7A replacement bosch injectors discussion

[Tun]

Looking at changing the injectors my 7a, how are you getting on with the pink bosch injector?

[PoloGaz]

It all seems fine. Must admit I've not had it checked on a dyno or anything but it starts well, runs smooth and sounds lovely. I'm getting low 30s on a run. Expected a little more but I've a heavy right foot and the cars not exactly aerodynamic

On paper they are the same as the greys apart from slightly lower impedance (closer to, but still higher than that of the original low impedance injector+resistor pack combo)

I'm having the car dynoed at the end of Jan at a club rolling road day (in association with club polo) so should have some info from that.

[Colin Aitchison]

Hi PoloGaz, Keep up the good work about the fuel injector upgrade, My audi coupe conversion to 20v 7a engine now has a youtube video, see and hear it at "B2 Audi coupe GT 20v 7A conversion first drive"
I would also like to change the standard injectors to Bosch injectors but which ones do you go for, as you have posted there is some conflicting information out there on the internet.

[PoloGaz]

If you have any doubts go for the greys I guess? I think my manfold has provision for a second lambda, perhaps I should invest in a wideband

I have a spare pink injector - if anyone has a spare grey id be willing to have them compared at an injector cleaning place

[PoloGaz]

Haven't been on here for a while, but here's a rolling road print out of the engine in my passat with the pink injectors, stainless exhaust and piper cams



I think I was maybe expecting a bit more from it - wouldn't necessarily put it down to the injectors though as it's not mapped for the cams AFAIK (was Error404's engine)

[4v6]

I used to work for Aldon many years ago.

[PoloGaz]

Update on this

Been running the pinks for a few years now no problem. I think for a stock 7a they do the job

I can’t help but feel that there is more to give from my engine. So I decided to have a look around for some bigger injectors

The 034 kits started coming with Bosch 0280155831 brown/orange injectors. I’ve managed to find out a few things about these

Again they are Volvo injectors, fitted to 5 and 6 cylinder turbocharged engines. 320cc They are a newer version of 0280155759 fitter to earlier Volvo turbos. They are the same flow rate but have a twin cone spray pattern. The 759s spray a single cone. I would think the twin cone was developed for better performance in multi valve heads, though the Volvo’s in question were always multi valve! (I guess Bosch hadn’t developed them yet)

The ones I have now 0280155832s Will more than likely be for sale if anyone is interested! They’re 250cc, dual cone

The 831s are readily available. I’ve just bought some 2nd hand for £40 on eBay I’ll get injectortune to service them. I’m going back to aldon next month, so it’ll be interesting to see what a difference it makes

[Davids]

Originally Posted by PoloGaz

Update on this

Been running the pinks for a few years now no problem. I think for a stock 7a they do the job

I can’t help but feel that there is more to give from my engine. So I decided to have a look around for some bigger injectors

The 034 kits started coming with Bosch 0280155831 brown/orange injectors. I’ve managed to find out a few things about these

Again they are Volvo injectors, fitted to 5 and 6 cylinder turbocharged engines. 320cc They are a newer version of 0280155759 fitter to earlier Volvo turbos. They are the same flow rate but have a twin cone spray pattern. The 759s spray a single cone. I would think the twin cone was developed for better performance in multi valve heads, though the Volvo’s in question were always multi valve! (I guess Bosch hadn’t developed them yet)

The ones I have now 0280155832s Will more than likely be for sale if anyone is interested! They’re 250cc, dual cone

The 831s are readily available. I’ve just bought some 2nd hand for £40 on eBay I’ll get injectortune to service them. I’m going back to aldon next month, so it’ll be interesting to see what a difference it makes

Hi, been reading your thread with interest as I am looking at replacing my injectors as well overt the next few months. The Bosch 0280155831 look the best bet so I will be going for these, but I cant work out, did you mod the resistor pack like the 034 kit ? or did you leave the resistor pack as OE and Audi built it from factory ?

Thanks for the write up on this, been real helpful, just the resistor pack issue now to sort out.

Cheers

David

[mikes2]

The resistor pack needs bypassed if you are using Bosch injectors. Easiest way is to buy replacement connectors and run a small loom of 3 wires joined together in place of the resistor pack.

I ran the Volvo brown injectors for a while. Think they're rated at 305cc @ 3 bar. The car ran far too rich.

I got the grey ones overhauled by Mr Injector and switched back

[Davids]

Originally Posted by mikes2

The resistor pack needs bypassed if you are using Bosch injectors. Easiest way is to buy replacement connectors and run a small loom of 3 wires joined together in place of the resistor pack.

I ran the Volvo brown injectors for a while. Think they're rated at 305cc @ 3 bar. The car ran far too rich.

I got the grey ones overhauled by Mr Injector and switched back

Thanks for the tip, Grey ones part No 0280155931, will be used then.
I know I can look on the parts list but do you happen to know off hand what the part number of the 2 plugs for the resistor pack might be please, I would rather go this route than cut and crimp, as the car is totally original, abet wanting some work.

Cheers
David