When I got the car I noticed the part which looks like a nozzle (circled in green) was not blocked with a plug. Then I bought a spare engine and I noticed on the spare engine that nozzle is blocked so I transferred the plug to my current engine. The problem is after I did that I noticed in stop and go traffic the idles drop down to an almost stalling point. There are no problems with cold start up but as soon as I go in traffic it's a problem. It's also a problem if I try to reverse the car put in first gear, reverse again etc. The revs fall down to almost 500rpm then climb back up to 600rpm and I'd say normal idle is around 750-800rpm.

Anyway, yesterday I removed the plug again and revs are all normal again. The car idles around 900rpm and in stop and go situation the revs drop to 1000rpm and then slowly drop down to 900rpm so no more stalling feeling. But I think this is only a bandaid solution. Anyone knows what causes this problem and how I can fix it?

The second thing is when I look at the RX7 diagram ( http://www.rx7.org/Robinette/images/hoses.gif ) the hose circled in red goes to the blow off valve, but in my car it is blocked off. I'm pretty sure I can hear the bov working (cause it doesn't sound like the turbo stutter sound). So I dont know if this is ok not.

 

so you created a vacuum leak in order to raise your car's idle?

 

Well yeah, that's how it was before, and I fixed the vacuum leak then pulled the plug off again so it's driveable because I don't know how to get to the bottom of the problem or where to start. My mate told me not to mess with the idle cause apparently it's very sensitive and at first look I couldn't find the idle screw anyway.

 

Probably should look to see if your BOV is hooked up..if it isnt, route it so that a line goes to your BOV...or block it off and raise your idle...the idle is not "very sensitive"...just like any other car...just turn it up till your at w/e idle rpm's you want..

 

To adjust idle: https://www.rx7club.com/showthread.p...ht=idle+adjust start with post #8 for info on idle adjust straight from the FSM.

It sounds like there might have been a fellow messing with vac lines on your car that did not know exactly what they were doing and did not have access to a FSM. I would use the diagram that you linked a pic to and start tracing vac lines to make sure they are all plumbed correctly.

You need to make sure the BOV has a pressure/vac source to function properly.

Is your idle erratic like you have a vac leak with the other (green) plug off? Does the idle stay stable? If it does then it may not be a problem. I cannot see any green or red circled areas on anything you have posted so it is difficult to tell exactly what you are talking about. If the idle is not stable you have a vac leak that needs to be corrected, then the idle adjusted. The idle is VERY easy to adjust by adjusting the air bleed screw under the throttle body though it is difficult to see and you have to find it blindly with a flat screwdriver.

 

arkman, the green area circled is the vacuum nipple on the UIM closest to the fire wall in between the two center bolts holding the UIM to the LIM, the red is the other vacuum nipple.

OP: It appears that someone was messing with your vacuum hoses, there is supposed to be a hose going from the "green" nipple to the BOV and somewhere else, but I don't remember, stock the red one is blocked off IIRC. The vacuum hose attached to the "red" nipple appears to be routed somewhere, I'll have to take a look at my car to see just exactly where as I don't remember a vacuum nipple there. For arkman the extra nipple I'm talking about is right below the main stud bolt on the UIM.

 

Thanks guys, I'll look into it. I'll first try blocking the nozzle again and adjusting the idle, although nobody seems to be clear on which of the screws is for warm idle. If I didn't read it wrong, it may be the one closes to the firewall or under the throttle body.

 

My apologies. For some reason I was not able to see that pic before. Above is correct. Red goes to bov and from factory the green is blocked off. Most use green as a boost gauge pressure source. If you do not have a boost gauge I highly suggest you purchase one. The upper port the red line is attached to is odd.. I do not have that port on my uim.

When adjusting the idle don't mess with anything other than the air bleed screw and see if that corrects the idle first. Warm the car up then adjust air bleed screw (under the TB).