Texas_Ace

iTrader: (18)

Ok, so after a month of work i have finally got my RX7 running pretty nice. A few minor bugs left to work out but more or less it is running and ready to get inspected. EXCEPT:

The idle, ever since i got the car my idle has been high. it used to be at around ~1500rpm. It is now even worse, ~2100rpm idle since getting it running again.

I had to take the intake off to fix the AUX ports and a leaking PD so i checked all the gaskects and used RTV when putting it back together. So i know all the intake is sealed. Plus carb cleaner doesn't show any leaks on it, nor can i hear any.

The injectors were just cleaned and have brand new o-rings/seals on them.

The TB does close all the way, i took it off to make sure and it is working perfect.

Vacume lines are right.

I have tried everything to get the idle down but just can't get it to come down.

No vacume leaks that i can either hear or that carb cleaner can find. I have sprayed EVERYTHING down with it. nothing.

And as far as i can tell the vacume hoses are all on right. i have 1 by one pulled them off and blocked the nipple off to see if it changed anything. The only one that had any effect on the idle when blocked off was the oil injector spider line. and i know it is in the right place.

So i am lost, what could be casuing such a high idle? ANYTHING would be great right now.

cr7684

iTrader: (42)

You can look at two thiings your Air Flow Metter & the idle screw on the TB.
Look into your AFM and make sure the is not staying open I hope this helps you!

cr7684

iTrader: (42)

Also on the top of your intake you have a screw I think it's call a idle speed? or something like that sorry it's been years.....

Texas_Ace

iTrader: (18)

Yeah, i forgot to add that to the above list of things tried so far, idle screw is closed all the way already.

Well i will check the AFM but when i had it off the car it was closed from what i could tell.

Also, how would that effect the idle speed if it has nothing to do with how much air gets into the engine? just the fuel?

cr7684

iTrader: (42)

No it's for the air flow & your presure sensor with the ECU works the set fuel/ign maps... Also the WILL closed when the car is NOT RUNNING...

Texas_Ace

iTrader: (18)

I see, and I am 99% sure mine closes all the way, i didn't look at it for this purpos but i had it off the other day and it was close if i remember right.

Could the voltage on it be off? I happen to have another AFM laying around, i just don't know if it is an S4 or S5 AFM. I might try putting that one on and see if it changes anything.

white_charisma

have you tried adjusting your tps, most idle problems can be resolved by doing so, takes very little time and could take care of this. youre going to need a multimeter if you dont have one and as previously stated you have an a/f screw located by your map sensor than can bring your idle down as well

cr7684

iTrader: (42)

No you can not use the S5 AFM on the S4 it wont plug up! You said that you had if off and the door was closed by that you mean you had the air fitter off the AFM and the door was closed with the car RUNNING? Or you took off the AFM with the NOT running? You should check it with the car RUNNING & the air fitter assy off this way you can see how open is the door because there is a adjustment screw for the S4 AFM!

Texas_Ace

iTrader: (18)

Another thing i have tried, adjusted the TPS many times.

Now this screw on the AFM is new to me, where is it and how do you adjust it?


Well then i will try plugging it in and see if the connector fits. if so i will see if it helps anything.

And yes, when i tested mine it was off the car and closed. I will try it with the car running tomorrow. If i can't get it down i am just going to take it to the shop and see if they will accept my left arm as payment as i need the right. lol

turboIIrotary

iTrader: (9)

there is a throttle stop screw on your throttle body check to see if it isn't opening your throttle a little

Texas_Ace

iTrader: (18)

Well when i pulled the TB is was closing all the way but with everything i have messed with it is always possible i guess, another thing to check.

white_charisma

its located on the right side of your engine bay (passenger side) right next to the map sensor, little black bracket lookin thing, with a hole and if you look into it there is the screw, flathead i believe, and counter clockwise lowers and clockwise raises i believe

Texas_Ace

iTrader: (18)

So it's not on the AFM? Are you talking about the boost sensor?

RotaryCyphaX

iTrader: (1)

Is the engine stock?

J-Rat

iTrader: (2)

Was the timing tampered with?

dkwasherexd

iTrader: (8)

the idlee screw on tob of the throttle body, its in the center use that to adjust the engines idel speed. its easy to do.

wrankin

You are getting air in the engine somehow. So it's not the AFM. Did you eliminate the wax pellet warm up or are you still running coolant lines to the TB? Have you checked the BAC valve?

-b

cr7684

iTrader: (42)

What i'm talking about is ON THE AFM it's a flat head screw i'm not here saying for sure this will help but it will be one less thing off the to do "check list."

