View Full Version : Dawes Settings and Altitude
Snow Patrol
25th January 2017, 11:48 AM
I live at about 900m above sea level and have my Dawes valve set to about 16 psi. I notice when I go down to the coast that reading will increase to as much as 18 to 19 psi. Now I know that atmospheric pressure is greater at the coast causing the increase and I have to stop and wind back the Dawes about half a turn which gets it back to acceptable levels. I have experienced an over boost engine code on the odd occasion I don't do this. Car performs well at home at my original setting. I also noticed that egts are down a lot further at the coast.
I guess what I am asking is there an easier way to do this or do I have to re tune every trip to lower altitudes.
threedogs
25th January 2017, 03:50 PM
18-19 psi is not high for the ZD30 Di motor, Im running 20ish
with no problems.
Leave it as is unless its going into limp mode??
Snow Patrol
25th January 2017, 05:14 PM
Yeah it did go into limp yesterday. I should have mentioned its a CRD.
threedogs
26th January 2017, 12:58 PM
Yeah it did go into limp yesterday. I should have mentioned its a CRD.
Maybe back the dawes off a touch to avoid limp mode and see how that goes
have you blocked the EGR?
mudski
26th January 2017, 10:26 PM
Time to look up the "how to" maf voltage mod. Then say bye bye to limp mode.
Snow Patrol
27th January 2017, 11:28 AM
Maybe back the dawes off a touch to avoid limp mode and see how that goes
have you blocked the EGR?
Yep that's all done. Beginning to think now I may have a leak somewhere. Can't seem to get boost back over 15 psi. Will have to investigate. Intercooler was recently replaced btw.
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threedogs
27th January 2017, 11:48 AM
Yep that's all done. Beginning to think now I may have a leak somewhere. Can't seem to get boost back over 15 psi. Will have to investigate. Intercooler was recently replaced btw.
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I take it you replaced it with a fully tigged and tested unit?
Check/or replace your vacuum hoses maybe they are perished
and leaking,
Snow Patrol
31st January 2017, 03:37 PM
I take it you replaced it with a fully tigged and tested unit?
Check/or replace your vacuum hoses maybe they are perished
and leaking,
Checked all the hoses all good. Nipped up the turbo hose clamps as well. Some were a tiny bit slack. Anyway the news is good. Pressure is back up about 18 psi. Could have been a very small pressure leak coupled with some very hot days keeping the pressure down. Good now though.
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threedogs
31st January 2017, 04:59 PM
Checked all the hoses all good. Nipped up the turbo hose clamps as well. Some were a tiny bit slack. Anyway the news is good. Pressure is back up about 18 psi. Could have been a very small pressure leak coupled with some very hot days keeping the pressure down. Good now though.
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If your IC is oily chances are its leaking, you could test it but really they all leak
very early in their life
Snow Patrol
31st January 2017, 05:10 PM
If your IC is oily chances are its leaking, you could test it but really they all leak
very early in their life
Its a tigged one. I replaced it about 10K ago. But it was leaking.
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threedogs
1st February 2017, 04:10 PM
Best thing you can do next is to buy yourself a Scan Gauge, that way you can monitor
whats happening under the bonnet and re set any error codes that may pop up.
Best bit of kit for any CRD motor
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