I believe the act of cranking is relatively benign compared to running with cold oil.

 

Mine is the same way - I can sometime get it to start a little faster if I work the throttle. In my case I have tuned the car to no end with the starting tables to the point that the next step down the car will not fire because its at 0....I haven't even had a change that i thought hmm I am onto something here.

I do not believe its starting rich or tuning - from the trend I am noticing the car is not even getting fuel on my first set of cranks, because when i stop and the crank again the car will fire up no problem and the pulsewidth matches that of the first set - now why wouldn't it fire? I have my wideband setup that it doesn't lose power under cranking and I can watch my wideband gauge and the first set of cranks it doesn't show a rich condition that its over fueling..

It seems something is locking the injector to not open properly or function properly on that first set of cranks and the car just isn't getting proper fuel....because once i stop cranking then start again it fires like it should.

 

The temp data that you took was this with the magnus manifold, etc already on the car?

 

mine as well........

the only thing i have disabled on my car is the egr - same as dan, so I know nothing in that realm is interfering.

 

yes that was with the magnus.



just an FYI... the car didn't seem to start ANY better with the magnus than without it.

Also,
this week in particular my car is starting like ***. NOTE: VERY cold.

 

Well I got the new o rings from tony today, installed them and no change...

 

That's what I expected, but figured it was worth a shot.

 

Thanks again Tony... for everything so far

 

Two things:

1) For everyone: I haven't had time to do a thorough followup test, buy my initial test of relieving the fuel pressure in the rail until just before starting seems to stop the issue. Can a few other people try disconnecting the FPR from the rail and leaving it disconnected until just before trying a warm start?

2) Can someone build and send me a voltage divider that converts 16 V to 5 V so I can log voltage at the injector?

 

It would probably be cheaper to just go grab two resistors from radio shack then to have somebody send you them.

Any idea what kind of electrical impedance is on the input?

A 10k Ohm and a 22k Ohm resistor in series should do it and should be standard values.

If that doesn't work, I could probably build something up real quick at work on Monday.

 

You will need high precision resistors for best results. If you do a 330 ohm in series with a 100 ohm and tap in the middle with the 100 ohm connected to ground and the 330 ohm connected to VCC, that knocks down the voltage by 0.3125 or 14 volts will look like (14*0.3125) = 4.375,

 

I will relieve the fuel pressure after start up and see if it starts better.

 

Some interesting information I ran across reading up on injectors today... http://www.stealth316.com/2-injectortypes.htm

Upon reading this I am going back to Dan's original assumption as this being the driver circuit issue... when converting to high impedance injectors...

With peak hold injectors/resistor pack, the circiut allows higher current flow through the injectors solenoid which open the injector faster.

When you put in the high impedance injectors this drops the initial current flow through the injectors down, thus taking longer for the soleniod in the injector to "charge" and to open the injector.

The only way I can see combating this is to change the cranking primer initial pulse ( to crack the injector open faster)... I will try this later today...

 

Wow, thanks guys for working so hard on this. Do the ID2000 units do the same thing?

 

The ID2000s do not have this problem that I have encountered.