I have a 91 Camaro TBI. When i'm on the freeway doing 90, i'm almost at orange line, is this normal for a TBI?. I use to have a 85 Z28 with TPI and at that speed it would barely be waking up. The car is mostly stock except for flow masters. Could it be that i have to adjust the transmission cable? my car has 195,000 miles with no oil leaks and runs great off the line so i don't think it;s the engine but i could be wrong. any suggestions greatly appreciated. thanks

 

Make sure you're in OD...count the shifts as you build speed.

Either you're stuck in Drive, or the tach is fubar.

BTW, what's the RPMs at say, 60mph?

 

Another thing, that would be pretty high RPMs for a TBI'ed Fbody...even in drive, unless the rear gears were changed at some point.

You sure the PO didn't stick a TH350 and 3.73's in there?

 

I know i'm not in drive. I bought this car recently and it has always been this way and i just thought it was because it was a tbi. going 60 i'm like at 3000 RPM

 

I have a 92 with TBI also. I don't remember exactly at what rpm it would cruise at 60, cause it isn't auto any more, but it was definitely MUCH lower than 3000 rpm. I went to the equations section right here on this site, and did some math.
Check this out...

Assuming a 13 inch tire radius and 2.73 gears (I think thats what you have stock), at 3000 rpm in 3rd you are at 85 mph.

Ok, now trying a 3.73 gear ratio (again assuming 13 inch tire radius), at 3000 rpm in 3rd you are at 62 mph.

Looks to me like the previous owner put in 3.73 gears.

 

With my 3.08 gears, and a 1:1 ratio tranny gear (third gear for you auto guys, and fourth gear for us 5 speed guys), and stock tires, I run just over 70 MPH (like 71 or so) at 3000RPM.
I know this for sure because I've lost my overdrive due to poor transmission planning by GM, and I have to run on the highway in 4th.

 

Thanks for the reply, is there any sure fire way of checking to see if i have the 3.73 besides taking out the gears? And if not is it for sure that this is the problem and it's not the transmission or transmission line or cat?

 

u can put the rear of the car on stands, and put it in netrual and turn the tires while watching the driveshaft to get the ratio..