MSExtra M20 Turbo high rpm hesitation help please.

[cheek]

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[Q5Quint]

See if you can post a imgur link or something for the log files.

What you are describing could be many things, and the work you did to the car could be a culprit, or not.

Possible issues to check:

I had issues running rich + spark blowout under boost once my plugs were about 6 months old. New plugs would fix the hesitation. But it was a bucking/hesitation.

Feeling flat but still accelerating, not hesitating, could be a timing retard event happening for some reason. Could be overboost, could be temp sensor, could be several things.

I usually set mine for around 5k rpm for the 'soft cut' timing retard rev limiter before the hard cut at 6k while I am starting boost tunes to keep myself from blowing things up. Make sure your soft cut settings are not similar~ you may have never noticed it before but with the work you did and the timing getting off slightly you can feel them more now... but the cam going backwards 3 degrees and making it better is confusing... the slight knock you hear now would make sense.

Where I get really confused is the grounding issues moving the hesitation up 500-1000rpm. If you have a coolant sensor that is not grounding properly at higher rpms, and it is telling your ms that the engine is cold (or hot), causing a soft cut timing retard to happen... that could explain the issue. The work you did replacing the head gasket might have disturbed the grounding connection, and the wiggle in your logs for the sensor might attribute to this.

Fun eh?

My car was hesitating and cutting off randomly- so I replaced the stock ecu with a pnp ms from whodwho and it runs perfectly now. A cracked circuit board that disconnects under vibration could hurt either ecu. Goodluck and try imgur or something to link some pics of your tune. Curious about you timing settings and map, and the soft cut rev limits.

[cheek]

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[SLEEPYDUB]

OP have you found a solution to your problem?

[kyleconstantine]

Hey one easy thing to check is the crank position sensor gap...i was having issues reving past 5k because my gap was too large. Ms is way more fickle than the stock ecu. Should be 1mm between the cps and the toothed wheel....a us dime can be used if you dont have feeler gagues.

[SLEEPYDUB]

Hey one easy thing to check is the crank position sensor gap...i was having issues reving past 5k because my gap was too large. Ms is way more fickle than the stock ecu. Should be 1mm between the cps and the toothed wheel....a us dime can be used if you dont have feeler gagues.

I will adjust mine, but i have logged several runs with MS and have not seen any loss of signal from the crank sensor