Just because your getting "air flow" does not mean "It's not a bad air flow metter" and like I said the S5 will not plug up to your S4 wire harness.

Also the "BAC" is a good place to look at BUT JUST GET ONE THING DONE AT A TIME and you should make notes for your self just in case you do drop it off at the shop you will have a "CHECK LIST" it will make things easy for the next set of hands .

Chuck

iTrader: (2)

I've always tried the simplest things first before I start twisting and turning every screw I can find.

Have you checked the tension on the accelerator cable?

88t2romad

This is what I'd check....does not matter if your TB CAN close all the way when its off the car.....more inportant if it IS closing when it is on the car. Check the cable and make sure nothing is getting in the way of the TB cams, springs and whatnot.

toplessFC3Sman

iTrader: (1)

Timing or fuel problems will affect your idle, but not enough to make it go from 750 to 2000 RPM. The major problem here is that extra air is getting past the TB somehow. If all of the gaskets are good, vac lines are hooked up etc, and you dont have any leaking or missing block-off plates, then the air is escaping around the TB plates.

There is not only the hard-stop adjustment screw for the primary throttle (single plate), but another one for the secondary throttle plates (double plates directly below the single plate) that may be open too far. This was the case on my car, and had been causing a high idle problem as well.

If none of the other suggestions work, pull the TB off, remove or adjust everything that could prop the throttle open so that the throttle blades are solely held in place by their bores. Then, loosen all of the screws and vibrate the throttle shaft to try to get the plates to seat firmly in the bores. Tighten up the screws, and then set the hard-stop adjustment screws so that they hold the throttle plates open just barely before the plates hit the bores so that they dont stick. Return the rest of the stuff (thermowax, fast idle cam etc) to the way it had been.

Texas_Ace

iTrader: (18)

Yes, as far as i know it is. It was rebuilt not to long ago before i bought it, i don't think they ported it though.

The timing has been adjusted but i reset it per the FSM and even if i retard it the RPM's still don't get anywhere near 750, about 1500.

Yep, it has been fully closed for quite awhile now, one of the reasons i am lost. lol

Yeah, i just can't for the life of me figure out where that air is coming from.

The Thermal wax has been disabled by adjusting it so it doesn't ever touch the cam at all. it was not working right and keeping the TB open a little. the coolent lines are all still in place it just doesn't engage the cam.

BAC valve appears to be working fine, I tested it off the car and it worked but i made sure by pulling the air hose off the intake and then blocking both sides and the idle didn't change. So that is not the problem (i was hoping it was too)

I see i will look at the AFM and find that screw. who knows.

As for the other AFM i have, i don't know if it is a S4 or S5. It could be either. So if it plugs in it must be an S4 right?

I havent actually checked it per se, but when i was hooking it up it seemed to be a little too lose vs to tight. But that is very possible. I will take it off and see if it does anything. Good idea.

i am going to disconnect all the cables from the TB and see what happens, i looked at them but never really tested them.


Yeah, i also thought this might be the case so i pulled the TB awhile back and checked it out. Found the Thermowax was bad and figured that was the problem. so i made sure the plates closed and put it back on. It lowed it a little but not much. I might need to pull it again if nothing else works and do it like you suggest. At this point i am out of ideas. As soon as the rain stops at least i have so things to try.

Thanks for all the help everyone, will report back after i try these things!

toplessFC3Sman

iTrader: (1)

Check and make sure that both of the throttle hard-stops are backed off enough. The secondary plates have their own, separate adjustable hard stop that may be out too far.

The S4 AFM is much more square than the S5 one. It has a flapper door that pivots inwards with more air flow. The S5 AFM is pretty cylindrical, and has a tapered plunger (IIRC, i've only seen pictures) that gets pushed linearly back. It doesnt swing. I dont know about the plugs interchangability though.

Texas_Ace

iTrader: (18)

That was it! The sec plates stop screw was out too far and that is what casued the high idle.

It is now down to ~800 (is jumps around a little all the time but it works, not the TPS, it is adjusted right).

So now i am just needing to get it ready for inspection. I took it for a test drive and i noticed that when i would get on the gas and then let off I could hear some poping from the rear end, is that from the exahust?

If so i guess that means it is not ready for inspection quite yet.

Time to search and see what i can find about getting ready for inspection, i know it smells bad out the exahust.

Thanks for the help everyone!

cr7684

iTrader: (42)

Good for you brother enjoy......