Sorry the only reason I asked if it was having issues only when cold is I was thrown off with the misfire. I wasn't sure if the misfire was now even when warm even when he stated in his first post it was a cold start issue.

When my Talon had cold start issues is was the coolant temp circuit and oxygen sensor. It was not enriching enough since fuel does not atomize that well when its cold. Since you have a fairly new car I doubt an oxygen sensor would help. The coolant sensor code took a while to throw and it was intermittent lighting anyhow.

I agree some pictures of your setup would be pretty sweet!!

 

I will send pictures of the LPG setup later - they are digitally controlled injectors with its own ECU.

Here you can find todays starting log - the first minute after cranking. You can seee the hesitation in RPM, but other parameters seem fine to me - or can you see anything wrong there???

 

What should be the air preassure in manifold during idle with all components (A/C, defroster etc.) off?

 

Not sure why you edited your last post... -16 to -20 in/Hg is pretty normal, usually toward the higher side of that.

It depends alot on your MIVEC settings, cams, load on the engine from accessories, and a few other things.

 

I have changed the login my previous post for a better one from last morning.

MIVEC and cams stock. I do not think people change Mivec at idle.
I can see about -35 kPa, which is -10 in/Hg, could it show vacuum leak?

 

My MIVEC is changed slightly at idle / startup, but it may only be in the warm map.

-10in/Hg seems pretty low. That could definitely indicate a leak, but it could also mean that the car isn't pulling enough vacuum against the butterfly because of low idle (not the case here) or some other reason.

I'm still not clear if you did a post throttle body leak test. I'm not sure of the actual procedure, but I believe it involves putting the engine at TDC so all intake valves are closed, then pressurizing the IM with the butterfly valve open (not sure how we can do that either since we're electronic throttle now. Might be able to with a friend in the car, the key in the "on" position, and pushing on the pedal). This would show if you had any leaks. Otherwise you can just look for disconnected hoses / etc.

 

Well, I will check for the leak mor precisely.

Hereby I post some pictures of the LPG injection system and the fuel tank in trunk.

 

Not sure if it is possible w/ your mods, but can you flash your ECU back to factory settings and see if the problem persists? If it does, you know you have a hardware problem. If not, you know it's your map.

 

I know it is a HW problem - all maps including stock behave the same :-(

 

I have exactly the same problem with my GSR. My setup is

HKS GT3240 turbo kit
HKS race intake
HKS UICP, LICP, FMIC
75mm test pipe
HKS HI-Power exhaust with Apexi ATS
HKS forged pistons
HKS forged steel piston rods
HKS camshafts
HKS head gasket
HKS MX45 spark plugs
HKS 1000cc injectors, HKS fuel rail, HKS pressure regulator
upgraded fuel pump
Perrin 3 port boost solenoid
Boomba oil catch can
HKS SSQ VTA BOV
Stewart Warner shiftlight (connected on ecu pin 4 - the no1 cylinder coil driver)

I wonder what we have in common besides european gas. I have this problem since outside temperatures dropped and only when the engine is cold. Otherwise I get a happy 820 RPM idle.

Ninja edit: my *-vs-coolant-temp tables are not modified

 

I have the same - the car has to be stopped for more than 5 hours and then I have this problem.

How about driving after start? My car moves but is terribly lazy for first 1-2 minutes and does not want to rev.

 

Driving right after cold start is difficult. The power drops randomly so bad that i have to engage the clutch to keep engine from stalling.

I did an extensive search on google and it seems that the problem is related to dirt deposits built in the intake elements: IACV (subaru and mitsu), VANOS (BMW), BOV, throttle. I'll go for a thorough cleaning as soon as the rain stops tomorrow.

 

For the crappy running while cold, try zeroing out the cold running ignition retard map.

- Bryan

 

Thanks.
Could it be the "Ignition warm up" map in ATR? It has values 3-5 in all cells.
Or "Ignition Reduction" with values 2 (higher load) - 14 (lower load)?

 

Exactly the same problem.

I have had the throttle body disassembled and cleaned completly as well as the MAF sensor. The manifold has been cleaned with a cleaning spray, but problems survive...