Warm-up peculiarity in '96 945 LPT

[AllHailKingVolvo]

Hi all,
I've noticed that my 940 has an odd quirk, which I think may either be down to an iffy CTS or Lambda Sensor...would love your thoughts.

If I start it and let it warm up for a couple of mins before driving away, it runs smoothly, pulls hard under power and generally does 940 stuff (ie being a superb motor car!). However, if I start it and drive off straight away, even if it's already warm, it never really settles into a smooth rhythm, can hesitate a little under heavy load and generally doesn't feel as "dialled in".

Any ideas as to why she likes to collect her thoughts for a min or two before setting off? It's not a problem as such, I just factor it into my departure time, but am curious.

Thanks in advance for any and all advice!
Phil

[griston64]

Originally Posted by AllHailKingVolvo

Hi all,
I've noticed that my 940 has an odd quirk, which I think may either be down to an iffy CTS or Lambda Sensor...would love your thoughts.

If I start it and let it warm up for a couple of mins before driving away, it runs smoothly, pulls hard under power and generally does 940 stuff (ie being a superb motor car!). However, if I start it and drive off straight away, even if it's already warm, it never really settles into a smooth rhythm, can hesitate a little under heavy load and generally doesn't feel as "dialled in".

Any ideas as to why she likes to collect her thoughts for a min or two before setting off? It's not a problem as such, I just factor it into my departure time, but am curious.

Thanks in advance for any and all advice!
Phil

ECU is getting old and forgetful.............like the rest of us

In all seriousness I have heard of this before and my 940lpt which is also a 96 likes a minute or two of warming up / getting ready before I take off.

Not sure exactly what it is but it's like the ECU is getting everything sorted fueling wise etc before driving off. A bit like us getting up having a stretch and a cup of tea before we leave the house

[Laird Scooby]

Originally Posted by AllHailKingVolvo

Hi all,
I've noticed that my 940 has an odd quirk, which I think may either be down to an iffy CTS or Lambda Sensor...would love your thoughts.

If I start it and let it warm up for a couple of mins before driving away, it runs smoothly, pulls hard under power and generally does 940 stuff (ie being a superb motor car!). However, if I start it and drive off straight away, even if it's already warm, it never really settles into a smooth rhythm, can hesitate a little under heavy load and generally doesn't feel as "dialled in".

Any ideas as to why she likes to collect her thoughts for a min or two before setting off? It's not a problem as such, I just factor it into my departure time, but am curious.

Thanks in advance for any and all advice!
Phil

Could be down to one of a number of things Phil or possibly a combination of two or more things. Aside from the obvious first thoughts (plugs, air filter, rotor/cap, air leak between MAF and throttle body, dirty throttle body, dirty MAF) the thing that comes to mind is condensation in the tank. Simple reason being, it happens after the car has been sat and the condensation has time to gather in the bottom of the tank. Letting it tickover for a couple of minutes disperses the condensation so normal running is resumed.

Could also be worth simply pulling fuse #1 for 30 seconds in case it's picked up a spurious fault. That's what i'd try first, run it a day or two and if it returns, try the meths treatment for the condensation, pulling fuse #1 a couple of days after adding the meths (2L of meths to ~1/4 tank of fuel) and see what it's doing then.

[TonyS9]

I think I have noticed something similar on occassion. It just seems to run slightly badly, but stopping and starting cures it.

There is a weird software feature that keeps the idle high until you stop after it has warmed up a bit. Is your speed sensor working?

Could be something 'old' like injectors, O2 sensor or something but I'm just guessing. Hasn't really been worth my while investigating, runs fine most of the time.