Strange and dangerous problem
11-24-2020, 03:08 AM
#1
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Join Date: Dec 2019
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ivetech engine modle petrol year 2018
Strange and dangerous problem
Car has been running perfect and it did something very strange today.
Outside temp was 48* and thats the coldest it has been since I did some inter cooler work,more boost,15 psi "normal reading", and new tune. Got on it hard and wound it up good to see what the IAT was going to be after the inter cooler work and car lost power all of a sudden. AFR showed 19.1
Was at 10.5 then instantly shot to 19.1...melt down AFR for sure !!! and lost power of course. Tried it again real quick and same thing. So this is what I do know. IAT was at it's lowest 80* so my work payed off.
Fuel pressure https://100001.onl/ https://1921681254.mx/ was at 75 and holding and the gauge did register vacuum in the parking lot at work so thinking MAP sensor is good, but....could it be possible the boost hit the limp mode threshold ? That's the only thing I was not watching and I do not know what limp mode would do in an over boost condition.
Long story short now I can not duplicate the problem and it's back to normal but it is also 80* again outside.
This is a sure fire way to blow an engine and glad I have a real time wide band in it. Any ideas ??
Outside temp was 48* and thats the coldest it has been since I did some inter cooler work,more boost,15 psi "normal reading", and new tune. Got on it hard and wound it up good to see what the IAT was going to be after the inter cooler work and car lost power all of a sudden. AFR showed 19.1
Was at 10.5 then instantly shot to 19.1...melt down AFR for sure !!! and lost power of course. Tried it again real quick and same thing. So this is what I do know. IAT was at it's lowest 80* so my work payed off.Fuel pressure https://100001.onl/ https://1921681254.mx/ was at 75 and holding and the gauge did register vacuum in the parking lot at work so thinking MAP sensor is good, but....could it be possible the boost hit the limp mode threshold ? That's the only thing I was not watching and I do not know what limp mode would do in an over boost condition.Long story short now I can not duplicate the problem and it's back to normal but it is also 80* again outside.
This is a sure fire way to blow an engine and glad I have a real time wide band in it. Any ideas ??
11-25-2020, 05:25 PM
#3
Super Member
Yip definitely this. I have had it plenty. Can trigger it easily with the shift from 3rd to 4th gear. In fact I finally got round to ordering my map clamp today to resolve this issue. Oh yes its usually triggered at +17psi. Amazingly though some tuned 55' boosting over 17psi don't run into this limp, I'm yet to discover why, other than assume different year models didn't have this limp mode built into the ecu.
