Strange starting issue

[Tunnelmotor99]

2001 Lesabre with ~136k miles. In the past 2 years it has developed a problem where after sitting overnight or for several hours, when you turn the key to start it will turn over for a second or 2 then it’s like the starter cuts out. You can turn the key off and start it again and it starts fine every time. Occasionally once it starts after the second try the engine runs rough until you give it some gas and then it smooths out. I’ve changed the crank sensor to no avail and there are no codes. I haven’t done the fuel pressure regulator but I did check the fuel pressure and it was within specs. I recently replaced the intake manifold and did new plugs & wires. It runs great otherwise, it’s just annoying to have to start it twice. Ideas???

 

[RD_Atlanta]

Could you please be more specific regarding "then it’s like the starter cuts out" on the first start attempt?

 

[MelsRegal]

You stated you tested the fuel pressure but made no mention how long the pressure remained after turning off the engine?

 

[DrivenDaily]

Scan it for codes.

How old and/or what state of health is the battery in?

 

[02LTD2.0]

Start with changing your fuel pressure regulator..,... it's cheap and quick to do. If it continues to run rough after that then try disconnecting your MAF sensor.

 

[HotZ28]

Good suggestions above, but I am confused about what the OP said "replaced manifold"? Was that just the the UIM, but not the LIM gaskets? Both can leak coolant as well as the fuel pressure regulator, or leaking injectors into the cylinders and cause a hydro-lock symptom after the engine sits overnight or for a few hours. I would start by pulling the vacuum line to the FPR to see if there is any fresh gas there & pull the dipstick and see if there is any smell of gas in the oil & then look @ the plugs for any signs of coolant in the cylinders. Maybe the OP can help clarify my concerns & questions?