Help please!? won't stay running after rebuild

mykhuh · Post by **mykhuh** » 25 Oct 2021, 16:27

Hello,
I've got a 2007 s40 non-turbo.
the timing belt ate a broken alternator belt and all the valves were bent.
I rebuilt the top end and got it all back together.
On cold start the engine starts up and sound normal. When the idle drops down after after about 5 seconds @ ~2k rpm it sputters and dies. It intermittently doesn't want to start at all after this happens.

Notes:
I've quadruple checked the timing and it seems to be good
I've tried multiple battery resets, grounding the disconnected positive for 15 minutes.
I tried swapping fuel relay
I can sort of keep it running with throttle application, but it doesn't sound/feel normal
The car had never done that prior to rebuild which is why I don't think its related to fuel system (unless there's some air caught in the system, or....?)
There are no codes thrown
I had previous issue with water damage to the main harness connectors below the passenger a-pillar, but never experienced this particular symptom. (I dissassembled the connectors and removed all corrosion - it was working well on test drive until belt snapped)

Where should I look next? Thank you SO much in advance!
-Micah

Post by **volvolugnut** » 25 Oct 2021, 16:53

Put a fuel pressure gauge on at the engine fuel rail and watch it as the engine dies. If pressure drops before the engine starts to die, it is a fuel problem. If fuel pressure stays strong, it is not the fuel.
volvolugnut

Post by **RickHaleParker** » 25 Oct 2021, 18:56

Sputter is Fuel/Air. Check the pressure as Lug Nut suggested then start looking for Air leaks.

SirBrickWagon · Post by **SirBrickWagon** » 26 Oct 2021, 09:24

hey, not sure if this helps but my automatic 850 would stall for a while a couple days ago. dumb question, but is your intake hose fitted and the sensor plugged in?