engine only revs to 3000 rpm?

[demolition man]

ok the ,y engine runs fine until it gets to 3000 rpm and then it feels like its hit a dead spot and wont rev any futher, but it operates perfectly fine until 3000. i think it could be A problem with my afm but im not sure, what are other things i should look into

 

[DegreE]

Any codes? Check the TPS and CPS.

 

[demolition man]

fixed it it was my airflow meter, one of the wires ripped out of the connector. ks guys

 

[jetjock]

Not surprising since 3000 is the programmed rev limit for a bad air flow input. It also means your TPS is working because if it wasn't the engine wouldn't have done that.

 

[Amontgomery]

Is that a pre-programmed "limp home mode"? I read about that setting one day and I was curious to know if that is the same thing.

 

[jetjock]

What you're calling limp mode is properly known as Fail Safe. When the airflow signal is abnormal the TCCS substitutes two values based on the TPS. One is for starting the engine (IDL contact on) and the other (IDL off) is for driving. That will get you about 3K max.

There's a bit more to it but you get the idea. It's why I'm always amused at those who say their engines won't start with the AFM unplugged. Fact is as long as everything else is working right in the EFI system you could start and drive it around all day long. I've done so on more than one occasion. Well, maybe not all day long...

 

[Amontgomery]

Thanks for the information.