Just installed 550cc injectors on the crossfire, and when we turned it on it has a rough idle, after a while it smoothens out and stops. But then you can smell how rich the car is just standing still, even more when driving behind it. I thought this was the battery, since when we finished the install the battery was almost dead, but we charged it while we downloaded the new tune, next day got a new battery in, still the rough cold starts. once it was warm, I can drive it along just fine, but next morning, same issue. Got a check engine light and codes about cylinder 1 misfire and injector problems, on my way to scan it, it went into limp mode, and had to pull over, turn it off and on, and everything back to normal. Even when warm, again having misfires. Now we double checked the injectors, since eurocharged insisted it be the install, and even after double checking its the same. Rough cold starts and after its warm, its all good. I sent cold start datalog to them, but haven't heard back. Its been 2 weeks of frustrations.

 

How, or why did you decide you needed larger injectors?

 

I took my car to the dyno, and on the high end it showed the car was running lean. 16 to be exact. so I told Jerry from Eurocharged, if I could get a retune to fix that and he said "The commanded AFR cannot be maintained due to a lack of fuel. Most customers are installing the 550cc injectors to fix this issue." so I got bigger injectors.

 

You should list your mods to your car since you're modified. That way somebody who has done the larger injectors can offer some more advice.

 

When I had the Graphite 6, with the 181 pulley it was also leaning out. The fix was to raise the fuel pressure with a larger pump, and adjustable regulator from Needswings I never needed to change injectors....... I was seeing 18-19 psi of boost.
As someone else stated, if you list your mods, it is easier for people to help.............

 

Yes, this was exactly my experience as well; except I'm running a 62mm Karmen SC pulley and N.W.'s large manifolds w/ crossovers. 60p.s.i. @ the rail. I did have my stock injectors serviced(Witchhunter). Not sure if that was needed or not; did it for peace of mind.

 

I have never heard of anyone successfully installing the larger 550cc injectors. Every report I've ever read says the car runs "pig rich" and they end up going back to the OEM SRT6 injectors. A higher volume fuel pump and an adjustable fuel pressure regulator is the answer to "leaning out" in most cases. Note also that the stock fuel filter has a built in fuel pressure regulator. You need to get rid of the stock fuel filter too! As someone else suggested, let us know what mods you have installed on your SRT6 so we can better offer suggestions for you. My first suggestion is to remove the 550cc fuel injectors and change your oil as there is likely fuel contamination in the oil now.

 

Thank you all for the replies. I have a 65mm pulley, ported manifolds with the crossover, needswings heat exchanger, NeedsWings Dual CAI, and now the injectors, and the Eurocharged tune.

 

You're not running a very large pulley or a stack combination so, to be honest, there was no need for the bigger injectors. You would have been better going with a bigger fuel pump first. How many miles on the car?

 

I have Needswings dual CAI, Needswings manifolds, Needswings Y pipe, 178 crank pulley, Needswings pulley saver kit, cleaned and serviced blue injectors, slightly ported throttle body, long tube headers, EC 96 tune, (runs fine on 93, some 96 tune...) wide band with Zietronix and Dashdaq. Other stuff in my signature. When I started to lean out my solution was a Pierburg fuel pump purchased from Needswings. I didn't change the filter or instal the fuel pressure regulator. I don't go lean.

Les

 

I have been using 550cc injectors for several years, they work great. that one change w larger fuel pump
eliminates messing with by pass setups, regulators looped rail extra parts etc.
get a larger fuel pump with the 550cc injectors easiest way and happens to be more economical in my case
now you are ready for a real dynotune instead of a canned one.
in short 550cc injectors, and a bigger pump. the end
ii am running stacked pullies 181 lower and a 65 ec upper.
no issues after tuning besides a smoother running engine.

 

Well I just wish the tuner would have said that.

 

If I could I would have gotten a custom tune, problem is here in PuertoRico, nobody has touched one, so the only choice I had was Eurocharged. But thank you for the advice. Did you change the fuel filter regulator when changing the fuel pump?

 

Ok, thank you for the advice.

 

I'll be taking the car to the dyno to see how its running. Today I drove it for a while and it feels sluggish compared to before. So hopefully after the dyno and some datalogs, maybe we can figure out whats going on.

 

For the tenth time, going lean is a function of the boost reducing the EFFECTIVE rail pressure. Raising the rail pressure solves the issue and I worked to develop a boost regulator that provides a fuel regulator pressure signal (compensation port) related to the manifold boost. As the boost goes up, the regulator signal and therefore the rail increases, but its regulated and not a one to one curve. I tied my boost to the fuel regulators boost port and when I was over 21# boost my fuel / air ratio fell to 8:1, obviously stock injectors can flood the engine if the rail pressure is adjusted.

Rob was selling the kits that resulted from this boost - regulator design and compensates for higher than stock boost. As you add air ( boost) the fuel demand increases, all the while the boost is pushing against the injector and increasingly reducing the fuel pressure DIFFERENTIAL on the injector, starving the engine.

When starting the engine with the throttle SHUT the engine will SUCK fuel out of the injector EVEN WITH THE FUEL PUMP NOT RUNNING,and keep running. WHY because the 20" (-10 PSIG) of manifold vacuum is enough to draw fuel thru the injector because of the pressure difference across the injector. Bigger injectors only reduce some of the restriction to "aid " fuel delivery. Raise your rail pressure to 60 # or so and youll see lower F/A readings.

Woody

 

I too had the adjustable regulator, with the "boost compensation" from Needswings, which also allows monitoring boost/ fuel rail pressure etc through a Zietronics box. I set the regulator at 65 psi, and without any compensation from the system, it still wouldn't lean out. I was running about 19 psi boost, and found that any compensation would make it run rich, so on this current car (with 62mm pulley), I am going to see what happens with just an adjustable regulator/filter/pump replacement from Needswings, without the boost compensation, to see what happens. this was all with stock injectors, on a dyno.

 

What if you set your base pressure at 45 psi and added boost to a 1 to 1 adjustable regulator