Hey every body. I have 1979 rx7, 5 speed manual, almost completely stock. I have put a K& N in and upgraded the ignition to an 1981 ignition. I have replaced all the vacuum lines and have tuned up yearly even though I use the car only a few times a year. In Dec. 06 I parked it due to a leaking fuel line. About a month ago I pulled her out of the garage, fixed the fuel line and took it down to my brake guy and had the lines flushed. I noticed it would hesitate and stutter when I would put my foot on it but if I gradually speed up there is no problem. It also seems inconsistent but cannot connect it to time of day/ temps etc. I also had him replace the fuel filter (and then performed a volume test for one minute- 1.1 liters back at the house-OK) It seemed to help temporarily but the problem came back. I then talked w/ the manager at Checker who told me they had run on fuel filters so I Installed another one and determined the brake guys put theirs in backwards. Thought the problem was solved-ran great but the problem came back again. Now I check the return fuel line check valve and it was extremely hrd to blow through- the manual says it should be easy. So I order a new one from Mazda-compare it to the old one-big differance-install it. Runs better but again at cruising speed when I go to step on it it gags and stutters. Now it is worse than ever-OK if I slowly accelerate but no zip. I do not have this problem before I parked it in Dec. What should I check now.

 

Might be time to clean the entire fuel system. Start with the screens in the carb under the banjo bolts on the feed/return lines. Move on from there to include dropping and draining the tank if need be.

 

Thanks- So check this out- Now I hardly drive the Car and 7-8 months ago I put new plugs in-BRQ14s-and have put on maybe 500-800 miles. After I posted this I decided for ***** and giggles to check the plugs. They looked pretty dirty so I wire brushed them and sprayed with some brake cleaner. Put em back in and its driving great--so far. How fast should the plugs build up carbon deposits-is it indicative of something else.