I performed RNR on 85 GS and now i have no idle? Ive double and triple check my vac lines and plugs, and every thing seems to be in order. if I pump the gas ten or fifteen times it will start and stay running over 3000 rpm, anything less and it just bogs down and dies. Is it possible that the intake gasket could have been bad, and now with no rats nest it has compounded that problem

 

no. if the intake gasket was bad b4 it wouldnt have been made worse by removing the rats nest. check that everything is sealed properly.

 

ill check again, have a felleing the probleme is the large tube from the back of the intake i didnt get a block off plate for it i just bent it twice and hammered the crap out of it. im going to take it off and mig it shut in the morniing.

 

I bet that'll help. Make sure you cap the big hole on the back bottom of the intake manifold. It's near some oil lines. Very hard to see. But a very large port into the intake manifold.

 

ill look for that. thanks.

 

why do people remove the rats nest? Is it for more power or to simplify the engine operation?

 

One word---Leaks. Most of the vaccum lines, soliniods and hoses are so far gone that it is usually easier to remove that stuff, that repair it.

 

I removed mine and aside from the small idle problem that i likely caused ive noticed that the engine is much more eager to rev, but i also went to mec secondaries and did the AP mod all at once. from what i have read once the RNR is done you have a much better chance of finding a vacuum problem latter, or you have just rid yourself of several future problems, not to mention the way the Wankel looks when you can finaly see it.

 

That's about right. Also, what the other guy said - the old vacuum lines deteriorate. We could rebuild the rat's nest but most people remove the Air Pump and cats anyway so the rat's nest is generally not necessary.

 

That port at the back of the intake is the anti-afterburn hose connection and is a major cause of a vaccum leak. You would be better off taking a rubber cap that is used for blocking off coolant that the sell at the parts stores and putting a clamp around it. If you weld it then have to put the stuff back on for smog then you will have to replace the manifold.

And the answer to the question about performance gain, there is none, ZERO for the rats nest removall. The secondary mod will give you a crisper throttle.
And I don't know what all the panic is about vacuum leaks on the rats nest. If you don't lean on them and crack them you won't have problems. In all the rx7's that I have bought and sold and worked on over the past 20 years I have not had a car with a broken vacuum hose. I have had broken solenoid connections from people that have tried to just rip the vacuum hose off the solenoids though.
And it does not simplify anything as far as operation goes. As long as the equipment is on there everything works just fine. The only real inherent problems in that area are the shutter valve and air control valves which there are an abundance of them available used out there.

 

thanks doc, your right i would be better off plugging it, ill pick up a cap today. I have to go to town anyway, cause now the starter is out, good thing i bought the life time from Oreilys...

 

Anytime you go to an aftermarket carb , you pretty much end up having to remove it as there are no longer enough vacuum connectors on the aftemarket manifolds and some functions stop working because the new carb doesn't have the support for all the solenoids. I know that was the case for me back around 90 when I installed my RB Dellorto and RE header. Didn't need most of it any longer, so off it went. I just wish I had kept all the old parts I took off so i could be selling them on Ebay now

 

When you go to an aftermarket carb, you have to go with a header system also.
So therfore you are automatically removing the old intake that has the emission items on it. Then there is no need for the rats nests or solenoids and there is also no possibility of leaving things off or routing vacuum lines incorrectly.

 

alternativly, you could cut a peice of gasket paper to fit the flange on the tube and reinstall it without putting a hole in the gasket. if youve already bent the **** out of it, its unlikely that a vacume cap will seal it properly and the new gasket will save you the trouble of welding it.

-jason

 

Jason, the opening you are refeering to is for the port that allows air to go to the catalytic converter. That is not the port he is refeering to. The one we are talking about is below that closer to the engine. It is an integral part of the intake manifold and if left open the vehicle will not idle because it is a direct source from the intake manfold.