Hello, I recently picked up an 84 rx7 with a fuel injected 13b and I am new to the rx7 world. When I got the car, it had sat for a year and was not running because the fuel pump was not comming on. Anyways, I got that problem solved and the car runs. I can rev the engine in neutral and it will rev out all the way, but when I am driving, the car wil get a little over 3000 RPM and then stop accelerating and begin to buck and studder. Any ideas on what is going on? Thanks, Ryan

 

Sounds like fuel starvation.

 

OK... thats what I was thinking. I need to drain the tank and replace the fuel filter for sure, god only knows what got built up in there when it sat for a year. Any other suggestions that might help? Thanks!

 

The fuel filter would be the first the first thing to do and then go from there.

 

+1 on the fuel filter, I had the same problem a couple of months ago

 

If you're having still having trouble after changing the fuel filter, I would suspect the converters. They also can cause the symptom that you described. When they start to clog up, (if they're original than that's entirely possible), they'll let the engine freely rev all the way under no load. But when the car's in gear they'll choke off the engine as back pressure rises at 3k rpm and higher.
Let us know how you make out with the filter.

 

I will send beer if its not a fuel filter.

 

awesome, Ill let you know how it goes. SCCAIT7, if its not the filter, the beer will get here just in time for my 21st birthday! lol

 

ok... so I replaced the fuel filter and it still runs terrible.... each time I drive it, it seems to get worse and worse..... while driving it now I can get it to go above 2000 rpm. looks like ill be pulling the cats tomorrow

and just revving it in neutral it wont go above 5k....

 

what converter are you talking about?
i have a rb exhaust system and it seems like its doing that and i have no cats.

 

the stock cats....

 

ok thanks.

 

pulled the cats today and it still runs like sh**. And damn these things are loud with just an open header!

 

For those who know, does the 13b have a shutter valve, if so it could be the issue? How old is the fuel? Are the plugs and leads giving a good spark?

 

I dont know much about the rotary so can you elaborate on the shutter valve and how I could fix/ check a possible problem there. The fuel is brand new, When I did the filter, I drained the tank and put some 93 in. The plugs are new, but I dont know how well the spark is being transmitted to them, Ill have to check that.

Its weird because I first got it running for the first time in a year and I let it idle for like 15 min and at first it ran great, I had it revving out to 6k and then after driving it for a little while it had gotten progressively worse

 

I may be mistaken, but I don't think that the intake manifold for FI has a shutter valve. (I'll check my manual at the office). The shutter valve was made to shut of the fuel mixture from the carb to the rear rotor during deceleration (sp?) for emissions purposes. I would think that the microprocessor for the injection system would do this via the injector. Hopefully someone more familiar with FI pipes in here. I'm an old school carb guy.
Check for spark and let us know.

 

I think it could be a number of things including bad fuel pump/ lines could be gummed up/ bad injector /etc. I would check fuel pressure, I would also check the timeing just incase. Did you do a compression test on the car when you bought it?

 

alright thanks, Ill have to check the fuel pressure for sure because Im thinkin the pump might be going out, or any of the other things said make sense too. Is there a fuelpressure check valve anywhere on the fuel line/rail? or do you have to install a gauge in-line? Ill get to that this weekend and let you know how it goes. Thanks, Ryan