Rev limiter

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Dropped88

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I bet it still doesn't go high enough to hurt itself. :Big Laugh:

Well not a proud moment but the 454 in my 92 tick me off in the beginning so it got twisted hard. And all it did was a loud lean pop through intake.

So I figure the ignition system will run out before any engine damage
 

Schurkey

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My '88 K1500 has no tach. No idea about RPM. How accurate is the speedo? At "normal" speeds, it reads about 3--5 mph low, probably due to tire diameter.

It would send the white part of the speedo indicator around the dial, off the end of the scale, and then the clear part would come around again to 10 or 20 mph; and didn't seem like that was the actual top speed. It was just as far as I was willing to go.

But I haven't done that for more than seven years.

A guy I worked with won a fairly-large Lottery prize. Bought the wife some jewelry, bought himself a Vortec 5.7L pickup. He hit the speed limiter while I was leaving him in the dust. His truck had more horsepower 'n' torque than mine...but what good is power if the computer won't let you use it?
 
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VIKING_MECHANIC

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Since we're on the subject of rev limiters (and fuel cut off), on 96+ gmt400s, how is the fuel cut off activated? Is it mechanical or is it hardwired into the ecm. And how would one go about in deleting/adjusting the threshold?

Asking for a friend...
 

df2x4

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Since we're on the subject of rev limiters (and fuel cut off), on 96+ gmt400s, how is the fuel cut off activated? Is it mechanical or is it hardwired into the ecm. And how would one go about in deleting/adjusting the threshold?

Asking for a friend...

Assuming you're referring to the 98MPH limiter, it's in the PCM tune. You need tuning software like JET DST ('96+) or HPTuners ('98+ only) to modify it. Either that or have one of the mail order tuners like Black Bear Performance do it, they did so on my red '97.

I'm not sure if it can be removed entirely, but you can set the MPH threshold so high that it'll never happen. FWIU it should be a very simple parameter to change with the correct software but I've never done it myself. Been thinking about buying JET DST so I can mess with things like this.
 

Caman96

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When BlackBear did my pcm, they asked if I wanted it removed. Yes it’s still there, but I haven’t noticed it.
 
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