lxcoupe

iTrader: (8)

I have a stumble start condition that only developed recently. I have about 1000 miles on the new motor. When it was new it would always fire immediately, when hot or cold. Everything was new at the time of the motor, battery, starter, etc. When the motor is hot/ up to operating temperature, it fires very quickly, just like it did when cold when the motor was new. However if I leave it overnight, it kinda stutters/ stumbles but still starts quickly, just not cleanly. I have a fuel pressure gauge on the car, with the key-on, pressure goes to 58psi, then after a second or so it goes down to 50psi, which I think is normal. It doesn't crank forever like when you have a bad fuel pump check valve, it fires pretty much right away, but stumbles on its way to idle, if that makes sense.

I did let the battery die a few weeks back, but it doesn't make sense that it starts fast when the motor is hot. Would a loose timing chain affect start-up time? I wonder if the Bosch aftermarket starter is having trouble keeping up with the compression.

farmington

iTrader: (14)

a warm motor is harder on a starter than a cold one with high compression.

Old Geezer

iTrader: (3)

There's a forum for such problems...Called diagnostics/tuning.

lxcoupe

iTrader: (8)

I pulled the injector rail and had a helper prime the pump, I get a squirt from #8, meaning the injector is leaking. Going to have all of them flowtested again and pressure tested @ 58psi them I'll check back in with the results.

RockinWs6

Carefully check the intake bolts, what you describe is classic intake vacuum leak cold. Once the engine is warm the intake seals much better and the symptoms disappear.