Cold engine start procedure

[zadumbreion]

I have been advised - when starting a cold engine - to blip the throttle a few times to about 3,000 revs. Can't remember the reason given - to clear something out, I think - otherwise it can idle too fast apparently.

Does this make any sense to anyone and if so, please explain!

[slideways]

dont do it. let it warm up and i wouldnt take it over 2000rpm untill its up to temp if it idles high leave it ,it should calm down after a bit

[Colin L]

Ah instruction on how to blow up a Speed 6 finally handed down to the RV8.

NO NO NO, blip the throttle only if she is about to stall, she should never be bliped over 2000 - 2500, mind you a quick blip over 3000 will not do any harm as long as its a quick one of blip..


Colin L

[zadumbreion]

It does feel wrong to do so - and when it's completely cold, of course, the cylinders aren't all firing so the blips feel very rough, along with a puff of blue smoke behind the car. Having said that, the car then settles down to a nice clean idle...

[Slikk]

1. Enter garage and start car without touching the throttle.
2. Go back indoors and have a cup of tea.
3. Go for a drive.

Edited by Slikk on Monday 11th February 09:37

[Johno]

Slikk said:

1. Enter garage and start car without touching the throttle.
2. Go back indoors and have a cup of tea.
3. Go for a drive.

Edited by Slikk on Monday 11th February 09:37

Secure in the knowledge that your cam is wearing out as the load on the lobes at idle is the highest at any point of the rev range and supply of oil at it's lowest .. .

Finish your cuppa and then whilst driving you can puzzle at the lack of performance your cars appears to have developed . . .

Go to garage, start car, get it out of garage, close garage door, get in, buckle up and use it. Do not take it above 3k until you have reached normal operating temps . . .

All this warming up advice is often misleading, get in it and drive it with the appropriate mechanical sympathy and you'll do far less damage than leaving it sitting around idling . ..

Edited by Johno on Monday 11th February 10:55

[Johno]

zadumbreion said:

It does feel wrong to do so - and when it's completely cold, of course, the cylinders aren't all firing so the blips feel very rough, along with a puff of blue smoke behind the car. Having said that, the car then settles down to a nice clean idle...

If all the clinders aren't firing you need to find out why, injectors, plugs, plug leads . . . It should b firing on all 8 and not waiting for the temp t increase to help ignitiing th charge. The ECU doesn't pick which cyclinders to fire, it is a fault.

It is common, and mine does it as well, but it doesn't make it right

[Chim Chim Cheree]

At cold start the ECU does big overfueling for a short while. If you stall at this time, you could well flood. It's only for a few seconds, up to a minute.

As Johno says, it indicates a problem. Mine does it as well, and I'm going to investigate soon. Most likely a weak spark. My leads look old, so I'll look there first, if that's any help.

What I do is
get in car.
Start it.
Once fired, hold throttle to 1500 - 2000 rpm until it runs smooth. About 10 - 20 secs. This avoids stall/flood, and reduces the dreaded lobe load mentioned above (i think. I'm no engineer!)
Exit garage. Drive. Not over 2.5 - 3k RPM until well after temp is up. The oil takes longer to heat than the water.

Hopefully I can reduce all that starting malarky when I change my leads/etc. but at the moment I kinda like it. Makes me feel involved with the car. It also gives the neighbours a chance to savour the sweet music for a while longer...

So, you're all normal. Hope the above helps.

[Aubrey]

I start mine and take the cover off, and put in the boot (I don't have a garage!) then get in and drive off slowly. It has maybe 10-20 seconds to settle to a steady idle, but I'm wary of not leaving it to idle for several minutes. It feels rough for the first few miles at about 1500rpm, it sometimes feels like it will stall when reversing etc and the revs dip to 300-400, but with a little throttle, they bounce back up again. Between 1500 and 3000 it is fine, I don't go above 3000 til its fully warm. Even if it does mean getting overtaken by someone on the way to work! Grr

[zadumbreion]

And they take a while to warm up fully don't they?? Hard to tell properly with only a water temperature gauge, but I reckon it must be a good 15 minutes.

How long do you guys give it to warm up?

[zadumbreion]

Johno said:

zadumbreion said:

It does feel wrong to do so - and when it's completely cold, of course, the cylinders aren't all firing so the blips feel very rough, along with a puff of blue smoke behind the car. Having said that, the car then settles down to a nice clean idle...

If all the clinders aren't firing you need to find out why, injectors, plugs, plug leads . . . It should b firing on all 8 and not waiting for the temp t increase to help ignitiing th charge. The ECU doesn't pick which cyclinders to fire, it is a fault.

It is common, and mine does it as well, but it doesn't make it right

I would expect most engines to grumble a bit when cold though - I think the Alpina starts off a little rough as well for the first minute or so. I agree that technically it probably is a fault. Could be something like a little fuel having leaked into a cylinder or something - in other words it doesn't need the engine to warm up to fix, just a few engine revolutions to clear out some crap?

[Johno]

I agree, that's why I don't panic about it, you've gotta get fuel pressure up etc . .

