MicroSquirt.com read only forum (Jan.15,2018)

Running port fuel injection on a olds 455. Car starts and drives very well at all times, with only one exception. When the car sits for 2 days or more it will crank and crank without starting.

I am running a return fuel system with a MSD pump, all-6 lines, and an aeromotive reg. Fuel pressure is 40psi and it comes up very quickly once the pump is turned on.

It is currently summer here, and the engine temp never goes below 80F, so I don't think it is temperature related.

If the car sits for 1 day, it will start almost instantly.

If the car sits for 2 days, it will be very very hard to start.

Ideas? I first thought it was fuel draining back, but that doesnt seem to be the case. MS is not resetting during cranking either.

what ms are you running ?

i get exacly the same problem.

it almost feels like there's no spark durnign first cranking attempt, the second time spark comes on two seconds into cranking and then engine starts. it might not be the spark, but i definitely do hear injectors ticking.

this is so wierd... i'm tearing my har out over this one... and i thought it was only me, probably doing something wrong, but you have the same issue i see...

Try richening up the warm end of the Cranking PW`s?

i dont think it's related to cranking pw at all.

it's the first start that doesnt happen. then you stop cranking. restart igniton and then it starts ok (takes a bit of cranking). once it started and run for 2 seconds you can shut down the engine and restart it and it will start 1st click.

ws6,

To me that sounds like a leaking injector flooding the intake manuifold, which then has to be cleared with lots of cranking. After the first start you are okay again, unless enough time passes for a significant amount of fuel to leak and flood the engine.

Lance.

Lance, thanks for input, i'll check it out. warm starts are ok, but you are right it might be leaking injector. Wierd it all happened as i upgraded firmware to 2.684...