- Turbo Boost page 2 of 6
I also purchased a Gunsen boost / vacuum gauge, this kind of verified the low boost, but when tested on a couple of other LC's I was a bit sceptical because the reading were much the same as mine, the gauge was cheap and might have been off calibration.
Now armed with my data logging equipment I had some real figures to play with.
This chart shows the MAP reading (absolute) seen by the ecu, as you can see there is not much happening above 0.4bar
This chart shows how the MAP pressures should behave, readings taken from a standard LC known to be working correctly, peaking at 0.7bar
So, why were my turbo's not producing enough boost pressure ?
Knackered turbo's ? ........maybe, but unlikely as they had both been replaced a few thousand miles before I bought the car.
Waste gate actuators ?......maybe, but at re-newal they would have been adjusted.
In-active boost solenoid ?.....Maybe, but I can't check this component without a tech1.
A few months later and I have myself a nice tech1.
When using the tech1 to activate the boost solenoid is supposed to be activate for 5 seconds and then switch off. The solenoid makes a fart like noise, but mine was a little intermittent, and after a few tries it seemed to work ok, I had'nt used the car for a few months because it was laid up during winter......perhaps just a glitch......it was a new solenoid fitted at the same time the std ecu was fitted.
Subsequent tests on the solenoid all checked out, 99% happy with the solenoid now.............
I'd been looking for a permanent boost gauge to replace the clock for some months, I could not find one withg a suitable dial face so I decided to make a new one myself.
A drive with this fitted once again confirms low boost level, ie max at 1.4bar absolute.
Next I start to look at the turbo wastegates and a browse in the manual reveals how these can be set up, but I need to apply an accurate 8psi +/- 0.25 psi to the actuator.
I can't use my compressor because the regulator does not hold low pressures very well. I need a low pressure regulator, then I need a better way of measuring the pressure before it goes into the actuator as although the regulator will hold a nice steady pressure I need to know what it is first.
Again Will Reeve helps me out here with a electronic pressure transducer, I had this checked for calibration at work (along with my gunsen gauge, which proves nearly ok), the transducer is spot on.