I have an '85 GSL with a 12A and MT. I have this wierd problem that virtually only occurs during autocrosses (which makes it VERY frustrating).



So today we had 3 runs. My first two were fine in terms of the problem, but on my 3rd run coming out of some of the turns (in second gear) it was very "bogged down". I step on the gas and nothing, until it recovers a second or 2 later and seems normal until the next turn.



The first time I experienced tis problem I had almost no gas in the tank, so I though it was simply the gas in the tank sliding to one side and the pick-up couldn't get it. Since then I've always had more than 3/4 of a tank for my runs and the problem continues. Today, I filled it all the way up just before my runs (again, my first 2 runs were alright).



After my runs, I opened up the gas cap and there was so much pressure that a small amount of gas rushed out. Whenever I fill up it does "whosh" when I open up the cap. Is it supposed to do that?



Also, on my way home, it seemed to do the same thing... but in a straight line. It was running a little hotter than usual due to 30 mins on the highway, but not overheating at all. From a stop in first gear, I revved it up to 7000 and almost exactly at 7000 it "bogged down" again, but i kept my foot on the throttle. It slowly went all the way down to about 4000 RPM and then suddenly jumped back into action. I did that twice consistently. https://www.nopistons.com/forums/pub...1047683561.gif



If anybody can help me out, I would greatly apprecicate it! Thanks in advance!

I was going to say that our carburetors (if not GSL-SE) tend to have a stumble in tight (left hand only I think) turns. But your problem at the light isn't consistant with just a design problem.



I would check:

Your fuel filter

Your tank's "Breather" lines.



Check the Heynes manual, there are supposed to be lines that let off the pressure and fumes from the tank. Those should solve your pressure problems, but I don't think they're related so much to the stumble. The fuel filter could be though.



The next place I'd look is at your carb. Are you running stock or aftermarket? If stock, when was the last time it was rebuilt, if ever? You could run a can of carb cleaner through it, that might help, but you'll probably want to get it rebuilt.



Hope that helps. Anyone on here correct me if I'm wrong https://www.nopistons.com/forums/pub...DIR#>/wink.png

Jon

Hey, sounds exactly like my problem.



When I first got my 84 GXL it ran pretty good, but it would stall all the time, so i took some carb cleaner and checked the carb. The carb desperatly needed to be repaced or rebuilt, and since I couldn't afford a new one I had a buddy of mine who has rebuilt RX7's carbs before, rebuild it for me for $300 https://www.nopistons.com/forums/pub...#>/biggrin.png I figured it would take me two weeks to do what it took him to do in one day.



But after the carb was rebuilt it felt even MORE sluggish! After I run it today I'm gonna check if the venturies are opening. If I'm not mistaken, I should get it hot, shut it off, push the gas to the floor and watch the venturies, correct?



As for the gas tank "wooshing" when you open up the cap, I think that's normal because there is a vaccuum created in the tank. I've had several other cars that it has happened on, and I'd assume that's why they tell you on the gas caps of newer vehicles to open the cap slowly.



I need to check my fuel filter too, but I'm really not up for checking it if it's not causing me a problem. *sigh* I hate having to go through every single piece of my car to find only one thing wrong.

I guess it only lets me edit my reply once....Anyway, this is what I was gonna add:



I've had people tell me it could be a number of problems:

Fuel filter

Vaccuum leak

Loss of compression

carb rebuild went wrong

The fuel filter costs $5, and literally takes 5min (including putting the car on stands) to change. Two clips, slide hoses off, put new filter in, slide hoses on, two clips. Done.



As for the sluggishness after the rebuild... You payed $300 for a carb rebuild?!? Rx7Carl on the other forum will do it for half that, and he'll even beadblast the outside, and wash the internals properly! Wholy crap! For an extra $40 you could have gotten a Paul Yaw Carb... man you got ripped off.. and if he doesn't do Rx7 carbs specifically, and all the time, then he doesn't know all the things that Carl, Sterling and Yaw know about tweaking them for best performance on our cars.



$300 dollars? Jeez, for a simple rebuild I hope he used gold-plated gaskets.



Jon

Thanks guys, I'll try some of those suggestions. Except it'll be difficult to tell if it works until the next auto-x... oh well. https://www.nopistons.com/forums/pub...O_DIR#>/11.gif

UPDATE:



I put in a new fuel filter and it didn't seem to help much. It seems to happen when the engine is hot (not overheated) as in I've been driving it across town all day or auto-crossing @ high RPMs.



Also, it seems to happen almost exslusively on RIGHT TURNS (with a few exceptions in straight lines at high RPMs).