Hot start / warm start / restart issues again!

[Laird Scooby]

Originally Posted by Laney760

There is no way this could be linked to throttle cable is there?

Shouldn't be. I'm not all that familiar with the Prins system Ellie but do you know if there's an emergency "Start on gas" procedure?

Many systems offer this, most follow the format of switch ignition on (but don't try to start it), move the LPG changeover switch to petrol then back to gas/auto then without turning the ignition off, start the car without touching the accelerator.

If so and you could try this so it starts on gas without using petrol to start then run for the first few minutes, it would prove whether it's petrol related or more like an ignition fault. If it starts fairly easily on gas then it would be fair to say the ignition side is ok so down to the petrol side.

A quick online search suggests this idea won't be possible to try with yours unless you happen to know of a method for it.

[Laney760]

Only just really understanding what Bob wrote: ''Flooring the accelerator stops the injectors working and flooding the cylinders'' I didn't know this, my mechanical knowledge is limited.

Could I need a new ECU?

[Laird Scooby]

Originally Posted by Laney760

Only just really understanding what Bob wrote: ''Flooring the accelerator stops the injectors working and flooding the cylinders'' I didn't know this, my mechanical knowledge is limited.

Could I need a new ECU?

Bob has simplified that somewhat, flooring the throttle and holding it there before turning the key doesn't actually stop the injectors working. It fools the ECU into thinking that the throttle hasn't been touched so it only injects enough fuel for idle but with the throttle wide open, the engine can get as much air as it needs to be able to fire if the mixture is excessively rich.
It als helps the excess fuel vapour (gas or pterol) to disperse out through the air intake, reducing the excess richness.

Also the MAF is only sensing a cranking airflow, not a highrevving engine airflow so again, the ECU only injects enough for an idling engine.

Pumping the throttle doesn't have any effect on an injection engine, especially an LH2.4 as there isn't anything on the system to tell the ECU the throttle is being pumped. As far as the ECU is concerned, the throttle is either at idle position or it's not.
If it's not when the key is turned to start, it generally assumes you're proceeding as for a flooded engine so minises the injector time.

I don't think you need a new ECU but that isn't to say it should be ruled out. It does seem odd these problems started with a duff fuel pump and haven't improved much with the replacement from Sweden.

[bob12]

Thanks Dave.

Yes, these days I am rather short on words of explanation as I pass through these posts and leave the more techncal input to you!! I would add that I don't floor the pedal until the thing won't fire after a couple of seconds then it's foot to the metal without turning the key off just keep cranking. Same effect/thing as you are saying but in more tech.detail.

Different subject but, as often commented on here. Bought a couple of items today via main dealer (not stealer). One item cheapest I could find was £15 (Parts Monster, pfv in disguise) and others on eBay at up to £30+. From Volvo Classic, Sweden, via main dealer 5 mins down the road, £4.68!! I won't comment on the £6 for the other plastic item a 60th the size of the other but not available elsewhere.

Bob

[360beast]

Originally Posted by bob12

Thanks Dave.

Yes, these days I am rather short on words of explanation as I pass through these posts and leave the more techncal input to you!! I would add that I don't floor the pedal until the thing won't fire after a couple of seconds then it's foot to the metal without turning the key off just keep cranking. Same effect/thing as you are saying but in more tech.detail.

Different subject but, as often commented on here. Bought a couple of items today via main dealer (not stealer). One item cheapest I could find was £15 (Parts Monster, pfv in disguise) and others on eBay at up to £30+. From Volvo Classic, Sweden, via main dealer 5 mins down the road, £4.68!! I won't comment on the £6 for the other plastic item a 60th the size of the other but not available elsewhere.

Bob

I always phone FRF in Swansea now for a quote on parts first as more often than not the price is either cheaper or negligible compared to an aftermarket item.

[Laney760]

Originally Posted by Laird Scooby

I don't think you need a new ECU but that isn't to say it should be ruled out. It does seem odd these problems started with a duff fuel pump and haven't improved much with the replacement from Sweden.

The new pump was fitted Oct 18 and the problem started in Aug 19 so there may not be a link, I will find the Volvo receipt over the weekend

[bob12]

Originally Posted by 360beast

I always phone FRF in Swansea now for a quote on parts first as more often than not the price is either cheaper or negligible compared to an aftermarket item.

Thanks, yes, I always do. I am a big advocate of FRF but, for these two small cost items the postage brought it to about the same if not more (petrol excluded) than popping round the corner to the local main dealer. I also enjoy rolling up in their forecourt with my 31 year old 745 that came out of the same showroom (different name)! It's also easier to 'deal' with Squire Furneaux if the if there's a problem, especially as you pay on collection. I now just await a call from SF to say the parts are in from Sweden.

Bob

[Laney760]

Bob12, thanks for the heads up re full throttle

So today I tried starting with foot fully to the floor as you said (instead of a full pump of the throttle and then foot 75% down) and she started immediately so then I turned the engine off and restarted and she will start time and time again as long as the throttle is fully engaged. (I had got better at the starting these last couple of weeks after a few embarassing waits for restarts, two 5 minute ones at petrol pumps and one 10 minute panicked one causing a major hold up of traffic in Marlow one Monday morning!)

Bob12, my way of starting did not always allow for a restart, yours does, thank you!

I am going to get to the bottom of this, will keep you all updated

[bob12]

Originally Posted by Laney760

Bob12, thanks for the heads up re full throttle

So today I tried starting with foot fully to the floor as you said (instead of a full pump of the throttle and then foot 75% down) and she started immediately so then I turned the engine off and restarted and she will start time and time again as long as the throttle is fully engaged. (I had got better at the starting these last couple of weeks after a few embarassing waits for restarts, two 5 minute ones at petrol pumps and one 10 minute panicked one causing a major hold up of traffic in Marlow one Monday morning!)

Bob12, my way of starting did not always allow for a restart, yours does, thank you!

I am going to get to the bottom of this, will keep you all updated

Thanks Ellie. I look forward to your updates.

To me it's clearly a temperature thing but what/where baffles me. Cold weather is no problem. It fires up 'on the button' as long as the battery is good. Then, if I stop for about more 20 mins it won't start so it's foot to the floor and off we go. As long as you don't stop for more than 20 mins the car will start and start again.

When the weather warms up usually to start first off it's the foot to the floor procedure. It will then start and start again 'on the button' .... unless, again, I stop for more than 20 mins and then again it a foot to the floor job to start.

My starting problem has absolutely no affect on the excellent running engine performance or consumption whilst driving.

Bob

[Laird Scooby]

Originally Posted by bob12

I also enjoy rolling up in their forecourt with my 31 year old 745 that came out of the same showroom (different name)! It's also easier to 'deal' with Squire Furneaux if the if there's a problem, especially as you pay on collection. I now just await a call from SF to say the parts are in from Sweden.

Bob

My beast came from Squire Furneaux as well Bob :



You can see the dealer flash in the rear widow and if you squint, the number plate still carries their name too.

Slightly off-topic but hopefully interesting!