My 1991 dual ignition sputters when it's warm. It hasn't been properly warming up but I know why. But when it sits while running and runs warmer it will sputter in 2nd and 3rd gear. And in all other gears at high rpms. It's a manual. I feel like it's smog or something screwing it up but anything you guys might know?

 

When was the last time it had a tune up? I would start there. Fuel filter included

 

When my F150 starts acting up like that I run a tank of Regane and it clears right up.
Maybe its something as easy for your engine.

 

I went through and replaced plugs and plug wires. I have a fuel filter just need to put it on. I'll get some of the stuff and run it through. It just does it when it's warm which I find is weird.

 

My guess would be not getting enough spark/timing is off or not enough fuel...of course I'm just guessing through the interweb.
How many miles are on it? Have you done a compression test lately/ever?

 

The odometer says 38k but it doesn't have a hundred thousands place so it's safe to assume 138k. I haven't done a compression test ever. I went to autozone. I asked the guy there. He said clean the MAF and I got some of that fuel system cleaner and I also got some stuff that is supposed to seal the cylinders to fix any slight compression leaks. I also picked up some paint thinner to get the God awful camo paint the last guy put on the car. I'm 18 an I've owned 4 cars since I was 16. My first car was nearly exactly the same as this car just a 1990 and there is soooo much different. I mean I didn't have a MAF on that mustang.

 

I cleaned the MAF. It has helped. Hasn't cured it. It happens less frequently and less violently. So I'll go and clean all the other air sensors.

 

Hey, just a note on the paint thinner. Try using oven cleaner too. I use Easy Off oven cleaner. You can get it from Wal-Mart. As for the motor... Sounds like it could be an injector or fuel related problem.