Hi guys, I'm new to the forum so whats up? Anyways heres my problems, I recently bought a 87 N/A 5spd for dirt cheap from a lady car has 60k miles on it and was a one owner car she took VERY good care of this car (windows were'nt even tinted) So anyways she said it ran last november but had a dead battery. so 400 bux later i owned a low mileage rx7. now is where it gets fun. i got the car to start, after a new fuel pump, plugs, wires, fresh gas, fuel injection cleaner, new battery, and an oil change. when you first start the car it will run pretty good until about 3500 rpms then with steady throttle the car starts sputtering (like cutting in and out) you can turn the car off and re start it and it will run fine all the way to 7k rpm for 1st gear then starts cutting out about 4500 in second,

If the car is just started it will take only about 1/4 throttle at 3500 rpm and starts sputtering and will not rev past 5k very easy (unless you restart it once) and if your just crusing at lets say 45 and back off the throttle, like not all the way off, but just enough to stop accelerating it starts jerking and spluttering. also it does NOT THROW A CHECK ENGINE LIGHT!!!. when it first starts it idle's VERY erratic (like from 800 rpm to 1500 back to 800 up and down up and down pretty fast) one of my buddy's told me it was the catalyst converters stopped up, and you can smell them (rotten eggs smell) and there is NOT ANY SMOG LAWS IN MY COUNTY so if it would fix it i could chop them sob's off. help guys and thanks.

 

Do a compression test first.

You might as well get rid of the cat, if you don't need it. It could be clogged up and giving you problems.

Check the secondary injectors and the TPS.

 

replace the fuel filter? it might be clogged!, then look for vac leaks, tps , and injectors.

 

Grounds! Your secondaries could be stuck too. You're getting the 3800RPM hesitation problem. VERY common with FC's.

 

ok I have replaced the fuel filter. and checked all vacum hoses. still the same problem. so check all the grounds for the electrical system, replace tps, and where/what are the seconderies??