running lean
 

Went for power run on the dyno today had to pull off cause was 14.1afr at 6000rpm, is exended port single turbo fd running 12psi with walbro fuel pump, last run was 272rwkw @12psi. would this be the fuel pump droping, or the fuel press regulator?

fuel pump wiring?

What size injectors?

Not sure of fuel pump wiring? No good with wires. Still 550s an 850s do think should get bigger secondarys and use stock secondarys for primary?

Are you logging fuel pressure?
Do you have a gauge on the FPR you could watch?
What was your injector duty cycle?

First, replace that Walbro with an Aeromotive Stealth 340lph, or a Supra pump. And of course, rewire it. Leave no question that you have enough pump.

For injectors, yes, I would upgrade. Do not put the 850's in primary, you will have low driveability and idle issues. No reason to go any other route then Bosch EV14's. No resistors or driver needed.

www.fuelinjectorconnection.com
Ask for John, he will hook you up. I would go with 720/2000 for future expansion. Yes, these injectors are half as much as Injector Dynamics. Yes, they are the same injectors. Yes, John pulse width matches them just as ID does. I would upgrade the rails and a proper FPR at the same time.

With the Bosch EV14's, you can get 4x1000's. These are MUCH easier to control while tuning. 1000s in the primary are not as big an issue. A little lag is required, but they are work well.

Stock injectors are 100% DC at around 250kw.

Fuel pump is probably the cause. Same thing happened to me when dyno'ing earlier this year. Replaced the Walbro pump that had been in there for years and fuel deliver was able to keep up with the ole air pumping through the motor. :)

Stock secondary injectors don't support much power either. 100% duty cycle and AFRs in the 14 range means you are ready to blow the motor.

Check the FAQ thread for some good threads on the topic of fuel pumps and injector sizes. One by GoodfellaFD3s

Will get new pump an injectors an see how she goes, thinking going for bosch 044, and 720s 2000s. motor only done 10000km on full new block and streeter so hope motor not toost