Northern_aqs

I've installed a VEMS system on my 951 and am trying to correct a difficult to start (cold) situation.

The Auto VE analyzer works sufficiently well based upon experiences so far but something isn't correct in the initial config file for my car. Just having trouble getting basic answers. I plan a complete installation thread shortly, but I'm waiting until I get this back to OE drivability.

What should my cranking ignition advance be?
Will running 630cc Siemens injectors effect start up?

The car:

87 951 with stock 2.5 with 22k miles from new
26/8
Siemens Decca 630cc injectors
2.5 bar FPR
It still has the cycling valve and runs 10psi boost on VEMS and WG springs control. I have bought a boost solenoid for eventual VEMS managed boost control but don't have enough info to install it.
New TPS (Porsche part number).

Prior to VEMS install the car started and ran great. It was chipped to 15 pounds boost and running the stock WG.

I've linked to a YouTube video of the car starting cold yesterday.

Any help is appreciated.

Raceboy

Lawrence, I already sent you a modified config file to your email. You sent the log file to me on weekend, I was away.

odonnell

I don't have VEMS but this is generic tuning config:

I have my cranking advance set to 10* and it starts well.

For fuel, recommended practice is to start lean and work your way up. It's easier than starting rich and working down. Pick something sane like 110% and crank the car from a completely cold start. It probably won't catch quickly if at all. Just add 5% until you're happy. But be mindful that you look at the temperature of the coolant (usually X axis) as you do this procedure, the temp will increase along the way.

V2Rocket

Did you set the injector size to your new injectors?
It is likely the first file that you got was made for stock 951 injectors.
It looks/sounds like it needs more fuel. Your injectors are probably rated at 3 bar but since you are using 2.5 bar you need to adjust the injector input a little bit anyways.


But Peep will set you straight!

Northern_aqs

Thanks for all the responses. Peep has sent me a new config to try.
The injectors were set to 630cc already by Peep in the initial config.

I'll try with the new config tonight.