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more injector woes
ned - 4/4/06 at 09:45 AM

the saga so far:

yonks back i posted about injectors, ended up buying some new bosch 803's (cossie greens) but i have recently been told (by the rolling road i plan to use) they are the wrong impedence for my ecu and will fry my ecu drivers and that ballast reisistors will delay the timing on them so advised against using them.

So the other week (i was given a list of suitable injectors by the chap at the rolling road) i ordered some recon bosch 756's (high impedence, similar flow rate as used on a turbocharged gm truck!) these arrived but one of them seems damaged (see pic)
I have tried contacting the people in the states where i got them, first last weds and again on friday (early in the day bearing in mind the time difference first thing before they're up) and have heard nothing.

Now I'm thinking I'll have to do a chargeback on my card but I still need a set of suitable injectors.

Does anyone know of somewhere in the UK that I can get bosch injectors from? BTW the place in the states had been recommended by a member on this site who'd bought from them without problems.

cheers,

Ned. Rescued attachment IMG_1932b.jpg
Rescued attachment IMG_1932b.jpg


James - 4/4/06 at 10:38 AM

Cost me a bloody fortune to get the Postman to knacker that injector!






[Edited on 4/4/06 by James]


ned - 4/4/06 at 10:49 AM

shut up bitch

ps why do you think i sabotaged your m/c when you weren't looking!!

[Edited on 4/4/06 by ned]


James - 4/4/06 at 10:56 AM

quote:
Originally posted by ned
shut up bitch

ps why do you think i sabotaged your m/c when you weren't looking!!

[Edited on 4/4/06 by ned]



And was it you that intercepted the delivery of the rebuild kit, swapped half the parts for ones I don't recognise and made most of the others not fit as well!

Hot damn.... you good.....


Mix - 4/4/06 at 11:04 AM

The damaged part looks like the plastic cap, you can prise these off if you're careful, a trip to the scrappy may be in order, they are just a push fit.

Mick


ned - 4/4/06 at 11:06 AM

Mick,

Yes it does just seem to be the plastic cap, obviously i don't want to have that facing into my engine for fear of it falling off - though unlikely i know.

this pic is quite handy: http://www.injectorservices.com/injectcut.htm

[Edited on 4/4/06 by ned]


NS Dev - 4/4/06 at 11:11 AM

find a fuel specialist that does the "asnu" injector service, they will have replacement caps.


Mix - 4/4/06 at 11:12 AM

Yep the second pic confirms it. Just find something with bosch injectors in a scrappy.

Mick


britishtrident - 4/4/06 at 11:26 AM

What sort of power will your engine produce I have a few set of injectors around,

A set off a Honda engined Rover 623 (158 bhp)
and a set from a Rover 800 Turbo (170-180 bhp). I also have smaller ones.


ned - 4/4/06 at 11:29 AM

the injectors i have are 295cc/min @ 3 bar. looking at around 210-220bhp to start off with, but potential to go solid lifters and cams upto around 260 with some head work.

Ned.


BKLOCO - 4/4/06 at 12:15 PM

Well I'm F***ed if I can understand how balast resistors are going to delay the timing of the ingectors and even if they do it will not matter.
The delay will allways be the same so the map will compensate for it.
I think you are being told rubbish here.
If you think about it logically the timing of the injectors really doesn't matter...the fuel will still be in the inlet tract for the next stroke. When you tune the map you just tune the injector pulse duration not the timing within the cycle. The more I think about this the more I think your road op is talking b0ll0cks.


NS Dev - 4/4/06 at 12:15 PM

thinking about it Ned, just bin the cap! The std bosch cream injectors don't have them fitted on anyway


BKLOCO - 4/4/06 at 12:22 PM

Thinking about this further and talking with collegues the concensus seems to be if the roller op knows this little about fuel inj you may be better going elsewhere.
Always remember:
"Any piece of equipment is only as good as the opperator"


MikeRJ - 4/4/06 at 12:27 PM

quote:
Originally posted by BKLOCO
Well I'm F***ed if I can understand how balast resistors are going to delay the timing of the ingectors and even if they do it will not matter.
The delay will allways be the same so the map will compensate for it.
I think you are being told rubbish here.



What he has been told has a sound basis. Resistors slow the rise time of the injector current, and make the injectors open more slowly. Slow opening injectors makes calibration at low flow rates tricky, especialy when you have high flow injectors, and increases the minimum useable injector pulse width. This means idle quality and part throttle response can be compromised.

This is the whole point of low impedance injectors, the current rise time (and hence opening time) is greatly improved, but you need a scheme to limit current (usualy PWM). Adding ballast resistors defeats the whole point of the low impedance injectors.


BKLOCO - 4/4/06 at 12:33 PM

quote:
Originally posted by MikeRJ


What he has been told has a sound basis. Resistors slow the rise time of the injector current, and make the injectors open more slowly. Slow opening injectors makes calibration at low flow rates tricky, especialy when you have high flow injectors, and increases the minimum useable injector pulse width. This means idle quality and part throttle response can be compromised.

This is the whole point of low impedance injectors, the current rise time (and hence opening time) is greatly improved, but you need a scheme to limit current (usualy PWM). Adding ballast resistors defeats the whole point of the low impedance injectors.



I fully understand all of this but there is generally a parameter to compensate for the opening time of the injectors.
Besides he is now talking about fitting high impedance injectors anyway so the "speed" advantage of the low impedance ones doesn't matter.


MikeRJ - 4/4/06 at 12:36 PM

I agree that it will probably work ok with ballast resistors, just saying that there is some truth in what he's been told.


ned - 4/4/06 at 01:15 PM

MikeRJ's explanation is basically what I was told, and I believe that its the nicer way to do it. The rolling road in question is Track & Road Powerformance and it was Steve Pischer that I spoke to (Steve Greenauld is the other guy there) and they always seem to be highly recommended by the westfield and caterham owners.

Ned.


britishtrident - 4/4/06 at 02:08 PM

Oh 3 inch drain pipe for fuel lines :-)