94ZR1

When I turned on the power key yesterday the engine would stumble badly and miss at 3000 rpm when the 2nd set of injectors came on especially noticeable in 4th gear

It ran fine with the power key off
I just put a new serpentine tensioner on it but I dont see anything around that like a loose plug I knocked off that would cause that
Does anybody know what this could be?

YorkL8apex

Check out this post, same problem, lots of discussion on possible causes.

http://forums.corvetteforum.com/c4-z...er-key-on.html

MRDZR1

Gentlemen!

Here's how to avoid power key, injectors, miss at 3000rpm, etc... issues my friends!

#1) Power key "ON" all the time!
#2) Pedal under the right foot on the carpet as much as possible

This should help avoid switch and injectors miss behavior!

Martin

PS: Had a vacuum issue on my old mans '90 secondaries a few years ago! Some of the flex tubing run in front of the engine so...?

94ZR1

You nailed it
When I was putting the tensioner on it is very tight in there and I broke a hard plastic vacuum line that runs from under the front of the plenum to in front of the coolant tank under the pass headlight

BTW would someone please tell me who the douchrocket is who decided that hard plastic vacuum lines were a good idea

MRDZR1

Yep, pretty weak material for this purpose but cheap ($), lighter weight then aloy and easier to process for the OEM tier 1 supplier at that time.

As for the tip, my pleasure!

Goldcylon

Rumor has it that it was the same engineer that designed the C4 around the heater core

94ZR1

Also the same one who put the Lt1 and LT4 water pump above the opti