Hey everyone,
I got one major problem on my hands. My 85' RX-7 has just been finally running since a long time of sitting in my garage. My uncle rebuilt the carb and everything so it at least runs. However, I was driving it today and yesterday, and I'll hit cruising speed, around 40-50mph in 3rd or 4th and my car will start jerking out of control. It will get to the point that no matter how hard I floor it, it won't go and it loses speed. Can anyone help me!

 

Clogged fuel filter? Maybe some sort of fuel delivery issue? A tired old fuel pump?

 

Fuel filter.

 

thats happened to me its the fuel filter and it'll soon get to the pump if you dont act fast might want to empty your gas tank out to get rid of what ever it was that clogged it in the first place..just saying from personal experience

 

Kool Kool, so according to everyone the final verdict is the fuel filter and or fuel pump.. I'll take a look at that this weekend. See, thats funny because I did replace the fuel filter and pump maybe a 5 months ago because the OEM one was gunked and clogged from the gas that sat in the tank for almost 10 years. But maybe I should change it again according to you guys, and I don't think it would be a bad thing. While I'm at it, I'm going to change fuel line hoses, put in a pressure gauge, and go the extra mile to eliminate this problem, Thanks Everyone!

 

Might also want to drop that tank and have it cleaned and sealed (check out radiator shops in your area)....I mean, really, if your going to replace all that other stuff again....crap in your tank is just going to cause the same problem again.....if that was the problem to begin with.
Change the filter...see if that fixes it....then decide what other stuff needs to be done.

Ohhh-Rahhh!

 

^^^agree my profile pic <<<< is a picture of my old fuel filter when i had sand in my gas tank

 

Hey Everyone, I just replaced my fuel filter yesterday and I haven't seen any real change. It still jerks and stalls out, I may go with patmac suggestion and drop the tank and get it cleaned, however that would take some time and all to get the job done. Does anybody have any other ideas before I continue evaluating and fixing this problem? my uncle who is a mechanic said there could be water in the system, but if that is true how would I get it out and are the effects the same as I'm experiencing. Thanks for the help all!

 

If it is wet fuel (more and more common problem now that we have ethanol mixes in winter) you need to drain the tank. The lines and carb will purge themselves within a short run time, but water in the tank will require you to drain it entirely & get rid of the contaminated fuel.

Could also be a carb that is getting dirty.

 

Alright Alright then, I know its not that... Had the carb cleaned and rebuilt about a couple months ago and the tank has been drained the first time I received the car, so I guess i could cancel that option out

 

You could have so much junk in your tank that its stuffing up the intake as
the gas is pumped causing momentary blockages. I think you need to drop the
tank. You already rebuilt the carb, changed filters and pump.

If it is wet fuel you can add stuff to deal with the water without dropping the tank.
I would try that first.

 

It only take about 30 minutes to drop the tank on an 85. I know, I did it on my lunch break one day, lol! Seriously though, I would drop that tank and clean it, I had the same exact problem. I would put a fuel filter on the rubber line going to the carb just in case there is any crap in the metal fuel lines also. I replaced the tank, filter, pump, rubber lines and rebuilt the carb as well as added that extra filter before the carb on mine. Sounds like you are in the same boat as I was.

Edit: Forgot to add that draining the tank does NOT get all the crap out of it after the car sat for that long. You should look at my old tank even after rinsing it out and shaking the crap out of it with a large chain in there. Still looks like crap and has stuff flaking off inside. Thants why I just replaced mine, I found one cheap. If there was a place local to me, I would have just had it cleaned and sealed and been done with it though.
Good luck with everything!!

 

Try cleaning your spark plugs and run your engine at night to see if theres a spark coming off the wires anywheres .....sometimes it can happen....but usually not the problem if your accelerating with no misses

 

Could be one of the venturis allowing globs of fuel out, causing the jerking. The fix could be as easy as cleaning the tiny holes in an air bleed lower tube. Can't recall what the tube below the air bleed is called.