My 79 12a ported rx hesitates around corners. this usually happens when going faster than the posted speeds. Unfortunately everything else is stock at the moment. I.ve rebuilt the carb and adjusted the float level twice now. The float bowl fills up to just above half. Does anyone out there have any suggestions on resolving this problem? The distributer is electronic, carb and exhaust are stock. Any help? Thanks.

 

Maybe at higher speeds the exhaust back pressure is bogging down engine. You may need something more free flowing.

 

I had this problem at one point as well, except mine was a little more extreme. My car would actually die about 1/8 of a mile up the road. This really sucked in autocross, since it was extremely easy to do on the tires I use for autocross compare to the hard as a rock POS michelins that are on it for the street. A carb swap has seemed to have solved the problem. Apparently these Nikkis are prone to this. I'm not a carb expert, but it was explained to me that the fuel was moving around too much and ended up flooding the engine. But the new Nikki I put on was purchased from a guy who runs IT7 cars and I know it has been modified. Unfortunately, how I don't know. Supposedly an aftermarket carb is a good way to solve this, but that can be a lot of money/problems with emissions.

Hope this is possibly of some value to you. I'm going to go back to pretending to work.

 

Does it only do this when you're low on fuel? I've noticed that when I have only 1/4 of a tank or less the fuel sloshes away from the pick up when cornering hard and the engine starves of fuel. Mostly on long sweeping left hand turns.

 

No it does it when its full too. Seems to be just a bit of a stutter as you accelerate around a corner. Waiting another year for exhaust and carb work minus emisions crap. Won't need to get tested after 25 years. Can't wait. Thanks for the help.

 

Yup, sounds like what mine did.

 

Several possibilities come to mind. First, make sure you are setting the float levels properly 15 mm inverted and 51 mm upright with the gasket on. Second, you might try smaller jets on the primary. If someone else has rebuilt the carb, there may be something larger than the stock 83 jets. Third, check the fuel filter, you may not be getting full flow, and if the fuel pump is original, it may be getting tired. On our IT7 cars, we generally run a 95 jet on the primarys with a fuel pressure of 3 psi, any bigger and the engine tends to break up on slow acceleration. Bottom line: sounds like there is not a proper fuel level in the bowl, and the carb sucks air on the turn. (oh yea, check those silly little filters on the fuel line bolts!).