Hey All

Still having boost issues, so I'm trying to educate myself thoroughly on the car. I need educating, and tonights lesson I'd like to be on the UIM.

My car is a stocker.

There are two random air hoses that don't seem to appear in the common vacuum diagrams I've collected so far. One comes off the intake elbow and dissapears in under the UIM, the other (or is it the same? doubt it!) comes out from under the UIM and vents to the air box. I know someone out there can tell me what they are!! (so please do if that is you ) I am yet to venture under the UIM. That is high on my list of to do's though if I can't solve my boost issue otherwise.

Your reward for assistance tonight, some pics of my car.

www.members.iinet.net.au/~jef/rx7

Thanks heaps guys, appreciate the help

 

the one that comes off the elbow and goes under the intake manifold is the AWS hose. Its the warm up system, thats revs the car a 3k when u start it. This is supposed to warm up the precat. The other hose going into the airbox i am unsure of (as to what it does exactly).

Boost issues? Have you checked to see if the map sensor is plugged in properly? All the vac hoses secured?

 

Hmmm

OK so the one from the intake elbow heading under the UIM is for the AWS system (which hasn't been disabled on my car, still happens but I put it into gear to stop it.)

I'm guessing it works by bypassing the main throttle valve/s, and there must be a secondary valve (or aws valve?) that controls air flow through this hose. On cold starts this aws valve is open allowing additional air into the engine causing higher revs. Am I close?

And I don't know about the other one but I read something about exhaust gas recirculation, could it be for that? And if so, why would you want to recirculate exhaust to the intake box?

 

most, if not all modern cars recirculate some exhaust gas back into the intake for emissions and fuel economy purposes.

 

Sorry missed this bit before. The map sensor is plugged in properly, but I haven't had a good chance to get in and check all the vac lines. My girlfriend is crackin the ***** at me for spending too much time on the car (haha wonder how many people have this problem?)

I do know the 1" hose from y-pipe to CRV is baked at the y-pipe and loose. Need to get in and replace that. Also still need to check for the pills.

So was I close with how the AWS works?

 

Yep. There is an AWS solenoid under the upper intake manifold that's attached to the manifold itself. When the engine is bone-cold, it opens and allows air around the throttle plates via that rubber hose to the TB elbow. The extra air gives you the 3000 RPM cold start idle. If you blip the gas or put the car in gear, the AWS solenoid shuts.

There are a number of hoses going to the stock airbox. On the left, there are the 2 relief valves - one is basically the stock blow-off valve, and the other is the charge relief for the second turbo's pre-spool. Going right from there are the 2 large intake ducts for each turbo. On the right side are 2 1" or so ID hoses - one goes to the air pump to provide filtered air for the air pump. The other goes back by the intake manifold, and eventually snakes around to the air control valve. The ACV controls where the air from the air pump goes - if the ACV has extra air that it doesn't need, it vents it back to the airbox. On the right side of the airbox is a hose that goes straight down and is connected to nothing - that's the vent for the ACV air. The airbox just has a muffler in it for the ACV air, then it's vented out.

Anyhow, that's more than you probably needed, but I enjoy newb questions that are well thought out and asked .

Dale

 

U can never reply with too much info mate, cheers for the lesson

 

True! Here's some more.

The hoses you're referring too aren't that. The EGR (exhaust gas recirculation) valve is attached to the lower intake manifold and the hose for that is small.

The EGR is mainly for preventing NOx production, but it is unnecessary and was removed from the '95 RX-7.