last night my automatic z28 went into limp mode. i got in it and stupidly did about a 2800 rpm nuetral drop then the car would only drive in 3rd gear and wouldnt shift into overdrive. it would go into first and second if i manualy shifted it. i thought i messed up the tranny but today i got in it and everything was fine. yesterday the check engine light came on but today its gone. this car is basically stock all it has is K&N cold air and a flowmaster. anyone got any ideas as to why it did that?

 

Did you scan it for codes, to see why the SES light was on?

I doubt that the fact the PCM wouldn't put the tranny into anything other than 3rd or O/D indicates the PCM was in "limp mode".

 

This MAY be what happened to your car.
The OBD1 cars have some VSS diagnostics in the PCM that could do that if there was too great a mismatch of the RPM/ VSS or converter slip and it plagued racers with higher stall converters for a while until some of the tuners found out how to get rid of it. It caused a 1-3 shift at the drag strip - but not sure if it was sustained after the run was over.

Neutral dumps are AWFUL for your car - never do them again, ever, or your next post will be "Why won't my car move"

 

Exactly what happens when there is a VSS error (DTC 72). Don't do that to your transmission.

 

just out of curiosity, my 93 is the first manual I've owned and i was just curious if its real bad to dump the clutch on a manual, not trying to steal the post, I hope your question was answered just thought i would slip that in since it was on the topic

 

i dont think a 2800 rpm drop would hurt it. i' used to do some nasty drops from 4000 rpm into drive in my exploder. it still ran until the lease was over, but it sure sounded brutal

 

Generally not a good idea to "hijack" someone else's thread, particularly when you're asking about a manual tranny, and he's working with an automatic. Best thing to do is start your own thread.

 

Yes I'm sorry. It appeared that his question had been answered and instead of wasting a new post on a dumb question around the same topic just thought it wouldn't be a big deal but I am sorry to all.