Cranking Fuel Trim

[JustinC]

KPRO

2005 Honda S2000

ID1000cc Injectors

Aftermarket fuel rail with stock pulse damper

I was wondering if you could assist me with a cranking issue. With the ID1000s I have to use a cranking fuel trim of -38% in order to allow the car to start up properly. I have adjusted the voltages and dead times to match the injectors with my static fuel pressure.

I know that you state the cranking ignition values are on the low cam ignition table in columns 8,9,10 and rows 1&2. Is it also true that the fuel tables in this same table can be trimmed to allow a better startup?

[Spunkster]

It does not read the fuel tables at startup.

[The Spectacle]

Justin I posed a similar question a while back
http://www.hondata.com/forum/viewtopic. ... highlight=

Quote from Hondata

Our testing of the ID1000cc injectors in a S2000 shows that the spray pattern results in a longer cranking time than stock injectors. Datalog and calculate the time interval from the start of cranking until the engine reaches 1000 rpm - 0.5s is normal for stock injectors; the 1000cc injectors take 2-3 seconds.

For reference your initial injector pulse should be 12ms at 60F, decreasing to 6ms at 160F.

If you are getting other behaviour (engine fires, but takes a long time to reach a stable idle), then post a datalog of the problem. Otherwise, a long cranking time is a characteristic of those injectors.

I only messed with the injector pulse comp table one time and the car fired up faster than stock, don't remember what my cranking pulse is. Try throwing in the values Hondata stated.

Also while we're on the subject...if Hondata posted what should be the standard comp values for the injector pulse, then the stock S2000 kal are wrong. They're way off from that. If not, it would help to put something in the help file that lets people know that changing these values will help with aftermarket injectors, not just the cranking fuel trim.