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> MPS Adjustment, It helps to have the right tools
Mblizzard
post Sep 2 2014, 08:00 PM
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I post this only because I struggled to find the proper tools to adjust my MPS after going to a 2056. While I was able to make adjustments using standard tools, I could never get it exactly right. I asked several people about where I could get the right tools and could not find them. It is likely that this is well known to everyone but me, but I finally found what I needed at Tangerine Racing.

It is such a simple tool but without it you can't really be sure you are adjusting only one of the screws without changing the other one. So once again Chris is the man that can put the right tool in your hand. I have been close on the adjustment many times only to mess it up trying one more small change.

If you are playing with your MPS just get one of the MPS tuning kits from Chris it will make your life much easier.

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Brian_Boss
post Sep 3 2014, 08:08 PM
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If you don't have the exact RLC meter that Brad used ( I forget the brand and model but it is no longer made) the values he gives are really more of a guideline.

I have a pro quality meter but not the specific one he used and the L values needed some tweaking.
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Mblizzard
post Sep 3 2014, 09:04 PM
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QUOTE(Brian_Boss @ Sep 3 2014, 06:08 PM) *

If you don't have the exact RLC meter that Brad used ( I forget the brand and model but it is no longer made) the values he gives are really more of a guideline.

I have a pro quality meter but not the specific one he used and the L values needed some tweaking.


Brian,

Are you saying you can set up a MPS using values? I have been trying to do it to A/F meter readings. I have an extra MPS that I may want to have someone play with.
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Brian_Boss
post Sep 4 2014, 04:52 AM
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QUOTE(Mblizzard @ Sep 3 2014, 10:04 PM) *

QUOTE(Brian_Boss @ Sep 3 2014, 06:08 PM) *

If you don't have the exact RLC meter that Brad used ( I forget the brand and model but it is no longer made) the values he gives are really more of a guideline.

I have a pro quality meter but not the specific one he used and the L values needed some tweaking.


Brian,

Are you saying you can set up a MPS using values? I have been trying to do it to A/F meter readings. I have an extra MPS that I may want to have someone play with.


You can calibrate them using a meter that can measure inductance (usually called an RLC meter) and a hand vacuum pump. If the specs are not on Brad Anders web site, they are in an old post here.

The issue is that there appears to be some variation between meters. Unless you have the exact model Brad used, it will be a ball park setting. In my case, made the car driveable but needed fine tuning with a/f meter.

If you had a known good MPS, I'm pretty sure you could "copy" the calibration to another using any decent meter.

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JeffBowlsby
post Sep 4 2014, 02:34 PM
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There is more to it than that. Brad used a Wavetek LCR55 meter to develop his values...I agree with the above, I have found them to be lean, so I richen them up. The MPS calibration values are very delicate and significant A:F ratio changes can occur with only slight changes to the MPS. I have that same meter and have calibrated many MPS but have developed my own values, based on my location and the requirements of my personal 50KMI 2.0L. Values for your specific car will likely be different than mine. I also own a couple of NOS 043 MPS (Not for sale]...and guess what...their calibration is not identical to each other on the meter.

Be sure to index the calibration values to factor in changes in elevation from your location to Brads location in AZ, which affect atmospheric pressure as Brad describes on his webpage.

Even with that there are other variables - engine wear, timing, sensor variances, actual injector flow rates, barometric pressure differences due to local ambient weather, etc.

The published values should be close enough to get the car running, but the specific calibration needs fine tuning with an exhaust gas analyzer, WB02 or similar precision equipment to get it right on, due primarily to just too many variables with engines that are 40 years old. The old carb method of listen/drive/tune is laborious, but not impossible, just takes time. But there is a risk that if you don't understand or realize what changes you are making, with three different calibrations that are interrelated, you could potentially cause more damage and make things worse.
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