Rotarytard

Hi Guys,
I just put my car back together and I'm getting a bouncing idle when it warms up. It bounces from 500 to 1200. I went so low once, that the car just died. I adjusted the idle and now it bounces from about 800 to 1500 in order to prevent it from dieing.
The mods are as follows:

new street ported motor
bnr stage 2
pfc
boost controller
ac removal
intercooler
intakes
3 inch pipe all the way out
intakes

The power fc was tuned before i had removed the ac and also before i installed the ported motor. Do you guys think that the idle is bouncing because the ecu is not yet tuned to the ported motor? I can't tune the motor until i break it in and change the oil.

Also, can it be because its low on coolant. I just filled it up and burped the system but i'm sure that there is still a little bit of air in there some where.

any help is appreciated.
thanks
Tony

Rotarytard

nobody knows?

andre sinclair

iTrader: (36)

If motor is solid (built properly) check you TPS sensor

No-Pistons-TT

what is it boosting at ;at idle??????

Rotarytard

andre,
i'll check it and let you know.

no pistons
i haven't tried boosting it yet. is it safe to boost it at idle when the motor has about 75 miles on it?

note:
it idles smooth for a while and about 3 minutes after normal temp, it starts to bounce. after it bounces for a while, it'll idle smooth for about a minute and repeats itself.

thanks guys

teamafx

iTrader: (4)

its common for this to happen with the ported motor, wait until it gets tuned. There is a guy local I had straighten mine out

luizajeff

From my reading it common with PFC's on many FD's and even without if there has been some mods. Even my Honda civic will idle hunt sometimes when it's warm, not the end of the word, just a pain for us rx7 perfectionist freaks!

rizzxx7

iTrader: (4)

I think thats perfectly normal to do that, mine does the same thing and it straightens itself out.

jeremyb

So there's NO correction at all? Teamafx may have a point. I'm in the current process of a rebuild and street porting my motor and I also have a PFC. I'm sure there's a way to keep the idle solid. And idle HUNT should not be normal. Idle hunt is the computer trying to find a set speed but a sensor or mechanical component is throwing it off. Idle bounce is what most people refer to as normal. Putting monster cams on a V8... I would refer to as idle bounce... not idle hunt... an unplugged boost map sensor (example) is idle hunt to me. IMO there's a difference and I do think it can be corrected.

Jeremy

Rotarytard

I'm going to check my tps with a voltage meter and see if I can set it to another setting. I'll this posted. The bouncing is precise, I'm sure its an electrical problem.
Tony

teamafx

iTrader: (4)

well if the car was tuned for a non ported motor and you havent had it retuned trust me it can be tuning. I had the same issue, checked tps, tore down the turbo setup, Upper and lower manifolds, etc. at least 6 times to see it was me, and we retuned it finalyl and got the idle straight.

Mr rx-7 tt

iTrader: (5)

Check the compression...it isn't "normal".

GoodfellaFD3S

iTrader: (213)

No need for a voltage meter. On your PFC commander, go into the settings area, there is a screen which lists voltages for many sensors, to include your TPS.

I agree that this is most likely a tuning issue. I doubt it's the engine. Mine does something similar, and we were able to tune it out, but as soon as the weather changed here in NJ it went right back to it's old tricks....

RXJoey

Not sure if this will shed some light on this, but my FD does the same thing now. The only thing that has happened since everything was fine, was I had the recall done for the feul hoses, the ones that makes the fan run after you shut the car off it the coolant/feul gets to a certain temp. Many hoses messed with during this recall. If that narrows it down for you great. I am gonna keep my idle problem as I would probably get 3 more problems if they rip everything apart again. The AWS is also screwed up, used to pop right to 3k on start, now it either doesnt do it at all, or it starts at 2000, then slowly goes to 2750, then back to 1500... oh well.... such is the joy of owning an FD.

Peace

RXJoey

Rotarytard

Hey Guys, thanks for all of the help. I haven't had a chance to look for the problem because I've been working non stop. I'm sure I'll have a solution to this problem and hopefully this thread will help fd owners in the future. I'll keep this updated.

akiratdk

check your tps sensor!!~~~ this happened to me as well... and when I adjusted the tps... it purred.....goood~~~~ hope this helps~~

kraked

My idle is funky too, drops down real low when i blip the car (when its warm). Havent had time to adjust TPS yet but I suspect thats the problem.

I am a new fd owner (month) so i was wondering, for those that HAVE adjusted the TPS before, how long does the job take?

alberto_mg

while this might not be related to all the people posting on this thread, you guys might also want to check the dashpot. it's on the throttle body. it keeps the car from dying when you suddenly let off the trottle. search on dashpot for pics/info.

kraked - i think the dashpot is your problem.

kraked

I've actually adjusted that already, it seem to help a little but it still does it

Quickfini

iTrader: (6)

Hmm, my car has an erratic idle as well as of late. After one nite of hard driving, the idle started going funny on me. Sometimes it'll rev from 1000-1500, but under electrical load (AC), it seems to help things out, but not always. The car drives fine, but just my idle is bothering me.

What should the voltage for the TPS be normally?

kraked

Sounds a lot like what my car is doing, sorta embarrasing when it stalls infront of everyone lol

Theres a lot of talk about adjusting TPS and youll find a HOWTO easily on this forum

I'm going to adjust mine in a few days and I'll post here the results.

teamafx

iTrader: (4)

Just and update, I found a leak at the oil injector nozzles when I was working on mine, and discovered my primary injector insulators were gone and there was air leaking.

impactwrench

Lean at idle could cause the hunt

technonovice

I had the same symptom and it turned out to be a blown lower intake manifold gasket.

cwareham

Rotarytard - Did you ever get this fixed?

Thanks
c