05-05-2012, 07:18 AM #1
- Join Date
- Feb 2008
MSX110/150 Boost pressure test port
I been getting alot of these MSX's in for repair lately, all with the usual problem of either over-boost alarm or not reaching full RPM
I have digital wrench but this is of limited use. It will show what faults are are stored (active or historic). But how do you prove the engine is actually over boosting or there is not enough boost pressure.
I decided to install a simple but very effective test port that will allow me check the actual boost pressure and allow me to adjust the wastegate to control the correct boost @ WOT.
This port has proven invaluable in test these problemmatic machines.
As you can see from the photo's below it is a very simple install and can be carried out with the intercooler in situ.
Firstly i remove the aluminium intake pipe between the intercooler and the throttle body (ETB). I normally cover the ETB inlet to prevent anything getting in there.
I then stuff a rag into the outlet of the intercooler beyond the point where I am going to drill the install hole. This rag will prevent alu filings from getting into the intercooler and later maybe into the engine itself.
I then bore 11mm hole in the outlet pipe of the intercooler, ensure to bore the hole far enough back to allow the rubber joint of the removed pipe to fit correctly after install. Now using a small needle file I chamfer the edges of the hole I have bored, both inside and out, this is necessary as the sharp edges of the hole can tear the rubber of the install valve.
Now what I have been using as the test port is a tubeless tyre valve, available at any tyre center for a few cents. I pass it into the opening of the intercooler and up through the hole I have bored. I then stretch the valve with a pliers until it snaps into place ( some grease around the valve base helps install).
I then remove the rag carefully and discard all the metal filings. At this stage I normally start the engine and blip the throttle to get the turbo pressure to blow out any filings that may be left.
Now all back together and port is ready to use.
My test rig consists of a digital pressure gauge, hoses and fitting from my fuel pressure test kit. NOTE: an analogue gauge will prob be a better option as when water testing it is a lot easier to read running flat out on the water.
Some of you guys may have an easier or better option for an install so please let us know if there is. This one works good for me as my pressure test kit contained all I needed.
05-05-2012, 07:23 AM #2
05-06-2012, 05:01 AM #3
Never would have thought of that idea, I guess that is the benefit of these forums. Thanks for sharing
An alternative if you wanted a screw type fitting ( and I have never tried it) would be to drill and tap the pad that is just a little further down, the one that looks like where the MAP sensor was originally going to be located.
05-07-2012, 06:04 PM #4
- Join Date
- Apr 2010
- Stamford CT
Ditto, I would have never thought of this idea. I like it as once it is done, there is a permanent test port available. I found it fairly easy to tee into the vacuum/boost line that runs to the bov valve or fuel pressure regulator using a mechanical automotive boost gauge.
05-11-2012, 01:53 PM #5
but your idea is fully functional. the one advantage with a gauge taken from the vacuum/boost line as ride04msx said is that the boost pressure is taken at the last point of intake (ie from the inlet manifold) if you had a boost leak after the throttle body with your take-off might not be evident. i think this is why their is a map sensor both sides of the throttle body to detect even boosts.??? just a theory.
also i recomend testing every msx charge cooler, as mine had a huge leak on the left hand side (the circular flange) and the turbo just worked harder to keep pressures up. obviously turbo failed soon after.
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