Governor / Speed limiter 2000 GMC 3500 5.7

[sameshirt]

I tried the search function but didn't see what I was looking for, maybe you can help me out? I have a 2000 GMC Savanna 3500 with a Thomas Minotaur 29 passenger body. 5.7L gas engine. It won't go more than 60 or 65 mph. Is the speed limited in the ecm where I could over ride it with a programmer, or is it an external governor of some sort?

[WARGEAR]

It’ll be limited in the ECM. Factory GM trucks used to be limited by the ECM to 100 mph. The bus manufacturer probably had the ECM reprogrammed for 65.

That being said does it accelerate all the way to 60mph and then even with your foot down drop off? If the RPMs drop once you hit 65 it’s a limiter. If the bus is just incapable of hitting 70 then you have a mechanical issue that needs addressing.

[Obxjeepman]

Did you ever figure out how to get rid of the speed limiter? I just bought a 2000 GMC Savana diesel and will only go 58 MPH. It runs with plenty of power until then.

[EastCoastCB]

Originally Posted by Obxjeepman

Did you ever figure out how to get rid of the speed limiter? I just bought a 2000 GMC Savana diesel and will only go 58 MPH. It runs with plenty of power until then.

what rpm is the engine turning at top speed?