Thread: Engine cutting out at exactly 4500 rpm (acts like a rev limiter?)

My VE is breaking up, in any gear, under light or heavy load, light throttle to heavy throttle, at precisely 4500 rpms. No codes. It feels and acts like a rev limiter. There is no going past 4500 no matter how hard I try. My SA ecu is set to 7500 rpm rev limit. Any ideas?

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Speedometer is not connected at the moment, could this be a possible cause?

Hmmm... the launch control feature on the SA is set to 4500... and part of it is based on speed related factors... I don't think it's enabled, but gonna go up the limit and reflash the ECU and see what happens...

edit: reflashed with 8000 launch limit, no change in behavior

You're hitting launch control limit because the ECU isn't seeing speed.

Reconnect your sensor.

I'll rewire the connector, but I've just changed the launch control limit to 8k and it's still occurring.

Just wanted to bump this thread -

Initially, changing the launch to 8000 did not help the issue. However, it seemed to work after a couple run cycles. I fixed the speedometer after that, but it's still strange to me that the changes I made to the ECU did not kick in immediately. At this point the original issue has been fixed, so I'm talking solely about the delayed update issue now. Yesterday I changed the launch limiter back down to 4500, after which I immediately tested it. It did not activate at 4500. Turn off the car, try it again.. nope. Drove around a bit yesterday, turned the car on/off a couple times while I was out, and came back and let the car sit overnight. Forgot about it until I got to work in the morning today, and wanted to see if it would work.... took it up to 4500 and bam the limiter kicked in. It seems to me the ECU, after reflashing, does not take this specific limiter change into effect immediately.

Things like changing the launch limiter stuff seem to need to be done with ecu powered down, and using upload base, upload changes definatly does not work for changes to items like that for some reason.

maybe this sounds dumb but, I had a problem similiar and was the spark plugs

Very good to know. Thanks.