Signs of Life - Injector Question

[twacker]

1995 Rebuilt engine, cams, 11.5 compressio. I was planning on runnning stock DME, euro air flow meter, stock 17 injectors for the break-in periiod before I go to a TMS chip and 24 injectors. This was my original plan. She started but only on 2 cylinders, if you want to call that starting. Did some dianostic work and found that only 2 of the injectors are firing. These injectors were old and abused.

Now the question: I already have the new 24 injectors but not the TMS chip for this application. Will it hurt to install the 24 injectors without making the TMS chip change for the time being. i.e. until I get one ordered Monday.

[shim]

i think you will run a little rich

[twacker]

I figured but was hoping the DME could compensate the pulse length time. I'll just have to grin and bear it until Tuesday night. Gotta love next day air.

[shim]

actually, someone posted something similar to this on M3forum & Serious mentioned a good point:

from Serious "fuel economy is the same. and the car wont run rich. the computer still controls how much fuel enters the engine but you just opening up the maximum amount of fuel that flow through the injectors. ONly drawback is the price for new injectors and software."

[///MacDaddy]

I definately wouldn't run it without the correct software.

[twacker]

I resolved myself to change the injectors out and just do idle diagnostics for the weekend. Road test when the chipe gets here. There's still plenty of loose ends to tie up and this is the perfect excuse not to drive the car for now. Thanks for the input. I'll give an update once she's on the road.

[BMW///M3sdn]

I don't know that much about the injectors, but i thought that the DME controlled the length of time it was open, if it's a larger injector that can put out more fuel wouldn't it put more out in the same amount of time than the stock 17# injectors?

[Erik@EDGE]

Serious was wrong. the last poster is correct. The DME thinks it has 17lb units so it pulses them accordingly, they will run mega rich, and with your fresh rebuild, I would be concerned about washing the cylinders with fuel. Best bet, wait till you get the chip to start her up.

[twacker]

Painful, but that's what I am going to do. Thanks.

[Erik@EDGE]

NP, nothing worse than being SOOO close you can almost smell the rubber burning. Patience daniel-san..