Is there a way to test if one or both anti-after burn valves are working properly?

Unfortunately, I only have a spare for the top one.

I've been chasing a cold run issue that no one seems to have any solution for. I'm throwing some spare parts that I know are good at it, but don't know how to test these.

It's an 85 12a with a RB header. Everything is stock except the header and no air pump.

Thanks

 

Hello I’ve been studying the GSL-SE fuel injection system to run it on a 4 port rx8 engine. I can probably help you with this problem. From my understanding is that this part it only comes into play when your going from using fuel to not. The anti afterburner valve Supplys air to the exhaust system to convert unburnt fuel in the converters. Maybe tell me or us if someone else helps what your symptoms are and if you have any modifications. Also can you tell us what you have tested so far? The more information the better as systems on cars can be caused by many different conditions and often is tricky to diagnosis when there is possible that a few different things can cause same problems. I posted bellow some photos that may get us started in the right direction.

 

Thanks, the only issue I have is that it will not idle in below 40 degrees F. Above that, it runs flawlessly.

While driving with throttle on, it runs great regardless of temp. But when you let of, it idles down to shut down. Even if I feather it down, it won't idle when it's cold outside.

So far, I've cleaned the jets, air bleeds and the general carb with just the top section off. The floats are mid level. Doesn't really seem like an internal carb problem. That's why I was looking at some of the external pieces that may be prone to the cold. That shouldn't even be a problem since once it's warmed the engine bay should be warm.

This thing used to love to cold weather, so not sure what changed.

 

Check your automatic choke. Sounds like in cold days it’s closing even with the engine warm. It’s in my opinion that it has nothing to do with the smog pump and valves. If not your automatic choke then let me know and I’ll try and think of something else. But given your description this will be the best place to start.

 

I'll check that and see, I know that once warmed up, the choke clicks off inside the car. I'll drive it for a bit and then take off the air cleaner lid to see if it releases.

One of the other things I did was check the function of thermo sensor that diverts incoming air from the exhaust manifold, now the header. That does work as intended.

Thanks for the insight on this. It's frustrating letting it sit for weeks on end. I don't know how people store their 7 all winter!

 

Well, after driving it around till warm, the same results, but I do see that once the choke clicks off, the carb is open as it should be.

I messed around with idle, fuel mixture and timing. Now that it's warm, it's running pretty well. I'll have to try again tomorrow after it's fully cooled down.

I put the idle back at about 1100 RPMs. I leave it here since my a/c no longer bumps up the idle. Another issue for another day.

When adjusting the idle, fuel mixture and timing, I put it at around 700. It idles fine there, but the a/c will kill the engine.

 

Today the problem is improved, the engine no longer stalls, although it comes very close.

The other problem I have created is a major lag at initial throttle. There's a noticeable stumble before the engine starts to rev.

Tomorrow, I actually have space in the heated shop, so I'm gonna take a deeper dive into the carb. If I can't make it better, I'll return all the adjustments and do a carb rebuild next winter. I just don't want a month or so down time just as winter is coming to an end.

 

YOU NEED YOUR AIR PUMP! U need the air pump for any of the decel air injection smog valves.

 

I think thats right, the air pump is needed for these to even function.

 

Thanks, I'm surprised it affects both, but it makes sense. At least something to cross off the list!

 

Now that I've taken the top of the carb back off, can I take the anti-after burn valves off and block the vacuum lines?

It would be nice to continue to de clutter the carb area, but I'm not going to fully strip it down. I'll eventually fix the A/C compensator and I need the cruise control.

 

I ended up reading through the carb stripping tutorial. This gave me the information I need.

As always, I appreciate all the input as I continue to learn more about my 7!

 

Next step, hog that bad boy out Chris! Unlock the ponies!

 

That's the next step. I sent an extra set of venturies to a friend of mine in Missouri. He's a retired machinist and he is going to do it for me. I have a lathe, but metal is not my thing.

 

My personal experience with hogging out the Niki is don't **** with the Venturiis.. I did it on a lathe at work but drivability suffered. Ran like ****. They looked just like the ones in the write up. But didn't work.

 

I did with a dremel and some valve grinding compound.

 

I'll see what happens, I have two more extra sets, so if it doesn't work I can do something different.

I just don't think I could make them perfectly uniform doing with a dremmel. I know they shouldn't be polished smooth, but I would think being consistent is important.