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Can not rev past 4200


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96 ej22e

 

I know i have seen this issue on here before....but cant seem to find any fixes. I had a fuel line feed leak i thought he pressure drop might be the cause, replaced the line..no leaks..issue still there. Also at the same time I started to have idle issues. mpg's have dropped as well.

 

I have 1 code and its for my speedo. I had a code for coolant temp, but it went away when i cleared it. I have a new sensor in the box still.

 

I have a feeling my isv sticky/bad..but that wont cause what feel like a soft rev limit. My MAF is a reman and only 6-7 months old.

 

Any tips or things i should check?

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Manual or auto?

 

Auto goes into limp if you have speedo code.

 

Manual I would check your MAFS and TPS.

 

Thanks. Its a 5speed. I bet its tps. But I'll clean my MAF to see how that goes.

 

 

 

 

Sent from my VS920 4G using Tapatalk 2

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Ej222 and its stock ecu, from what I was reading this was one of the only cars that had speed density this model year (99 Brighton ).

 

And I know that with a MAF on certain cars, the thing wont run barely unless the MAF is all good.

 

Like I said, I just have a loose understanding of the 2 systems and how it manipulates the air to fuel and then like you said, seems it would barely have anything to do with that.

 

Just from your experience, what are some protocols moreso that I can take to make sure a map/sd system is working optimal.

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One thing with that, that is kind of peculiar is my friends miata. It was a MAF system until he went to a standalone with a Megasquirt 3 and that custom ecu required the use of a speed density system.

 

Aren't these systems supposed to be "inferior " to a MAF setup?

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Just so you guys know... last night I was able to rev out to redline without my speedo. Also felt some power too. It has to be a tps issue. I snagged a tb from a junk yard.

 

Going to clean it up and toss it on today to see how it is.

 

 

 

 

Sent from my VS920 4G using Tapatalk 2

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Subarus TPS's have to be adjusted when installing. The use of a scan tool with data capabilities will do the trick. Key On Engine Off (KOEO) it should have a reading of .70 volts with your foot OFF the gas petal. Just installing the new one where the old one was will get you close but they need to be dead on for everything to work right. You'll need a better scan tool as most will only show TPS % and it's better to have the volt data. GL

 

Speed Density systems are some what better for turbo engines as the MAF sensors will create a flow issue to the turbo unless a larger higher flow rated MAF can be found for the application. Plus it's one less thing you don't have to worry about fabing some piping to and from and it looks cleaner w/o them.

What they lack verse a MAF sensor is the ability to compensate for temp and elevation changes accurately. A MAF sensor measures the air flow in real time and can adjust where SD can only make changes from the preprogrammed values.

I ran a MAF Translator in my old Supra, which is a tuning system that changes from MAF to SD. The biggest headache was when I tuned it in spring it got warmer and more humid it would run like crap so I would have to retune it. Then again weather changed I would have to retune it. Being a piggyback system was a downfall in itself. Most standalone ECUs like AEM or Pro-Efi are better suited for using a SD system.

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Ahhh I see, thanks for that, as no one wanted to take the time to explain it to me.

 

That's why my buddy's miata has like 3 IATS and he has them averaged out at the different points in the engine bay so Megasquirt can recognize more realistic temps with that logarithm.

 

Obv from what you said it wouldn't be as accurate as MAF since the no air/density mixtures can bs the MAF since it has to go through it before being used for combustion.

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Right, MAFs read in real time and can adjust more accurately where SD uses preset values to compensate which in higher elevation or humid hotter weather the values might not be accurate and you could have running issues. Honda's are the perfect examples. My friend and I took his Del Sol to AZ and while driving through the mountains his car lost its power and ran like poop. It was a SD system from the factory. If it were to have a MAF sensors it would've ran with more power because it could adjust the air fuel mixture faster and accurately. Hope that explains a little better.
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