Well when i first got my 87 RX-7 N/A the guy that I bought it from told me that when the engine warms up it sometimes start running rough. But I still bought it ($800 yes it was a bet), what it did when it warmed up was like if it wanted to turn off and when put in gear and wanted to take off it would take off really slow because even with the gas pedal all the way down it would still not go like normal but really slow I would just let it sit for acouple seconds and the engine will go back to normal. I did the tune up spark plugs, cables, oil, oil filter, and air filter and I also bought a fuel injector cleaner and it did not do that anymore the car was now perfect. But just yesterday about a month of driving the car daily with no problems it started doing that again but only when it warms up and sometime if turns off or if I turn it off it has a hard time starting until it cools down for about five minutes and then it is good to go again. I checked the oil and it is full, I was wondering if it is because my straight pipe exhaust is ripped by the cat converter or if i need to change the fuel filter. Well I really have no idea why it does this someone please help me why does it do this?

 

it sounds like the dreaded 3000 RPM hesitation. Check th eFAQs her eI think I posted something about that. If not I will get you more information.

 

Fuel filter would be an excellent place to start. When you disconnect the inlet line at the bottom of the filter, allow the fuel to drain into a clear container as well so you can check to see if there is any water in the fuel. Water will settle to the bottom of the container and should be fairly easy to spot.

 

It just started to do this yesterday when it turns off and if I then try to turn it back on plenty of smokes comes out of the muffler it smells sort of like gas and it burns your eyes just like when a car doesnt have a exhaust...

 

you could be running too rich. Does your car ever flood for no reason? Your injectors may be leaking or injecting too much fuel. Check the injectors, make sure they work and clean them out while yo uhave them. Also check the fuel filter which would be easy to replace. It's most likely a fuel system problem and possibly ignition.

 

No my car really hasnt flooded in the 2 months that i been having it so you believe its something with injectors and fuel filter what about fuel pump...?

 

It could be the fuel pump but thpse rarely fail. More likely the injectors. Check the ENG INJ fuse and make sure it's getting a positive non-corroded contact, it's what powers your fuel pump.

 

well here are the updates, I have also noticed that when it starts to do all this it like shakes and then white smoke comes out of the middle of the car by were the cat converter is and at the end of the exhaust pipe the smoke comes out brownish. Today we changed the fuel filter and it stil had the same problem checked the fuel pump and it still did it im gettin a pretty good sparg and their seems to be no water or gas in the spark plug could the problem be the cat converter of too much unburnt gas collecting their because when the car starts to do this it smells like unburnt gas.. or could it be some kind of sensor.....Some one please Help Me Out...