hiroichi1515

iTrader: (17)

Is there anyway I can tell if my car is getting too much fuel or not enough during cold starts?

The engine is an s4 n/a with the stock turbo on it managed by rtek 2.1 with about 6000 or 7000 miles on the rebuild. Once the car cranks up its fine and idles at 1100 (set by me due to no bac to control idle when e-fan kicks in), and pulls near 16 inches of vacuum. My injectors are 550cc pri and 720cc sec with an fd fuel pump. Every morning it takes like 4 minutes of cranking to get my car started. I use the deflooding process built into the rtek for about 30 - 45 secs, then i keep tapping the throttle while cranking. It makes a very loud back fire, then fires up. Now today I did the same procedure and it did not start but backfired like 7 or 8 times but they were not as intense as it usually is. I was forced to roll down the hill and pop the clutch in 2nd then the car started running perfect after about 4 seconds of sputtering.

Does anyone have any idea of what could be going on here. I don't have a single, vacuum leak, or boost leak. Also I don't an exhaust leak either, but im not sure if that could cause any issues. Please let me know what you think.

Thanks for the help in advance!!

1SWEET7

iTrader: (1)

You can change how much fuel is injected based on the temperature outside. It is called the cranking map on the Rtek. Sounds like it is just injecting too much fuel.

hiroichi1515

iTrader: (17)

I know I can change it, but I don't know whether to add or remove lol.

SirCygnus

iTrader: (1)

i usually add in a bunch of fuel.

hiroichi1515

iTrader: (17)

what injectors do you have an what is the xxms at 60 degrees or so?

SirCygnus

iTrader: (1)

about 3.5 to 4.0 ms at 60 air temp and 80 degree coolant temp on my 550's. i keep going up so that it injects a bit more. if you want, i can get a pretty good figure, but then again, its based on both air intake temps, and coolant temps, so it most likely is a correction %. but, durring the really cold days, it idles at 11.0 on a cold engine and 13.0 on a warmed up engine on a cold day.

hiroichi1515

iTrader: (17)

^^^ Are we both talking about the cranking table or are you talking about the fuel correction table and idling?

SirCygnus

iTrader: (1)

i have no idea what we are talking about.

hiroichi1515

iTrader: (17)

lol, seriously I wasn't being funny. In the starting map section of the rtek. This morning it was 37 degrees according to the rtek so I jacked up the points covering that range to 70ish. It was still hard to crank but idt fired up after two backfires back to back. I guess I will try removing fuel tomorrow morning.

blah,

sharingan 19

iTrader: (16)

I was making changes to my start up map just the other day, although it was more to fix flooding on hot starts. I cut the fuel by a good 30% everywhere above 60°, about 20% above 40°, and 10% below that.

I wast working perfectly before this recent cold snap, now it takes about 8 sec of cranking to start in the morning (ambient around 37-40°). Looks like I'll need to add back that 10% below 40 and I should be good. If you have never messed w/your starting map I would think u should be fine but u then again you are running a turbo ecu on an n/a... I'm going to guess that it needs even lees fuel than the low comp turbo motor and the map is rich even for that application. Remove fuel and report back.

lastphaseofthis

iTrader: (8)

You'll want to remove fuel on the starting "map". Altough i call it a Graph as it's 2 dementinal. the factory uses too much to start with, plus hes running 550's instead of 460's. i put mine at the lowest it would actually start, and it takes about 1 full turn of the motor to fire off. quicker then most factory new cars i drive.

hiroichi1515

iTrader: (17)

ok, im gonna drop the fuel a lot on my lunch break and give it a try. Thanks for the tip you guys.

hiroichi1515

iTrader: (17)

well i tried to drop it at lunch and the ecu decided to crash and reset itself....

Skip ahead, this morning I turned it down to 43ms and 36ms spanning 5 degrees to 40 something i believe. Anyway, there was improvement. I still had to tap the pedal, but it only took me about 30 - 40 secs as compared to the 3+ mins before. I will take out more fuel tomorrow and see what happens.

sharingan 19

iTrader: (16)

Headed in the right direction... But still too rich.
I just went and checked my map and I was@ 42 ms - 30ms going from 5° - 40° and it still took 5-8 sec to start. I've dropped it to 33ms-24ms and it tapers to 10ms after that.

I'll see how that works in the morning.

hiroichi1515

iTrader: (17)

^^ Thanks, I will definitely try that out in the morning. Let you know what happens.