Ok, 1983 12a, stock motor, nothing modified except the exhaust leak.

I am at a car meet and of course everyone is pulling out at an accelerated rate. I was in 3rd at about 5500 when the car starts shuttering, like its not getting fuel or spark.

It couldn't be spark because I just replaced the cap and button. So it had to be fuel. But the car runs fine except when its doing hard acceleration. Any idea what the problem might be? And how to correct it?

 

Under a load a engine needs more spark and more fuel. Could be that you have a restricted fuel filter, a fuel pump that is not putting out enough volume. The float level may be off in the carb. rx7doctor

 

Also your secondaries may not be opening, or only opening slightly. This is my problem I found out after replacing fuel pump, dlidfis, and a few other misc things.

 

If its the secondaries, I guess this requires a carb rebuild?

 

dude i bet you 10 bucks if you put a new fuel filter in your problem will be solved

 

the reson i say this is because this is very common for higher rpm acceleration loss, and the secondarys TO MY KNOWLEDGE open up way before 5500 rpms..

 

New fump and filter made mine way better, but I had to rebuild the carb too. Good luck.

 

Like I said it only does this under high stress. I can rev it in neutral all the way to 8k.

Think walmart has the right fuel filter?

 

clogged catalytic converter

 

^ anyone else make this as a valid claim?

 

Most likely a clogged fuel filter. This is the #1 cause of this problem. I have the same problem right now. But I'm doing some investigation as to why the filter I put on only a week ago is clogged with rust again. All the fuel lines and the tank are new. All except 1 line. The one that goes from the tank to the filter.

 

replace filter
then check the pump if its still a prob

 

My secondaries do not open all the way. This results in a power loss in third gear roughly 4.5-5K WOT

 

Yes walmart will most likely have your fuelfilter.

Before i had my sterling carb, i got a really quick sputter under high stress/rpms. I replaced my fuel filter and pump(needed to for the slerling anyway) and that still didnt fix it. But now with the sterling carb, it runs strong all the way

 

Changed the filter, tried the same situation. Same amount of fuel, didnt have problem.

 

possibly cat, but i'm thinking fuel.

 

So what was the result on this thread - what was the final fix?

I have a similar problem on 83 rx with 205,000mi. High end power fade, but accelerates slow anyway. Here is a list of symptoms plus things I have already checked.....

problems 1st. slow to accel. maxes out ~65mph. This has been slowly creeping up over time. Was good to 90, then 85, then 75 etc. It is a daily driver so it came on slowly over a month or two. Plugs have been pretty white.

So, I put a new fuel filter in it (2 actually in the last 2 months), new plugs, new wires, new cap and rotor just for good measure because of mileage and i can't remember the last time that stuff was changed (less plugs). I checked the fuel flow and it comes out to spec ~1.5qt/min.

This weekend I looked at it some more. found that if you rev up slowly (in neutral), it will climb smoothly to ~5400. add just a little more gas and it sputters out. Alternatively, if you mash the pedal in neutral, it will rev to about 5000 and complain all the way. As it turns out, the secondaries are not opening.

What do I do to get the secondaries moving?

 

3 posts up from this one.

 

LOL, god i suck (everyone knows this already ) i should read the whole thread before posting.

 

OK - so fuel filter appears to fix that guys. How 'bout secondaries not functioning?