Poor warm starting.

[GingerMagic]

I have an issue with the Volvo, where it starts on the button when the engine is cold regardless of the climate outside, however once the engine is warm then it's a pain to start up.

It will spin over fine, and fire up no problem, but it won't tick over unless I increase the revs for around 20 seconds, then it's good to go.

Has anyone had an issue like this before? If so, what was your problem and how did you fix it

Many thanks,
Kelv

[Clan]

Originally Posted by GingerMagic

I have an issue with the Volvo, where it starts on the button when the engine is cold regardless of the climate outside, however once the engine is warm then it's a pain to start up.

It will spin over fine, and fire up no problem, but it won't tick over unless I increase the revs for around 20 seconds, then it's good to go.

Has anyone had an issue like this before? If so, what was your problem and how did you fix it

Many thanks,
Kelv

I would guess its not holding fuel pressure when you turn it off... Thats the first check anyway...

[Laird Scooby]

I would guess you're not using the correct hot start procedure. Press your foot halfway down on the accelerator and then turn to start position from zero, hold it there and gradually press the accelerator to the floor, releasing when it fires.

The problem will be worse in warm/hot weather and almost non-existent in cold weather.

[360beast]

Originally Posted by Laird Scooby

I would guess you're not using the correct hot start procedure. Press your foot halfway down on the accelerator and then turn to start position from zero, hold it there and gradually press the accelerator to the floor, releasing when it fires.

The problem will be worse in warm/hot weather and almost non-existent in cold weather.

That would be the case for a carb car or k jet maybe but not on a 940 turbo, they should start without any assistance no matter what the temperature so there is something amiss.

I would do as clan said and check the fuel pressure.

Dave's guide could be a useful work around until the issue is found.

[Laird Scooby]

Originally Posted by 360beast

That would be the case for a carb car or k jet maybe but not on a 940 turbo, they should start without any assistance no matter what the temperature so there is something amiss.

I would do as clan said and check the fuel pressure.

Dave's guide could be a useful work around until the issue is found.

It's SOP for ANY petrol engine, particularly EFi where the mixture is usually arbitrarily enriched with the turn of the key to overcome either cold conditions (obviously cold engine) or to overcome fuel vapourisation (hot engine).
Very little wrong with the fuel pressure i would think, chances are the warm air intake valve has failed and is overheating the inlet manifold causing fuel vapourissation while stopped.

Note that fuel vapourisation will give a percieved reduced fuel pressure and many will accredit the fault to low fuel pressure, usually changing the FPR to no avail. The fact is the simple, obvious stuff is being overlooked and incorrect starting procedure being used.
To overcome this, many EFi systems have a bypass system fitted to increase fuel pressure when hot until the engine is started to overcome vapourisation.

[GingerMagic]

Thanks chaps.

To be honest I've not needed to use the warm start technique since I owned a Triumph Acclaim back in 1994...

Since then I've had mainly diesel cars, with the exception of a 1.8 Mondeo and a V6 406 Coupe, neither of which needed help on a warm start, so I'm a bit out of practice with the workings of a petrol car.

I'll use the warm start technique fo a while and see what happens, however if this doesn't seem to have any affect then I'll start looking at fuel pressure/vapourisation issues.

Dave, could you kindly help in locating the warm air intake valve and I'll cast my novice eye over it.

Cheers,
Kelv

[Laird Scooby]

Originally Posted by GingerMagic

Thanks chaps.

To be honest I've not needed to use the warm start technique since I owned a Triumph Acclaim back in 1994...

Since then I've had mainly diesel cars, with the exception of a 1.8 Mondeo and a V6 406 Coupe, neither of which needed help on a warm start, so I'm a bit out of practice with the workings of a petrol car.

I'll use the warm start technique fo a while and see what happens, however if this doesn't seem to have any affect then I'll start looking at fuel pressure/vapourisation issues.

Dave, could you kindly help in locating the warm air intake valve and I'll cast my novice eye over it.

Cheers,
Kelv

It will be in the intake of the air filter box, however not all turbos had it so you may not have one.

[360beast]

Originally Posted by Laird Scooby

It's SOP for ANY petrol engine, particularly EFi where the mixture is usually arbitrarily enriched with the turn of the key to overcome either cold conditions (obviously cold engine) or to overcome fuel vapourisation (hot engine).
Very little wrong with the fuel pressure i would think, chances are the warm air intake valve has failed and is overheating the inlet manifold causing fuel vapourissation while stopped.

Note that fuel vapourisation will give a percieved reduced fuel pressure and many will accredit the fault to low fuel pressure, usually changing the FPR to no avail. The fact is the simple, obvious stuff is being overlooked and incorrect starting procedure being used.
To overcome this, many EFi systems have a bypass system fitted to increase fuel pressure when hot until the engine is started to overcome vapourisation.

I very rarely disagree with you Dave but I can honestly say the last car I had to use throttle to start when hot was my 1984 carb 360, since then I've driven plenty of 7/900s and not one has needed anything to start when hot other than turning the key.

I think we may have overlooked something here... What fuel is it running? If it is E10 then you could very well have vapour issues thanks to the E10 boiling over at a much lower temperature than petrol. 7/900s have very hot engine bays when they're up to temperature.

The old Bentley's I worked on would have an overflow pipe for the carbs, if you had to road test them for a service and then drain the oil while hot you would often get ethanol dripping on you and that was on E5!

[griston64]

Originally Posted by 360beast

I very rarely disagree with you Dave but I can honestly say the last car I had to use throttle to start when hot was my 1984 carb 360, since then I've driven plenty of 7/900s and not one has needed anything to start when hot other than turning the key.

I think we may have overlooked something here... What fuel is it running? If it is E10 then you could very well have vapour issues thanks to the E10 boiling over at a much lower temperature than petrol. 7/900s have very hot engine bays when they're up to temperature.

The old Bentley's I worked on would have an overflow pipe for the carbs, if you had to road test them for a service and then drain the oil while hot you would often get ethanol dripping on you and that was on E5!

I'm the same when hot. Just turn key and thats it ( 900 turbo and 700 N/A )

[griston64]

In fact I've never done anything other than turn the key on a hot car.