed the venturi, replaced lots of hoses, fitted a check valve to the AOS line also re plumbed the boost control solenoid.

Cleaned the engine, made a new turbo heat shield, forgot to tighten the turbo oil feed. Pumped 2 litres of oil over clean engine and driveway....

Cleaned that up.

Went for a spin on wastegate only. all good. Spent ages trying to get boost control working, till I realised it was arse about face.
Boost cut set to 14.5 psi (1 bar) and aimed for 12psi as with the k26.
Once boost control was working, I took some logs and at 12.8 psi, 4444 revs (as far as I went with one eye on AFRs) the stock injectors are at 94% duty cycle and the AFR was at 12.5, so a little lean.
Obviously its running into different parts of the fuel map.
Its running better, fairly rapid and I think cooler but yes, going to need bigger injectors, even at 12psi.
 
Are you using a 3 bar, or adjustable fuel pressure regulator. And is your fuel pump in good condition?
 
Hi Paul, yeah fixed at 3 bar. I’ve tested the original injectors and they produced identical amounts of fuel each over different revs (noisy things without the engine running). I must admit I didn't calculate flow, just compared them.

I think the pump is ok. I guess I could put a gauge on the rail, I bet it’s a bloody awkward metric thread though.
 
It occurred to me that the injector specs were probably estimated when it was mapped years ago so they may not be as near the limit. Either way I've ordered some Bosch 0280158123 injectors, they'll need adaptors but not the end of the world.
 
I couldn’t find a lot of info on what others had used.
Yes the Siemens would be a direct fit. I went back and forth on this and the Bosch injectors seemed to be the best option that were in stock in the sort of flow rate I wanted. They’re OEM on 911 turbos.
 
I’ve got the 870cc ones and have no issues with idle or low load areas, they do do a 630cc version I believe.


Sounds like the Bosch ones fit the bill too though.
 
If only you pair had spoken up earlier...:ROFLMAO:
Nothing like going against the flow.


I may or may not put this in my car. Annoyingly to remove the Vems Wideband, I have to un pin the plug to the sensor and pull it back through bulkhead to take it out of the mount.
dateposted-public


https://www.flickr.com/ph.../in/dateposted-public/
If the pic didn't work, it's a small screen with a raspberry pi showing some guages
 
Sorry, must have missed the post.


I hadn’t realised you were on VEMS too, if so I’d have further confounded things by saying that VEMS with drive both high and low impedance injectors so it makes the choice even wider [:-]

Why would you have to remove the wideband to fit the gauge screen? (I ran my wideband cable under the gear lever foam and under the car that way so I didn’t have to depin the connector). I bought an Android Head Unit and downloaded the VEMSDisplay app.
 
Just joking, its more interesting doing things differently anyway.

I'm running a Microsquirt but just happen to have a Vems Round Wideband unit. The Wideband has a surprisingly large number of features, including boost control and EGT sensor.

Wish I'd thought of running the cables through the gear lever, rather than through the bulkhead.

I've got a Raspberry pi running Tuner Studio, connected to a small HDMI screen that would take the place of the gauges under the radio (except the AFR), but frankly its overkill when I can see all the gauges on an Android mobile or Stereo.
Kind of a project for the sake of it, as I got one for Christmas.

 
So, I fitted the new injectors, updated the settings and ditched the ballast resistors.

It started first go, running rich in the elevens. Ended up dialing back the VE table by 28%, which seems about right.

However idle is awful, can't get it steady at 14-1, like I could before. I think it's because the o-rings are 14.5mm and older Bosch 15mm and maybe not sealing well against the manifold.So ordered new o-rings.

Currently the extended nozzle pokes quite far into the inlet. I'll also try it with the adapter on the nozzle end so it's like a conventional injector, see if that he helps.
Oh well off to race mountain bikes in the peeing rain now.

 
Morning James, 14.1 is a little rich, try and get it closer to 14.7 for both idle and cruising. The car will run better and give more power too. Then check what it is at WOT to ensure it's getting enough fuel.

Pete
 
From what I've read, you need quite an expensive sniffer setup for that level of accuracy. Not sure the gauges in £150 kits constantly give that?
 
Morning, guys.
My engine has never liked idling at what my wideband reads as 14.7. Its much happier a little richer.
It may also be the modern injector Is designed for 4 valve heads and is spraying in a less than ideal Pattern. Looks like I'll have to drink another 4 bottles of beer for flow test containers and see what the Pattern/delta looks like.
The injectors came in genuine boxes and the codes checked out.
I'll have a play again when the o-rings turn up. They may just not be suitable.

 
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