I just bought an 89 Trans Am GTA that has some mild performance work done to it and I am realizing that it is cutting out at 4800 RPM's instead of the redline 5500.It acts like it has a rev limiter because once it hits 4800 it drops then comes right back up so I know its not a fuel starvation problem.I know that there is a stand alone fuel system and a Accel spark/fuel managment system but what would there be a reason for this? Any feedback would be great!

 

have you verified fuel pressure at that RPM?

When was the last time you did an ignition tune-up on it?

What type of induction is this? How big of motor? Is it a 5.0l, 5.7l, TBI, TPI, Q-Jet? Aftermarket induction?

 

It is a supercharged 355 with the stock ignition.The fuel is ok and I just gave it a full tune up.It feels like a rev limiter and I see that there are plastic type prom inserts that look like they could go into the Accel box but I am not sure and I do not want to start guessing.

 

[QUOTE]Originally posted by PaxtonChrgdGTA
[B]It is a supercharged 355 with the stock ignition.The fuel is ok and I just gave it a full tune up.It feels like a rev limiter and I see that there are plastic type prom inserts that look like they could go into the Accel box but I am not sure and I do not want to start guessing. It is a TPI car with heads,stock style intake with Edelbrock intake and SLP runners mated to a 1000 CFM throttle body.

 

Drops them comes back up....so it'll do this repeatedly, but not PASS 4800?

I'd say, your problem IS a rev limiter. Probably programmed in that Accel box. Of course "4800" on tach may not be "4800"...go by what the box says the limiter is, not by what the tach says it is.

 

it feels 4800 though because it isnt getting the full RPM band potential,it cuts out as soon as the car builds up on boost and starts pulling really hard.The onlt thing left I can think of is that maybe the N.O.S is triggered to operate at that RPM but the system was taken out of the car????????

 

Check the box for dial adjustments or for an rpm "pill" like the MSD box has. Then yell back what you find..

 

Could you explain what to look for,this is my first car like this.Thanks!

 

Look for dials on the side of the box, they'd probably say something like "rpms", the dial type usually have two dials, one for thousands and one for hundreds. If your limit is 4800, for example, the first dial would be at 4 and the second dial would be at 8.

A pill will be a little white connector-looking thing, pushed into the unit...usually has two prongs, and has an rpm number labeled on it, say "4800".

 

Hm,dont think I saw those.I have what are plastic come in a few widths ranging from 1 inch to maybe 2.5 inches,blue.They might not be anything at all but thats all I have seen.The car is going to the mechanic tommorow so I will find out more.Thanks for your help though it is well appreciated!