93 5.0 MSPNP2 tuning ?s
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Drove to work this morning, didn't log anything was running late. But watching the wideband, I either didn't get the MAT/ CLT correction right (very likely), or the idle isn't dialed in correctly. Idle should be 13.7 on my tune. It consistently idled 12.6-12.7 this morning with MAT @ 145. Yesterday evening with a 160*+ MAT it was 13.7. So I guess I need to do some more adjusting. Really not sure if there a more scientific way of adjusting the MAT/CLT correction or just guessing on the percentage?
The only problem I see you running into [which you already are] is that we are now skewing the actual MAT correction at idle. Now we have evidence that even small changes to the MAT# [through the MATCLT correction] affects the correction made by the mat curve.
This is a work around to the problem of bad sensor placement.
I will be honest most guys just skew the MAT correction curve on the hot side, I dont do this but others will tell you its how to fix it. There is alot of controversy about this over on the MS forums, only problem is opinions are easy to come by but real solutions are not.
//rant//
-Dont make anymore fuel changes to the VE table.
-on the drive home change the blend % to 20 and see how this does.
I cant think of any other way to figure this out besides trial and error, unless we move the sensor.
This is a work around to the problem of bad sensor placement.
I will be honest most guys just skew the MAT correction curve on the hot side, I dont do this but others will tell you its how to fix it. There is alot of controversy about this over on the MS forums, only problem is opinions are easy to come by but real solutions are not.
//rant//
-Dont make anymore fuel changes to the VE table.
-on the drive home change the blend % to 20 and see how this does.
I cant think of any other way to figure this out besides trial and error, unless we move the sensor.
I should also note that your car jumps really high in rpm on startup,
Idle settings
Cranking pwm
-lower the pwm% when it's full warm
You are looking for the car to go 100-200 rpm above target on startup then level off
Idle settings
Cranking pwm
-lower the pwm% when it's full warm
You are looking for the car to go 100-200 rpm above target on startup then level off
Yes but if we constantly change both variables (ve and blend%) we may chase our tails.
Datalog will allow us to easily see the afr error % for both the 50% and 20% blend we are looking to get the error% delta down for all idle temps.
I think I figured out why the stock ecu doesn't seem to have this problem. The stock strategy uses the MAF sensor for air density to calculate fuel. And just uses the MAT to pull timing when it's high. So, MAF is another option to "fix" the heat issue. Not sure I want to do that right now though, just learning to tune SD.
Now if we can't get this to work well, I'll try moving the MAT to the inlet elbow. I can see that still being heat soaked at first start up being right above the header, but has other people done this without having to have any MAT/CLT correction?
Now if we can't get this to work well, I'll try moving the MAT to the inlet elbow. I can see that still being heat soaked at first start up being right above the header, but has other people done this without having to have any MAT/CLT correction?
yes, i did it with my old build with great results.
Newer maf sensors also have the MAT sensor built into them. I am currently running MAF strategy with the MAT sensor in the intake below my blower, this was necessary as the blower is PD and mounted directly to the manifold. besides the first start i have not tuned on it yet so i dont know how it will do with heat soak.
only other option you have is to enable EGO correction so it works at idle, it may work well for you since you have a stock cam.
in ego settings change...
-active above rpm = 800
-ego delay = 4
Hmmm.... I'm sure as with anything there is pros & cons. What cons would there be with using EGO correction for idle. And if I do try it, go ahead and zero out the MAT/CLT correction table again?
And was the "yes" in the first part of your reply in reference to moving the MAT sensor?
1: maybe, you would have to try both ways.. The only issue with using ego correction at idle is that it will sometimes cause a AFR swing, the sensor delay at idle is very high with a WBo2. what it reads may be up to a half second late.. the ecu does not know this and just corrects by what it see's. try it and report back, you can always change it back.
2: that was a yes in reference to the mat sensor. I was attempting to find a way for you to avoid having to modify your charge tube and wiring to move the sensor.
I'll try the EGO correction at idle and see what happens. Sounds easy enough to try.
I don't mind moving the sensor if it will work. Just thought I'd try seeing if I could tune around it. I guess technically, the MAT/CLT correction is just lying to the ecu, and would never be exact as it's just skewing the #s to be "good enough".
as far as skewing i will say yes. this table for all intents and purposes is meant for those who get the MAT reading in the intercooler of a turbo car or from the air box and not the intake manifold. it allows them to add a small percentage of the CLT to the mat to correct the reading as the air in the manifold will be hotter than the airbox, but not as much as the ford placement shows...
This is a much lesser issue with GM sensors/ sheet metal intakes/ composite [plastic] intakes...
I was hoping it'd eliminate my problem. Ha! I don't get off that easily.... I reactivated the MAT/CLT correction again. I messed with it some tonight. I'll see how far it's off when cold in the morning.
Yes I probably jumped the gun...
Sorry @a91what for skipping what you told me to try. I just had to see if it'd work.
Yes I probably jumped the gun...
Sorry @a91what for skipping what you told me to try. I just had to see if it'd work.
That is part of the learning process!
3-4% is way better than the 10% you were seeing. I would say as long as the car idles correctly dont chase your tail to much. If you didn't have the wideband would you even notice? Probably not.
3-4% is way better than the 10% you were seeing. I would say as long as the car idles correctly dont chase your tail to much. If you didn't have the wideband would you even notice? Probably not.
Hope you're not ticked off at me.... I do appreciate the advice!
Did you have to still use the MAT/CLT correction with the MAT sensor moved to the inlet?
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