Fuel Tank Pressure? Gas Fill up and then trouble starting

0piston · Post by **0piston** » Mon Oct 26, 2009 11:28 pm

I've been having trouble with this ever since I had the KPro unit installed.
But never really thought about it till today because I am worried the gas is washing my walls at startup.

Problem: Whenever I fillup at the gas station, I have to crank the engine ~15-20 times before it finally starts and gurgles to the proper idle rpm. My wideband A/F shows really rich 9.9:1 after this happens. Other than this, I have zero startup issues! I couldn't be happier starts just like a stock car at any outside temperature, except when I finally have to get gas :(

I've tried searching but I am not sure if this is a common issue, if not I can try datalogging my next fuel fill up. I have a walbro pump setup instead of stock--I wonder if this may cause this? Is there anything I can modify for a fuel tank pressure startup calibration?

Post by **Hondata** » Tue Oct 27, 2009 6:47 am

Please follow the posting guidelines here: http://www.hondata.com/forum/viewtopic.php?t=3629

0piston · Post by **0piston** » Tue Oct 27, 2009 1:24 pm

When posting a KPro problem with your vehicle, please include:
- serial number of your K-Pro
I'll edit this in later when I check it

- KManager version (not 'the latest')
1.3.9 but has also happened with previous versions

- the calibration (as an attachment)
- a datalog of a problem (as an attachment)
will attach both

- what sort of vehicle you have
2000 s2000

- what sort of ECU you are using
KPRO

- anything about the car which has been modified from stock which may affect the ECU (don't include what sort of rims you have nor stereo etc).
750 injectors, walbro fuel pump, turbo etc

- a specific description of the problem
from above, in this datalog the car started within 10 seconds a bit beter, but was still "gurgling" to get up to idle. the fuel tank was 3/4 full I don't know if this attributed to a somewhat better startup.

Post by **Spunkster** » Tue Oct 27, 2009 3:03 pm

In Misc, try enabling emisions error checking and see if the problem is resolved. You will see that an update was made in version 1.3.6.0

http://www.hondata.com/help/kmanager/whatsnewtopic.htm

0piston · Post by **0piston** » Tue Dec 01, 2009 10:47 pm

I enabled error checking, but I get a code of high voltage from my eld input. But regardless that is a separate matter, I've gone through 2 fillups with your recomendation and the same problem.

looking at my wideband, the intial start up is flooding my car. after 10-15 cranks it finally "catches" but my wideband reads max rich 9.9:1..

Unforutnately I only get startup problems when I open that damn gas cap!!!

thanks for any help

Post by **Hondata** » Wed Dec 02, 2009 8:01 am

With the calibration, OBDII emission checking must be enabled for the S2000 otherwise you will get pruge related problems. Your o2 sensor is disabled, and the o2 voltages should be adjusted too.

There is something odd with the wideband reading, because it does not alter as you start to crank the engine - it takes almost 30 seconds to show the rich condition. The cranking injector duration looks low for 750 cc injectors - 5 ms would be normal when the engine is hot, so I suspect that either the wideband is not reading correctly or there is a problem with fuel pressure / injectors at start.

0piston · Post by **0piston** » Tue Dec 29, 2009 5:41 pm

Hondata wrote:With the calibration, OBDII emission checking must be enabled for the S2000 otherwise you will get pruge related problems. Your o2 sensor is disabled, and the o2 voltages should be adjusted too.

There is something odd with the wideband reading, because it does not alter as you start to crank the engine - it takes almost 30 seconds to show the rich condition. The cranking injector duration looks low for 750 cc injectors - 5 ms would be normal when the engine is hot, so I suspect that either the wideband is not reading correctly or there is a problem with fuel pressure / injectors at start.

With the 30 second PLX wideband reading startup that is just the sensor heating up, its been like that ever since I purchased it--unfortunately it just takes that long to read A/F :( Works good though, I've had it in 2 previous cars.

I've purchased a Fuel pressure gauge that I am going to tap into my fuel rail to see if there is a drop in pressure causing the problem. As I said this problem only happens after I open the fuel cap, otherwise I couldn't be happier with cold starts, warm starts etc--much better than my old AEM.

thanks

0piston · Post by **0piston** » Thu Mar 25, 2010 1:06 pm

My friend who is a mechanic, said it is because my EVAP system is not functioning properly, Does the K-PRO ecu disable this? or is the EVAP independant of the main ECU--because I noticed under kmanager>error codes>readiness codes> EVAP says not supported when connected

The other day I tried filling up my car when it was on, and surprisingly my car's wideband was reading richer and richer until it was bogging... then after a 3 minute drive everything stabalized again.

Post by **Spunkster** » Thu Mar 25, 2010 1:38 pm

Post your current calibration

0piston · Post by **0piston** » Fri Mar 26, 2010 3:44 pm

hasn't changed much from the last, except that I am running the latest version.