HELP !!! only getting 0.5 bar boost

[DavieBow]

Hi guys ,
i noticed today that i only get up to 0.5 bar boost on my gauge when i give it some ,
i understand that this is some sort of safety thing when the car is either cold or there is an underlying issue , how the hell do i find out what the underlying issue is without getting my pants pulled down by a dealership ?

[John_W]

Elanscan is your Elan's best friend.
If you don't have a mountain chip, the gauge showing 0.5 bar isn't unusual.
If it's not making full boost because of temperature issues, maybe the thermostat isn't closing. But Elanscan will point the way.

[DavieBow]

Mountain chip ordered

[lotusflasherman]

Hi guys ,
i noticed today that i only get up to 0.5 bar boost on my gauge when i give it some ,
i understand that this is some sort of safety thing when the car is either cold or there is an underlying issue , how the hell do i find out what the underlying issue is without getting my pants pulled down by a dealership ?

Download the Manuals here ...www.lotusm100.com/manuals/

Is yours SE (Open Loop) or S2 (Closed Loop) ? Some SE's have been converted to Closed Loop - Closed Loop has Lambda Sensor in the Turbo, Open Loop doesn't. Standard boost goes to 0.65 but there are constraints when engine not warm with info coming from Coolant Temp Sensor, which is independent of the gauge sender. CTS failure can cause bad fueling when hot so if that's not occurring it may be thermostat not getting engine warm enough for ECM to think full boost is suitable.

If Open Loop Turbo operation is EMK2, Section W (Page 40/178 in pdf) in this one ...www.lotusm100.com/manuals/Elan-M100-Engine-Management-Manual-v6.pdf

As John says Elanscan is a good diagnostic tool to give you the info, Manuals to interpret it and with help on this forum you probably won't need a dealership...

[Rice crispy]

Does it actually feel like it's down on power? The gauge isn't always accurate and the earth on the transducer on the drivers side inner wing can produce the results you are getting. The transducer is the thing with the rubber cover (usually orange)

[DavieBow]

Hi guys ,
i noticed today that i only get up to 0.5 bar boost on my gauge when i give it some ,
i understand that this is some sort of safety thing when the car is either cold or there is an underlying issue , how the hell do i find out what the underlying issue is without getting my pants pulled down by a dealership ?

Download the Manuals here ...www.lotusm100.com/manuals/

Is yours SE (Open Loop) or S2 (Closed Loop) ? Some SE's have been converted to Closed Loop - Closed Loop has Lambda Sensor in the Turbo, Open Loop doesn't. Standard boost goes to 0.65 but there are constraints when engine not warm with info coming from Coolant Temp Sensor, which is independent of the gauge sender. CTS failure can cause bad fueling when hot so if that's not occurring it may be thermostat not getting engine warm enough for ECM to think full boost is suitable.

If Open Loop Turbo operation is EMK2, Section W (Page 40/178 in pdf) in this one ...www.lotusm100.com/manuals/Elan-M100-Engine-Management-Manual-v6.pdf

As John says Elanscan is a good diagnostic tool to give you the info, Manuals to interpret it and with help on this forum you probably won't need a dealership...

Thanks Phil ,
mine's an SE but i'll have a check tomorrow to see if its been adapted to closed loop.
One thing i have noticed is its not even getting over the 1/4 mark on the temp gauge , could this be the down to a faulty CTS and/or thermostat do you think ?
I'm exchanging emails with Geoff for an Elanscan interface so when i get back from working away this week i'll be able to get her on the diagnostics and have a good look around

[Rice crispy]

Temp gauge isn't linear so normal running temp is between the bottom 2 marks and fans should kick in just before the 3/4 mark. Update your location as someone local may be able to loan a lead. Always good to have one though even if you have only used it a couple of times like me

[DavieBow]

Does it actually feel like it's down on power? The gauge isn't always accurate and the earth on the transducer on the drivers side inner wing can produce the results you are getting. The transducer is the thing with the rubber cover (usually orange)

it feels lively enough but i managed to get on a straight today and floored it in 3rd , it did seem to run out of juice about 3/4 up the revs but don't know if that was my imagination because the boost wasn't getting any higher at that point

[Rice crispy]

Mine pulls all the way to redline if I hold the gear. Does it feel the same in other gears? You could check the wastegate as well as that could be sticking. Have a search for wastegate wiggle

[DavieBow]

I'll see if I can have a bit more of a play tomorrow and go through the gears a bit and see what I notice

[lotusflasherman]

Thanks Phil ,
mine's an SE but i'll have a check tomorrow to see if its been adapted to closed loop.
One thing i have noticed is its not even getting over the 1/4 mark on the temp gauge, could this be the down to a faulty CTS and/or thermostat do you think ?
I'm exchanging emails with Geoff for an Elanscan interface so when i get back from working away this week i'll be able to get her on the diagnostics and have a good look around

Temperature gauge and sender is separate from Coolant Temp Sensor, which is another thermistor close to TG sender. CTS sends info to ECU. ECU restricts boost to 0.5 bar till engine gets above 50°C based on info from CTS. 1/4 mark on the Temp gauge is 75°and halfway to it is 53°so not obvious why you are not getting full boost to .65 bar. Could try pulling wire off CTS and replacing in case bit of corrosion is giving artificially higher resistance. CTS should be 7.5k ohm at 4°C incrementing down to 185 ohms at 100°. Failure of the CTS will produce a Code 14 or 15 on the Check Engine Light if it, or the wiring to it, goes short circuit or open circuit respectively.

If you want to try a new thermostat, I use one of these 89°C thermostats. www.ebay.co.uk/itm/VAUXHALL-ASTRA-1-7-DTI-16V-1-7-CDTI-16V-00-10-Replacement-Thermostat-/400593866420

It has the required 'jiggle pin valve' (fit with valve at 12'o clock) and keeps the engine, and oil, at a nice working temperature. Use my Elan all year and a heater than works and clears the windscreen quickly is much appreciated... (Can't reach the bloody thing to wipe it ... )

[lotusflasherman]

the earth on the transducer on the drivers side inner wing can produce the results you are getting.

Nope. Bad earth gives Full Scale on Boost gauge ....forum.lotuselancentral.com/viewtopic.php?f=31&t=24504#p308387

Been there, got the T shirt ...