97 GTX can't get over 4k rpm w/o viloent sputtering and cutting out

[JeremyD615]

When you go back through the carbs, pay attention to the fuel pump diaphragm as well. It’s not common at all, but I recently had one that didn’t seal well around the edges, and it caused a high rpm shutdown that took forever to figure out... It would hold enough pressure to run at low to mid throttle, but once the pressure rose at high RPM it couldn’t keep up.

 

[rawdog2386]

When you go back through the carbs, pay attention to the fuel pump diaphragm as well. It’s not common at all, but I recently had one that didn’t seal well around the edges, and it caused a high rpm shutdown that took forever to figure out... It would hold enough pressure to run at low to mid throttle, but once the pressure rose at high RPM it couldn’t keep up.

What exactly should I look for?

 

[JeremyD615]

You’re looking for a needle that’s not closing fully or an aftermarket diaphragm that won’t let it seat all the way. It could possibly be gunk or trash that has found its way in there as well. At least that would be my guess. The carbs are really finicky on these things, and need to be cleaned/rebuilt every few years at least, especially with the lower quality fuels we are seeing these days.

 

[mikidymac]

Please read this.... Carb Rebuild Thread