Cold Start Problem

ImAuthenticFTW · Post by **ImAuthenticFTW** » Wed Jul 15, 2009 9:01 am

Ever since flashing my car with the MAP based K&N race header map my car takes a few seconds to start where as before it would start instantly. Also now when i cold start i get a very loud clunk as the engine turns over. Ive been trying to include a datalog but it wont load so ill try tonight on another computer, i did notice that i am gettin knock retard of 4 upon start

edit: ive added a new datalog from just now when i went to start the car, the knock % reaches 100% and in my other datalog (which for some reason wont open now) it pulled 4 degrees of timing at start up...

Post by **Hondata** » Wed Jul 15, 2009 9:50 am

You need to change the cranking fuel compensation. Try decreasing the fuel in 10% intervals until the engine becomes more difficult to start, then increasing the fuel until it has too much, then set the cranking fuel in the middle.

eg. Decreasing the trim the car becomes hard to start with the cranking trim at -50%. Increasing it it takes longer to start at +30%. Set the trim to -10% (median of -50% and +30%).

ImAuthenticFTW · Post by **ImAuthenticFTW** » Wed Jul 15, 2009 1:34 pm

would that also take care of the knock that is happeneing furing start up as well?

Post by **Hondata** » Thu Jul 16, 2009 12:01 pm

Can you hear knock when the engine starts? It most likely is mechanical noise from the engine starting.

ImAuthenticFTW · Post by **ImAuthenticFTW** » Thu Jul 16, 2009 12:40 pm

what I hear is a very loud clunk that sounds like metal on metal. and as they clunk happens my knock % gets to 100. it also seems like the engine wants to shut off when the clunks occur......

ImAuthenticFTW · Post by **ImAuthenticFTW** » Sun Jul 19, 2009 8:28 pm

So just curious, i know the knock sensor is pretty much a mic for the motor. But how sensitive is it? i have a feeling my header is rattling (putting it on a lift tomorrow to verify) but would the knock sensor pick up that noise?

Post by **Hondata** » Mon Jul 20, 2009 8:55 am

Yes. The knock sensor will pick up any mechanical noise.

Dawid S · Post by **Dawid S** » Mon Oct 12, 2009 1:08 am

The same problem here, but with European Type R FN2 on MAP CAL.
RC440cc, Greddy spark plugs may cause the problem ?
When car is cold and try start I have loud clunk ! Than car start up, but it looks seriously.