Dreaded Flooding!

[spb2002]

So, car wouldn’t start today! I’ve not driven it all weekend as I’ve been away, and over the course of 3 days it seems to have flooded. Luckily I had a father-in-law to hand, as I’d run down the battery trying to start it and then went on to jump-start from his motor. Eventually got it started, largely due to the information on this site, so thank you!

What do you think would cause the engine to flood in such a short time? I turned the car off normally, when it was hot on Friday morning?

[warpc0il]

That doesn't sound like a flooding scenario.

Flooding should only occur if:
- the engine is started and then switched off while still cold/cool, such that the PCM is still in "cold running" mode
or
- the battery is really tired, or poorly connected, or the starter is dying, such that the engine turns over but not fast enough to fire-up.

What leads you to believe it was "flooded"?

Have you checked your ignition system?
https://www.rx8ownersclub.co.uk/forum/v ... 25&t=36282

[spb2002]

I tried starting in the usual way, no throttle... just wouldn't start, wouldn't bite. I then tried a couple of starts at full throttle, thinking that it might have flooded somehow after being stood for the weekend.. on the second go I got a backfire, but that was it. Then several cycles of 3-4 goes at full throttle (no signs of ignition) then tried to start normally... it would hunt a little, but no start. did this routine about 9-10 times, and on the last go it actually fired up like normal..... large plumes of white smoke out of the exhausts for about 30 seconds, and then that died down too. I let the car idle for about 5 mins before driving off... no coughs or splutters or anything.

[spb2002]

Have you checked your ignition system?
https://www.rx8ownersclub.co.uk/forum/v ... 25&t=36282

Not yet, I've only had the car for under a week. I know it has low compression, but so far hadn't had a reason to suspect ignition parts. Will try and check these at the weekend, cheers

[Lemon]

what did the white smoke smell like?

[spb2002]

what did the white smoke smell like?

I'm not entirely sure, tbh, Lemon. I THINK it was petrol, but I was busy at the front end putting jumpleads away, etc. that I wasn't really paying attention to the smell. I know just before it finally started I could smell petrol, if that helps?

[bigpete8]

Don't ignore what Dave said above as possible flooding cause "the battery is really tired, or poorly connected, or the starter is dying, such that the engine turns over but not fast enough to fire-up."

Also similarly applies if the car hasn't been driven much and the battery hasn't had chance to charge (20 minute drive only just about recovers what is used from a cold start)

In any event clean/check the battery terminals and charge battery!
PS The terminal design is a bit rubbish and is easy to tighten fully without it clamping correctly / can stretch over time. packing it with something suitably conductive can work short term if it has stretched. (search is your friend on this)

[spb2002]

Don't ignore what Dave said above as possible flooding cause "the battery is really tired, or poorly connected, or the starter is dying, such that the engine turns over but not fast enough to fire-up."

Also similarly applies if the car hasn't been driven much and the battery hasn't had chance to charge (20 minute drive only just about recovers what is used from a cold start)

In any event clean/check the battery terminals and charge battery!
PS The terminal design is a bit rubbish and is easy to tighten fully without it clamping correctly / can stretch over time. packing it with something suitably conductive can work short term if it has stretched. (search is your friend on this)

Cheers Pete, i'm hoping to god that the car starts again for me to drive home! when I get back i'll put it on charge overnight... I'll check the terminals whilst i'm at it. Previously the car was someone's weekend motor, so it could have been stood a while, battery not getting used much?

I'll try and see what starter motor is on too, and see if it is original or one of the newer type.

[Alan.h]

when my car had water seal failure i had the same symtoms as you are describing take the plugs out and check them if the plugs are spotless clean that is a tell tale sign, i did put kseal in and it ran for 2 years with no further problems, till i had it rebuilt at RR

[spb2002]

when my car had water seal failure i had the same symtoms as you are describing take the plugs out and check them if the plugs are spotless clean that is a tell tale sign, i did put kseal in and it ran for 2 years with no further problems, till i had it rebuilt at RR

That doesn't sound too good?! Thanks Alan, i'll check that too!!

