I've an 88 gti with yellow injectors. I've also bought a used set of injectors and I was out tinkering this afternoon and I've only just noticed that my 2nd set of injectors is blue. I've done a search and I think that the blue injectors are of a later design and maybe a bit better (4 holes plays 1 hole??) Given this I don't think I can mix and match injectors between yellow and blue (which was my original plan - ie pick the best 4 from 8). But could I switch from yellow to blue? ie is there a difference in fueling between the two, or is a straight swap possible without also swapping ECU and AFM?? Or do I now need to look for yellow injectors out in ebayland?
I had issues mapping a Polo on idle running quad-pintle style injectors, whereas it was fine on single pintles with the same flow rate. The spray pattern on the quad-pintles was totally different (but correct to spec for those injectors), and was spraying the inlet runner walls with fuel rather than down the port and atomising nicely. It did a good job of filling the sump with petrol! Having said all that, the Polo was designed with single pintle injectors, so it may just be that particular application that it caused problems with. Both sets of injectors were Bosch, but the quad-pintles were not from a VW application. If both your sets of injectors are from the same type/year of engine I'd imagine they'll be fine!
Volkswagen MK2 digifant = 191.8cc/min, Bosch 0 280 150 757, VW 037 906 031A Volkswagen MK2 digifant = 197cc/min, Bosch 0 280 150 903 Volkswagen MK2 digifant = 197 or 218.1cc/min?, Bosch 0 280 150 902, VW 037 906 031C as you can see, bugger all in it really
Quad Pintle or Disc w/multi holes? EV1 vs EV6/12? Thought the EV1 series was just a single pintle. The digifant injectors fitted to PB/PF engines where EV1 (pintle) units. What you said about wall wetting and the use of the multihole injectors in 2v/cyl engine is valid . In this case the design of the 0280150902/903 and 757 OE pintle units for a PB/PF engine should have the same effect from a spray efficiency and fuel atomisation point of veiw with the correct fuel delivery pressure.
Single pintle, but disc with multiple (4) holes - EV1 body like G60 "greens", though no plastic pintle cap on the end. Spray pattern is clearly different to the recommended G60 injectors when you stick it on an ASNU machine. They'd been sold to the customer as an alternative to G60 injectors - flow rate was okay, as was impedance, but the spray pattern was just wrong for the application. It was a high CR turbo'd application too, so didn't need much fuel at idle. I know others use the same multiple-hole injectors on the 2v/cylinder Polo engines without issue - but they're on 8.0:1 compression PY code engines, not 9.5:1 AAV lumps.
