rough cold start

[rede30]

What are some common causes for a slow start when the engine is cold? My idle is pretty solid but when the motor is cold it takes a little long to start. My first thought was an old fuel pump not holding pressure but that is not the case. Is there anything else in the fuel system that would allow the gas to not stay near the injectors after the car is off? Other than gas, any other thoughts? Would an air leak cause a slow cold start?

this is on a m20b25.

[blocke]

Leaky FPR?

[jlevie]

The most common cause of hard cold starts is one or more intake leaks. A smoke test of the intake is the way to find them. It makes little sense to investigate the other possibilites until intake leaks an be ruled out by a smoke test.

[rede30]

smoke test tells me there are no leaks in the intake system. I think I am going to try and get to the ecu coolant temp gauge. Any other ideas?