i searched for like 2 hrs and i cant find this at all, my exhaust glows red hot, I have a 21/2 inch straight piping with no cats, and it still glows red hot. and my car idles at 3k rpm, until it warms up and then drops to 2700 any ideas on this situation would be great plz help

 

you might be runing way rich ?

 

i am, how do i fix it any ideas???

 

If he was running rich his temps would be cooler, higher temps is caused by a lean mixture. A high Idle is caused by a vacuum leak, which causes a lean mixture. Look for a vacuum leak and that might fix your problem. Also play around with the Idle screw, it might just be way too high.

 

In a rotary, glowing exhaust is almost always very rich or retarded timing.

Since timing just doesn't change, it's likely a fuel issue.

Start with a full tuneup. If that doesn't do it, test the coolant temp sensor and air intake temp sensor. If those check out, have your injectors professionally cleaned.

 

What? Glowing exhaust = Rich?

That statement goes against everything I have learned in life...

 

NICE!

On a serious note, I think I read somewhere (dont quote me on this) that its common for the header to glow red in first gens, dont know about our cars though.........whatever aaron said is probably correct though..........listen to him instead

 

If it is running really rich, the particals of unburned excess fuel end up burning up in the exhaust system as the particals make contact with the surfaces. Resulting in excess heat.

I have seen this from a cracked cast iron as well, with the coolant exiting out into the first cat (turbo car BTW) casing it to glow red. But if your cat-less I doubt that is your issue.

Sounds like you have a really big vacume leak due to the very high idle. Did you mess with your throttle cable at all? I would adjust that down to get the rpm down, and than re-calibrate your TPS after.

 

aaron you got some serious pull there bud

 

If the engine idles smoothly at that high of rpm, I would be less inclined to say it's a vacuum leak, and more likely a throttle being held open too much. Does the throttle lever actually touch the idle speed screw? if not, check to see if the thermowax unit, dashpot or throttle cable is holding it away from the screw (use a small mirror to see it). A large vacuum leak causes a high idle but is usually rough and shaky as well. If the thermowax unit is keeping the idle too high, check coolant level (trapped air) and thermostat (engine reaching normal operating temp).

 

i vote timing

 

Retarded timing can definitely cause it, on the other hand, he has a high idle, retarded timing usually results in a low idle, possibly even stalling. And, as Aaron Cake said, it usually doesn't get out of spec unless someone messes with it.

 

do you know of any easy was to search for a vac leak??

 

Read this writeup:

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/rx7-rough-idle-diagnosis-simplified-645051/

 

Don't forget to check the throttle and thermowax as in post #10 ^

 

I actually had this exact same thing happen to my vert when I got her...ended up being a bad TPS sensor and a shot ECU. One of the plunger thingies on the TPS was stuck completely open and would not move and my ECU was so water damaged from someone leaving the top down in the rain that everything on the board was corroded together.

Get a manual and start testing your sensors like the CAS and what ever else you can test. My pipes no longer glow red...

 

In the rotary, glowing exhaust is usually caused by a seriously rich mixture, or timing that is very retarded. The unburned fuel continues to combust as it's pushed out and into the exhaust. If you run the engine without an exhaust manifold (not recommended) you will see flames several feet long.

Generally this condition is just caused by a car that is out of tune. Check plugs, wires, etc. If it suddenly happened, it's going to be a fouled plug, bad wire, bad coil, or sticking injector.

Edit... a high idle combined with an only slightly rich mixture will create the same issue.

I've NEVER seen a glowing exhaust on a rotary car caused by a lean mixture. Never.

 

vaccum leaks lower your idle, why do you think that when you pull the one coming out of your intake your car stalls?