Is someting wrong with my Z?

[ffvetteman]

The past 2 times I have taken my ZR-1 out it seems to not have the same power it used to. It almost seems at high RPMs under full throttle, its not pulling. Kinda feels like it has got a small chug in the 5K -7k RPM range.
The car is a stock 92 , only mod is a Doug Rippie chip and it has 38K miles.

Im not sure if something is wrong or not, because sometimes it feels just fine, but other times it almost feels like it is chugging. As far as I know the plugs are stock and the wires are for sure stock.

I was going to start with changing the plugs and wanted to check what are the best stock plugs to get.

Also the check engine light came on . It would come on after running full throttle while I was slowing down.

Anyone got any ideas? I gotta run the codes to see why the light came on.

[1990 quasar blue]

I'd pull the code first. Do you have a GM shop manual?

[tf95ZR1]

I don't know if a code/light would come on (maybe if the engine is
starving for air), but a heated up (therefore occasional) intake
air duct may be collapsing. Check the archives for solutions like an
inside duct metal coil or sleeve, Coplon duct, Samco duct, etc.
Good luck,
Ted

PS Changing plugs is a good idea. I used ND Irridium - made a difference.

[ffvetteman]

I am going to pull the codes, but got home at 1am an just didnt get to it yet. The light only came on after running full throttle and after I let off the gas it came on while it was winding down from 7K with the cluthch in. I do have a Samco air duct on there, I forgot to mention that.

My next step it to pull the codes, its just not a rush, because I dont drive it much and I have a lot of projects to take care of.

I just wanted to check in and see what other ideas you guys had on possible causes. This car is much more advanced than Im used to.

[tccrab]

I'd start checking for vaccum leaks, sounds like your secondaries aren't opening.
Try a good hard 2nd gear pull with the valet key off and then a good hard pull with the key on.
It will be obvious.

Good luck!

TomC
'90ZR1 #792

[WB9MCW]

I agree with TC is the vacuum is down then no secondaries and the pull should be abt =.