I have a 91 model tbi 350 in my 76 cj7 runs great except when I get down on it pretty hard it starts busting up.Any help

busting up? what does that mean?

does it backfire, stall, miss, act like it hits a wall and not accelerate further, I dont know what busting up means.

you could try plugging another computer from the same year motor in, try checking the advance weights under the disributor cap, check for a vacuum leak, increase the fuel pressure to the TBI unit as it may fine at idle but not so good for the higher demand at 4500+ rpm, it could be a number of things but need to be more specific about what busting up means.

I hope this helps a little. Try going to www.fullsizechevy.com and check out performance mods in the forums there. I found a lot of helpful performance mods for the TBI in there.

Good Luck,

JJ

Don't go above 4500rpm

Check your fuel pressure at the high rpm.

Depending on what the hell your cyrptic message means.

I would start by giving it a new tune up, Plugs, Wires, Cap, Rotor. Gap the plugs right. Get some 8.5 or 9 mm spark plug wires.

Get a good coil too. not a cheap chrome one because it looks cool.

I am betting on ignition not gas. On a tbi if you have 14lbs at the injectors constant on a stock motor it will handle it to redline.

Have you tried reading the error codes? That type of condition will usually store a code in the computer so you can pull it later.

according to my Tach. I have a 95 350 tbi. and the red line is 4500. so its your rev-limiter.

Depending on what the hell your cyrptic message means.

I would start by giving it a new tune up, Plugs, Wires, Cap, Rotor. Gap the plugs right. Get some 8.5 or 9 mm spark plug wires.

Get a good coil too. not a cheap chrome one because it looks cool.

I am betting on ignition not gas. On a tbi if you have 14lbs at the injectors constant on a stock motor it will handle it to redline.

X2

Those truck engines don't make any power above 4500 unless you have modded it. Busting up probably means your valves are floating.

Happens all the time if you leave in the knock sensor and ESC. False signal and you loose timing.

If it's not what they said about needing a tune up!