I am the new owner of a 1993 3rd Gen and the Car is not Idling well, when at operating temp. I was wondering if someone could please help me diagnose this problem so i can get out and enjoy this car. Thanks for the help a head of time

GameDog

 

You're going to have to be a little more descriptive....

Do you have a boost gauge to check vacuum at idle? Is the idle unsteady? Is the idle really rough -- shaking the car? What rpm is the car idling at? Does it drive smoothly once moving? Is it making good power?

 

Oh yea i forgot to mention that the car will sometimes not idle at all and just stall if i let it.

 

Thanks for getting back so quickly... No boost gauge at the moment..... When the car is warmed up it will idle at a very low rpm...( 300rpm or just stall) Power is okay, and i felt both turbo's work.....the car is still fairly new to me... i will have it out tomorrow and i can focus on your questions more to get the right answers.

GameDog

 

~Bump~

 

You try adjusting your idle screw? Have you done maintenance such as oil changes, plugs, etc? try adjusting TPS, if the first two dont change anything

 

ok, I took the car out today. when cold the car starts fine, and at warm temperature it idles amazingly well.(750 rpm). however after driving the car for about 20 mins ( normal/performance type driving) the car will not idle, and will not start again until it has cooled down. it seems to be getting extreemly hot, how ever the temp gauge reads just above the halfway point, and the temperature light does not come on. once the car has cooled of it starts and idles fine. it was 75 degrees today, it ran great for about 20 mins ,and then stalled and would not start until it cooled for about 15 mins. then it ran great until i pulled into my driveway , and it would not idle .
Thanks Again
GameDog

 

Fuel system solenoids

Download a factory service manual if you don't have one yet and check out your pressure regulator and purge control solenoids.

Is the ecu throwing any codes?

 

the stock temp guage isn't very good. However if the guage is over 1/2 this points to a potential overheat problem. The stock guage is very inaccurate. By the time the guage moves to the H, you probably have blown the motor. Therefore, I would recommend using an aftermarket temp guage.

If the rx7 is running hot (overheating) it will run shitty. I had this problem before when I changed coolant and didn't burp down. So I was running low on coolant. The idle was really low, the car would stall at idle, didnt' want to start (sound familiar?)

If you're trying to judge normal operating temps by the stock temp guage, it should be no more than 1/3 of the way up. My stock guage actually reads lower than 1/3 of the way up most of the time except in heavy traffic or freeway runs at high speeds.

If I were you, I would refrain from driving your car until you change both oil and coolant. You should do other maintenance if you jsut bought the car. This car requires a lot of attention in the way of parts replacement and fluid changes. Neglect it, and you may no longer have a running car.

When you change coolant, make sure you "burp" it and that it's full. A bad coolant cap can also cause the car to overheat.

 

You have a very oddly behaving stock gauge. Typical behavior is they jump up to ~1/2 way between C and H when coolant temps hit about 130-135. The needle will not move 1mm from that point until coolant temps are above 235F. At some point above 235F (I believe around 240-245F), the needle will start moving toward H fairly rapidly.

 

Strange, my car's temp guage has always been this way. Maybe im judging 1/3 of the way up to be 1/2 of the way up for other people. Mine goes up to 1/3, but moves up over 1/2 when my car is running hot (the only time it did that was when I was running it low on coolant).

I'm guessing that maybe its
1. my thermostat (stuck open) or faulty sender
2. The previous owner recalibrated it
3. my car and the guage are just "different"
4. my car is running cool due to the fact that I run fans constant and GTC front bumper (unlikely if you say the stock guage is supposed to go to 1/2 at 135F)

I've already ordered my PFC w/ commander, just waiting for it to come in. So hopefully, ill be able to get accurate temp readings soon.

 

rynberg my stock gauge on the 94 moved nicely along with my readings from the pfc commander...I guess it's not everyones stock gauge that sucks. on my 93 it didnt move at all though from the center even when I was at 210 a couple times.

 

The moral of the story is get a PFC!

 

thank for the help, ill cgange my fluids, and bleed down the coolant system and start there, hopefully ill have it fixed in the next couple days.

Thanks Again Guys!
GameDog

 

could be a coolant temp. sensor going out. might be sending a false signal to the ecu causing it to think the motor is cold and richen up the idle and die.

 

I am an expert by no means, but a richened idle will be very noticable. There will be smoke/ pop-pop-poping at idle, which he has not mentioned at all.

I think the car would have to be pretty rich for it to die. On my car, a disconnected map sensor will cause the car to run super rich and fluctuate the rpms, but I have not had it die out at idle.

A bad Intake air temperature sensor could also cause the idle to richen up, but I dont it would cause the motor to die.

I think this is a key point in his post. Again, I could be wrong. But it cant hurt to change fluids.

 

Sounds like the temp guage may have been linearized.

 

does anyone know where i can DL the owners manual

 

You can download the factory service manual as well as the owner's manual from www.iluvmyrx7.com

Go straight to the infamous Section F....

 

~ Tahnks but this comp sucks so it wont let my DL it and open it ~ guess i have to find one and buy it ~