Check Engine Light @ cold engine and turbo boost

[LE422]

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[Enright]

Welcome aboard (from us, although probably not from your Elan)!

Excuse me if you know this already, and sorry for being an old nag, but it's never a brilliant idea to rev the spuds off any engine from cold - especially a 20 year old one with a turbo!
They don't mind a good thrashing, in fact they thrive on it, but for the sake of mechanical sympathy they should be allowed a bit of leniency while getting up to operating temperature, and then allowed to cool down at the end of the journey rather than simply stopped from hot.
The oil adverts will tell you that maximum wear and damage to an engine is caused/suffered within the first few seconds after startup, before oil has had chance to circulate and get up to pressure, and therefore lubricate bearing and metal to metal surfaces.
Likewise, the turbo spins at up to 180,000rpm. It doesn't stop instantly but gradually spools down - unlike the engine itself. If you stop the engine while the turbo's still going at high speed, it literally cooks the now stationary oil in the turbo bearings, then runs dry and it turns it into carbon-based grinding-paste. Next stop, a (very expensive) turbo re-build. Far better to let it idle for a minute after a good thraping before stopping it.

As for the Check Engine Light, if you go and look up "ALDL" in the WikiLEC section from the link just below the page banner, or do a search for "paperclip" (all will become clear the more you research why), then you can see how to do your own fault code diagnosis.

Put your location in your profile - you're likely to find someone local on here who you can get valuable tips from, and let's see some pics of your car and hear about what brought you into the fold!

[Fredjohn]

Welcome to LEC and many happy years Elan driving ,we hope!! You'll find tons of help and advice on here and someone somewhere is likely to have a solution to your problems as most people have experienced them at some time or other.

An engine should never be revved hard from cold, always allow it to warm up. The Elan ECU has a safety setting which prevents the turbo operating below a certain temperature: the engine has to warm up before it will spin. Can't remember what it is, but you may have been lucky and this may have prevented your turbo from operating when you revved the engine to 6000rpm.

By the way, the boost gauge does not read when the car is stationary, it has to be moving to register boost.

[Enright]

A couple of very good points there - if you were simply trying to get a response out of the boost gauge, then doing it at a standstill WILL be fruitless, as the engine has to be under load. Even first gear is despatched with so quickly that unless you're on an uphill section it's almost a case of "blink and you'll miss it"! Higher gears are much better for testing boost limits, and Elanscan is even better than that because the boost gauge is a) notoriously unreliable, and b) due to it's unfortunate placement, right in your peripheral vision at the exact time that you really ought to be looking where you're going! , , .

Fredjohn's also right about the ECU limiting your fun from cold, although to clarify: the turbo WILL still spin because it's mechanically forced to by the exhaust gases. However, when the engine is cold, the ECU will control the Boost Solenoid Valve and therefore the wastegate to limit the available boost. You still get passive boost to about 0.4 bar, but there's a temperature level that has to be exceeded before the safeties are all taken off and the fun can really start (I can't remember what that is offhand but I'm sure someone will be along shortly to fill in the gaps in my memory)!

[Fredjohn]

Thanks Neil, wondered how the temp safety worked!

[Brit-Car-Nut]

Fredjohn's also right about the ECU limiting your fun from cold, although to clarify: the turbo WILL still spin because it's mechanically forced to by the exhaust gases. However, when the engine is cold, the ECU will control the Boost Solenoid Valve and therefore the wastegate to limit the available boost. You still get passive boost to about 0.4 bar, but there's a temperature level that has to be exceeded before the safeties are all taken off and the fun can really start (I can't remember what that is offhand but I'm sure someone will be along shortly to fill in the gaps in my memory)!

Just a thought: If the boost control has been by-passed with a manual boost controller, the safety system built into the electronics will not work.

He just bought the car so doesn't know what has been done in the past. He should dig out the workshop manuals and make sure things weren't altered as well as checking the error code to see what the system is complaining about.

ALL of the manuals are available at the top of the page under the heading "Manuals" as well as at www.lotusm100.com/manuals if you want them RIGHT NOW.

[Enright]

Thanks Fredjohn, and that's ANOTHER really good point that John makes.
It would be lovely if we could definitively say that Manual Boost Controllers and Fuel Cut Defenders (like the BBR kit) had been consigned to history with the advent and subsequent development of ESM's Mountain Chips. But unfortunately there may still be some lurking about out there.

If you can find any reference to MBC's, FCD's or bleed valves in your car's documentation, then trace the damned things and get them out of it! They are a ticking timebomb that sooner or later WILL result in the expiry of your engine.
They bypass many of Lotus's originally pretty sophisticated safety features, and fool the engine and turbo system into being able to run unlimited boost, with potentially disastrous consequences.

I think it's fairly safe to say that as far as engine trickery is concerned, ONLY ESM's range of Mountain Chips are designed to work in conjunction with the built-in safety features, and the provisos for these are clearly stated on his website (again see link above). It's a really good read anyway and personally I find it very entertaining and highly educational - but then I am a bit sad like that!!!

[LE422]

Thanks @ all for the valuable input. I think i got the message now. Will send pics soon!