[GraemeC]

If the compression is only 4.7 on both rotors (as per the original for sale thread) this will likely magnify any other weakness re. starting

https://www.rx8ownersclub.co.uk/forum/v ... 4#p1229694

Did it start ok from hot and cold before the weekend?

[warpc0il]

Spinning the engine on the starter with the throttle floored is the (factory) recommended approach to clearing a flooded engine, but it does make everything worse in all other conditions.

- the engine can't fire with the throttle floored, since the fuel and ignition are shut off to de-flood.
- it takes a lot of power from the battery
- it can overheat the starter motor
- the OMP isn't shut off, so there's oil being injected into the cold chambers, which can foul the plugs and create a mess of smoke when the engine is finally started.

[spb2002]

If the compression is only 4.7 on both rotors (as per the original for sale thread) this will likely magnify any other weakness re. starting

https://www.rx8ownersclub.co.uk/forum/v ... 4#p1229694

Did it start ok from hot and cold before the weekend?

Morning Graeme, I figure it'll be down to the low compression, just trying to figure out in which area really. All last week started first time, hot or cold.
After work yesterday it started perfectly too. I've charged the battery overnight to be on the safe side, and started fine today as well.

I just need to figure out what happened over the three days it was sat.

[acegeezer]

Out of interest.. did you buy the car knowing low compression with a view to a rebuild?

[spb2002]

Out of interest.. did you buy the car knowing low compression with a view to a rebuild?

Hi Ace, yes I did... I've got some money put by, and I'll be adding to that for the rebuild

[warpc0il]

Just checking, do you rev the engine as you switch off?

Many people have seen YouTube vids and/or been told that "this is the switch off procedure" - either way, it's totally wrong.

When you just switch off the engine at idle, the PCM triggers the OMP to inject an extra boost of oil into the chambers. This coats the internal surfaces providing lubrication for the next cold start and , crucially, providing a film to assist the seals hold compression at starter speed revs.

If you rev the engine as you switch off, then this extra oil is just blown out the exhaust ports, where it is of no help the the engine and just blocks the cat.

The answer is the just switch the engine off as normal.

If you're already doing this then fine and the above is just interesting, otherwise we may have identified part of the problem.



Sent from my SM-G800F using Tapatalk

[spb2002]

Just checking, do you rev the engine as you switch off?

Many people have seen YouTube vids and/or been told that "this is the switch off procedure" - either way, it's totally wrong.

When you just switch off the engine at idle, the PCM triggers the OMP to inject an extra boost of oil into the chambers. This coats the internal surfaces providing lubrication for the next cold start and , crucially, providing a film to assist the seals hold compression at starter speed revs.

If you rev the engine as you switch off, then this extra oil is just blown out the exhaust ports, where it is of no help the the engine and just blocks the cat.

The answer is the just switch the engine off as normal.

If you're already doing this then fine and the above is just interesting, otherwise we may have identified part of the problem.



Sent from my SM-G800F using Tapatalk

I switched off as normal, but it was worth mentioning as I didn't realise this until I picked it up.... at first I thought I needed to raise the revs on all switch offs!

[mzivtins]

Its worth given the throttle body a look, its a 10second job, but sometimes the throttle plate gets jammed shut, this has all the signs of flooding but its just the worlds best choke lol

[PeteH]

Check the battery drain when the car is off. You only need a drain of about half an amp (6 watts) to make starting difficult after three days.

It's not uncommon to find some interior lights (especially boot) to stay on due to defective wiring or switches. Each bulb is around 6 watts.

Your drain should be no more than about 0.1 amps when the car is off.

[spb2002]

Check the battery drain when the car is off. You only need a drain of about half an amp (6 watts) to make starting difficult after three days.

It's not uncommon to find some interior lights (especially boot) to stay on due to defective wiring or switches. Each bulb is around 6 watts.

Your drain should be no more than about 0.1 amps when the car is off.

Cheers Pete, I'll check that, too.

[warpc0il]

https://www.rx8ownersclub.co.uk/forum/v ... 25&t=38133