Breakaway944

Has anyone used aftermarket Sierra Cosworth injectors? I am chasing down a stumbling problem in my car and I want to eliminate the fuel injectors as a problem. My injectors were redone by Witch Hunter about 2k miles and 3 years ago. I just did a lot of re wiring and got a stumbling problem. I want to eliminate the possibility that I damaged an injectors during the wiring process (manifold came off). I was going to send the injectors back out, or take them to a place here, but if i can get new injectors to test for the same price...Anyway the Sierra uses the same injectors as the 951 and there are some people making them. They seem to have an updated 4 nozzle tip, but seem the same otherwise. Anyone have experience with them? Is the 4 nozzle better?
Thanks for your thoughts

H.F.B.

4 nozzle injectors are always better. But I wouldn't change OEM injectors for 4 nozzles injectors, when running a stock DME.
I'm running Volvo injectors in my 944, but with VEMS. 4 hole. This means better fuel atomization, so better cold start, idle, part throttle behaviour, fuel economy and driveability. With the 4 hole injectors I could reduce VEMS start, afterstart and warmup enrichment settings significantly.
https://rennlist.com/forums/924-931-...l#post16285387

Breakaway944

I have been through dozens of threads of BMW and Porsche (NA) owners upgrading to 4 hole injectors with no problems, no programming and only good reviews. These people were all running stock DME. The claim being the DME is able to adjust fuel flow 10ish% to compensate for various conditions. IE, a car with 100k miles on it with worn injectors, worn cap and rotor, worn spark plugs etc will still run without needing to reprogram the DME. The only people that need to reprogram that I have run across are upgrading to higher flow injectors, this is a no brainer - but not what we are talking about. I was wondering if you can expand on why you needed so much programming just by going 4 hole and nothing else. Is everyone destroying their cars? Does VEMS adjust things automatically like the stock DME or does it only do what you tell it?
Fuel injection is one of the biggest disappointments in the auto industry I have learned about.

Am I the only person to consider aftermarket injectors (stock, not higher flow) for a turbo? There are also aftermarket one hole injectors, would these be a better bet?

H.F.B.

👆🙂☝️¯\_(ツ)_/¯

Nowanker

Not to stray too far off topic, but IMO, electronic fuel injection is the best thing to happen to internal combustion ever. 2nd best thing is electronic spark control...
Carburetors and distributors are simpler, but fall short in sooooo many ways.
Back to the real topic...
I can see how an injector with the same flow rate but better atomization would provide more burnable fuel and cause a rich condition. Hard for me to imagine it would be enough to require a retune, but maybe.
Flow rate isn't the only measurement of an injector. Different injectors have different response times from off to on. Dunno if that will be a factor, but it might show up at light load operation.
Last one is injector quality. Lots of crap on the market these days. If it's not a name brand (Bosch, Delphi, etc...) and from a reputable vendor, I'd walk away.
Last thing you need are injectors that don't all flow the same rate. 1 cylinder running too lean, others a little rich: Looks good on the AFR monitor, but burned piston under load.

Breakaway944

This is the main thing I worry about. Some parts from some "reputable" vendors are not that great, much less no reputation places! Most of the time I would prefer a used OE part over a new aftermarket part. I have already had the injectors done by Witchhunter but they are still 37 years old. At that age things get brittle and unreliable. I am having a misfire right now so will be using these to diagnose the issue. There are so few cars that use this injector, the Fords being the only ones I found, that no major manufacturer would think to make aftermarket pieces. So we are left with smaller places to deal with if we choose. I ordered a set and will check the resistance and flow to make sure they are in spec. If the injectors are not my problem I will reinstall the OE ones.

You are correct in regards to modern injection, it finally delivers on the original promise. Fuel injection was sold as "a computer controlled fuel system that injects fuel into each cylinder at the precise time and by using an O2 sensor that is checked 80 trillion times a second to adjust the pulse of the injection to provide the perfect a/f ratio all the time!" So the first time I heard the phrase "multi port injection" I thought why would they brag about a standard feature? Then I heard the phrase "sequential" and thought "of course it is sequential. Who would be stupid enough to fire injectors in a batch?"
I had a Starion ESIR that embodied everything wrong with FI. I forget, but it had one or two injectors at the throttle body continuously injecting fuel. Barley a step up from a carb. Actually it could be a step down because I had to replace the injector twice because of severe fire inducing leaks. I say "could" because even though I LOVED this car (who does not like box flares!) it was a complete POS so if it did have carbs they probably would have gone bad too!

Nowanker

EFI has come a long way...