ooEfiniRx7oo

ok, recently I started to have this problem with my 93 rx7. At cold start everything was fine but after I drive for awile and let my car go on idle, my motor starts to jump around (700rpm~900rpm) and then it just looses it and dies out. Idle was no problem untill I installed the RE Amemiya intake and Greddy IC pipe kit. I doubt that those things are effecting the idle, but what else could it be? Its just started to happen all the sudden after i installed those two items....

and yeah, I've searched around on this forum about this issue before I placed this thread"

Thankx,

John
San Mateo,CA

Roar 629

tps inspec? all manifold gasket good? i live around sf, i can come down help

DaveW

Is it possible that some crud that you dislodged installing those items got wedged in the throttle plates? If the throttle plates were not closing correctly, that would cause idle problems.

ooEfiniRx7oo

thankx guys, im gonna go check every vac. hoses and the throttle area again....*ugh!*

jd to rescue

iTrader: (3)

Hate to sound like a broken record but check your ground wire contacts. This is often a symptom of poor ground contact.

DamonB

You're wasting your time if you have not checked the FPR solenoid and vac lines. This is only active during hot starts and gives a lumpy idle when the engine is hot; during cold starts the idle is fine.

1QWIK7

iTrader: (33)

prob the isc, get a digital meter and test the ohms of the terminals

clayne

It's not hot starts.
It's not a ground issue.

What did you do with the airpump connection when you installed the intake?

ooEfiniRx7oo

Ok, the problem is fixed.

1) tweaked the idle with the little screw which is under the greddy elbow.
2) tweak the valuve openning with the little nut and screw which is located right beside the throttle.

now, with head light, AC fan, Cooling fan and the radio on, the idle is stable...at 900rpm.

Ripzta

I've got a real bad idle issue. When cold the car idles around 1100rpm until its warm. When warmed up the car idle drops to a normal 750rpm but sometimes when i rev it abit the idle goes up to 1100rpm and stays there again then drops back down after a while.

Clayne: What did you do with the airpump connection when you installed the intake?

I took my airpump hose off so now its sucking in the air from the engine bay.The hose wasnt connected to my intake in the first place so i just took hose off. Will taking the hose off affect the idle? I can't seem to fix this problem.

Will adjusting the throttle screws help?

Ripzta

Just warmed up the car then. Tried adjusting the screws but its already loose as it can get. The idle never seems to drop below 1000rpm, it stays above usually 1100rpm but sometimes is it 1400rpm. That way to high.

Ripzta

I did replace my fuel pump a while ago before the rebuild. Dunno if this could affect the idle to?

Ripzta

I did replace my fuel pump by a non rotary mechanic a while ago before the rebuild. Dunno if this could affect the idle to?

jamesuncw

I had the same problem, streetported with pettit ecu. It used to idle at 1300-1400. Adjusted the AAS and the other one. I got it to idle at 1100 with AAS all the way closed and the one on the top of the TB all the way out. However, when I either turn the parking lights on or it will also randomly drop to around 500. Gonna play with it some more, but I can't get a steady idle.

ooEfiniRx7oo

I just adjusted the idle with the notch which is located under the throttle elbow and also the little nut and screw which adjust the opening of the batterflys. I just got the ratio of those two and idle remains 800rpm with ac/fan/head lights on or off.

fortch03

I am having the same low idle problem. When I start the car and it's cold, it idles normally. However, after I get going a bit, the idle will be lower then the usual. I dunno

RotorMotor

iTrader: (5)

i fixed my jumping idle by changing the intake gasket on the LIM..... i had teh same problem as you

clayne

For all people with PFCs, do the idle reset routine before even troubleshooting idle issues.

cavellm

Damon, where is the FPR solonoid? I looked in the manual but couldn't find reference to it. Would this not apply if an aftermarket pressure regulator is installed?


And also, how do you check to ensure it works correctly?

DamonB

It's on the solenoid rack; the one closest to the firewall.

I'm not actually certain. I would expect most would bypass it if they have an aftermarket fpr.


The stock fpr solenoid is only active for hot engine starts and only affects idle quality. During a hot start the ecu triggers the solenoid which is connected by a vac line to the stock fpr on the fuel rail. Many people bypass the stock fuel pressure regulator solenoid altogether by running the vac line from the fpr directly to the manifold. The thinking being that if the fpr solenoid were to die or break you won't have to worry about fuel pressure problems. The downside to this is lumpy idle for the first few minutes after a hot start.

ooEfiniRx7oo

I just adjusted the idle with the notch which is located under the throttle elbow and also the little nut and screw which adjust the opening of the batterflys. I just got the ratio of those two and idle remains 800rpm with ac/fan/head lights on or off.

I just adjusted the idle with the notch which is located under the throttle elbow and also the little nut and screw which adjust the opening of the batterflys. I just got the ratio of those two and idle remains 800rpm with ac/fan/head lights on or off.