ypsiZ28

It is a 93 Z28 with a stock LT1. gets up to 105 then acts like it wants to stall i figured fuel shut off or topspeed limiter. how do i fix this? help is much appreciated

LucasZ

You have to get a performance chip. Check out http://www.pcmforless.com/index.php?...d=44&Itemid=40

n2ceptor

Did the vehicle come from the factory with Z rated tires???? IF not, then its limited..... My stock 93 was unlimited...

ypsiZ28

idk im one of many owners. the car is basically a *****. its had at least 3 including myself that i know of.

ypsiZ28

LucasZ, is that a reputable site?

moparman

What's the top speed number on the speedometer?

LucasZ

I have a 93 Z28 with the same speed limiter. You get to 105ish and ignition dies for a blip. On 93, you can't just hook up a reprogrammer. You have to replace it with a new chip. Last I looked into this 2-3 years ago, PCM4LESS was the vendor preferred on these discussion boards.

From: http://www.f-body.org/tech/4th_gen.htm

"The base tires were the Eagle GA with an S speed-rating. Any cars with these tires included a 105 mph speed limiter. The base coupes only came with the GA, but the V8 cars could be ordered with the Eagle GS-C (QLC) Z-rated high performance tire, which did away with the speed limiter entirely."

Injuneer

Look at your door sticker for the original tire size. 245/50-16 was the Z-rated tires. Or look at the build code tag for RPO "QLC", also for the Z-rated tires.

sactoz28

pcm4less does great work if you choose to go that route

ypsiZ28

Well my car is a frankenstein. the doors are from a 95 the nose cone and passenger fenders are from a 97 and the rest is a 93 so yeah. but thats ive got eagle gs's on it right now so i will definetly invest in the pcm route. thanks much. and moparman it goes to 115 or 120 i cant recall.

ypsiZ28

ive also noticed that these tires kinda blow. any suggestions for better ones in a decent price range?

Injuneer

Check the tire reviews "stickied" at the top of the "Wheels and Tires" forum.

moparman

If the speedo only goes to 115, the the original owner did not option it with the Z rated tires, so the pcm is programmed to speed limit it.

canuck94z28

Since yours is a 93 another way to tell is chk.your shift indicator.You shouldn,t have a 1 position& your factory gear ratio was 2.73.

bombebomb

I thought they was set at like 160 or something limited for the "unlimited" one's, maybe not