Gut feel tells me it is a the injectors not atomising the fuel enough making the charge harder to ignite, combine with some moisture build up and a weaker spark and until it's warmed up a little then it'll be a problem . .

I also tend to hold the throttle for 10-15 seconds to clear through. Interestingly though, when I used it everyday I didn't have this problem . .

[WazzaL]

I have a similar intermittent problem in the cold or very damp conditions.

Start car, car springs into life... Engine dies / stalls... Car won't start, and I have to spend ages trying to get it to start again but is very rough for a minute or so.

Suggestions?

[Aubrey]

WazzaL said:

I have a similar intermittent problem in the cold or very damp conditions.

Start car, car springs into life... Engine dies / stalls... Car won't start, and I have to spend ages trying to get it to start again but is very rough for a minute or so.

Suggestions?

I've had this with previous cars, prob different with TVRs though, maybe try cleaning stepper, plenum etc? Maybe try holding throttle at 1500rpm when you start it? Might prevent the stall?

[Al 450]

Aubrey said:

WazzaL said:

I have a similar intermittent problem in the cold or very damp conditions.

Start car, car springs into life... Engine dies / stalls... Car won't start, and I have to spend ages trying to get it to start again but is very rough for a minute or so.

Suggestions?

I've had this with previous cars, prob different with TVRs though, maybe try cleaning stepper, plenum etc? Maybe try holding throttle at 1500rpm when you start it? Might prevent the stall?

My car overfuels when cold for about the first 30 secs, any throttle then will stall and flood the engine. After 30 secs the revs rise very slightly then settle down to 7-800. I then drive away keeping revs below 2500 as mentioned.

[saddpj]

Reading the entries above, I think that I must have a very serious problem!!!!!

1 Open garage
2 Disconnect Accumate
3 Deactivate immobiliser
4 Turn key in ignition and wait for fuel system to pressurise
5 Start engine and it fires on all 8 cylinders almost immediately and ticks over beautifully (Definitely something wrong there: it won't misfire, it won't stall and the exhaust is clean)
6 Exit garage
7 Close garage
8 Drive away, max 2.5k revs for ten miles at which time all is extremely well.

Any help gratefully received!!

Foggy

[slideways]

saddpj said:

Reading the entries above, I think that I must have a very serious problem!!!!!

1 Open garage
2 Disconnect Accumate
3 Deactivate immobiliser
4 Turn key in ignition and wait for fuel system to pressurise
5 Start engine and it fires on all 8 cylinders almost immediately and ticks over beautifully (Definitely something wrong there: it won't misfire, it won't stall and the exhaust is clean)
6 Exit garage
7 Close garage
8 Drive away, max 2.5k revs for ten miles at which time all is extremely well.

Any help gratefully received!!

Foggy

Christ alive you've got a serious problem there me thinks,under no circumstances should you drive the car whilest it is showing those symptoms,get it down to your local grease monkey asap so he can throw a spanner in the works

[nikman]

saddpj said:

Reading the entries above, I think that I must have a very serious problem!!!!!

1 Open garage
2 Disconnect Accumate
3 Deactivate immobiliser
4 Turn key in ignition and wait for fuel system to pressurise
5 Start engine and it fires on all 8 cylinders almost immediately and ticks over beautifully (Definitely something wrong there: it won't misfire, it won't stall and the exhaust is clean)
6 Exit garage
7 Close garage
8 Drive away, max 2.5k revs for ten miles at which time all is extremely well.

Any help gratefully received!!

Foggy

That's funny Foggy - my 450 seems to behave exactly as yours Must've been put together by the same bloke

But would someone please tell me what this lobe load is. Spend...? Anyone...?

[jdharris]

zadumbreion said:

I have been advised - when starting a cold engine - to blip the throttle a few times to about 3,000 revs. Can't remember the reason given - to clear something out, I think - otherwise it can idle too fast apparently.

Does this make any sense to anyone and if so, please explain!

This is to clear out the Cat (not the moggy!). I was advised to do this by Fernhurst when I bought my Chim. I believe their exact words were "brum, brum". Nothing more, nothing less - just a couple of quick blips to blow out all the crap that settles in the Cat when the engine stops. In case you're wondering what comes out, they have a board at Fernies that the owner makes them put behind the cars in the show room because he's sick of painting the walls!

[zadumbreion]

jdharris said:

zadumbreion said:

I have been advised - when starting a cold engine - to blip the throttle a few times to about 3,000 revs. Can't remember the reason given - to clear something out, I think - otherwise it can idle too fast apparently.

Does this make any sense to anyone and if so, please explain!

This is to clear out the Cat (not the moggy!). I was advised to do this by Fernhurst when I bought my Chim. I believe their exact words were "brum, brum". Nothing more, nothing less - just a couple of quick blips to blow out all the crap that settles in the Cat when the engine stops. In case you're wondering what comes out, they have a board at Fernies that the owner makes them put behind the cars in the show room because he's sick of painting the walls!

You're right, it was to clear out the cats. And it was Fernhurst that told me to do this.