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Idling problems...EA82T, '87 RX


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The RX is having problems idling. The engine stumbles like its about to die and has trouble idling above 1000rpm. Driving home from work tonight it stalled once and at every light I had to keep my foot on the peddle just to keep my car above 1000rpm.

 

When I got home and pulled into the driveway, the car's idle dropped to about 200rpm then died. When I re-started it it rose to about 600rpm then stumbled down to about 400rpm but I kept it running long enough to get under the hood. Once under the hood I attempted to increase the idle by adjusting a screw at the top of the intake manifold, right behind my throttlebody. Turning it clockwise killed my car, so I i gave a few turns counter clockwise and started the car. It seemed like the idle had picked up to about 900rpm, so with it running I adjusted the screw until it got up to around 1100.

 

The test drive around the block went well. At the first few stops, as soon as I let off the throttle, the engine would drop to 1100 and hold idle until I accelerated again. Until my last 2 stop signs to get home. By the time I pulled into the driveway the car was again idling at around 600rpm and wanting to die.

 

Durring all this Im monitoring my boost gauge, and i notice on decel my gauge is at -20in but at idle its falling to -15in or so. IIRC that would indicate a vacuum leak somewhere, but so far I am unable to find any.

 

Oh, and this is with the RX back to stock. No intercooler, bypass valve or boost controller.

 

Im probably going to pull it into the garage tonight and take a close look at everything to make sure somethings not undone... i also got another knock sensor I wanna try out (Thanks SuberDave!!). We'll see what happens...

 

-Brian

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So i removed the AIC Valve and checked it out. I cleaned the mating surface, the gasket looked good. So i put it all back together at lunch and the car seems to hold a better idle when cold. But when it warms up, it still has a problem idling.

 

If i let the throttle drop, it will hold steady at 1000rpm for a few seconds, then slowly drop, until its barely idling at 200rpm then dies. It stalled once on the way home again today, and at every stop i had to brake while applying pressure to the gas peddle just to keep the car running.

 

The car is no fun anymore. Anyone wanna buy a RX?

 

-Brian

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Mine used to do that RANDOMLY....one day idle at 2000...the next NOT at all....sometimes JUST right at 1000 where I want it.

 

It was always random.

 

Now it sits at 1000....or 1100...or 1200....as high as 1300....randomly. I dont care. It idles.

 

Yours sounds like a leak. Spray engine intake tract with some kind of flammable spray from can while running and you will find the leak if...

 

A: car dies more on certin spot.

B: idle increases on certin spot.

 

Then you have found leak.

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Will ive been doing that. Ive used that method to look for leaks probably 4 or five times. With Carb cleaner, then today at work with some throttlebody cleaner (dunno if theres a difference) but both were unsuccessful.

 

I just got done wrenchin on the damn thing for about 2 hours. Removed the temp sensor and cleaned its connections. They were pretty corroded, and I used a tiny flathead screwdriver to scrape everything away, i also bent the contacts a tad to make sure they had a nice snug fit.

 

After putting everything back together, it was still not idling right. So I started moving hoses around to see if maybe i could locate the leak that way. While messing with the plumbing for my boost gauge and my BPV (which is now plugged) i thought I heard the idle change so I removed the vacuum line to my boost gauge and plugged that.

 

Then I took the car for a drive around the block. Its like nothing changed. Car still has a hard time holding an idle and it stalled once.

 

So then i started to try to clear my ECU codes. Did a code check and found out that code 23 was added to the other 4 codes I had stored, so now i have 5. So then i was like "WTF lets try to clear them" Since i had replaced half the things that were throwing codes.

 

After dicking around with the ECU, now when i try to pull codes my LED just blinks twice.... over and over and over again, would be Code 20 if it existed, but i dunno if i broke it or fixed everything. Whatever I did, it sure didnt help my idle at all.

 

Eli... $1800 for the RX with the intercooler setup and stereo.

 

-Brian

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Yours sounds like a leak. Spray engine intake tract with some kind of flammable spray from can while running and you will find the leak if...

If you use carb cleaner or anything of the sort be sure not to get it on the alternator or distributor. anything flammable will normall react with electricity. maybe check out the local costume shop for a fog machine, those are safe; or you could hold a can of compressed air upside down where it creates very dense water vapor in a visible gas form.

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you can give it back to me. I know how to fix cars.:grin:

 

kind of a rule of thumb. when a car throws a ton of codes at you the components are probably not the problem. most likely common problem. like a bad ground, reference voltage shorted, open or somewhere in the middle.

 

you have a volt meter now right? start checking voltages TPS, O2, ECT, MAF. you need to know whats good and whats not. the boot from the maf to the turbo is not split right? I know you modifed the air filter setup. quite often that puts stress on an already old and brittle intake boot.

 

just some thoughts as I cant really diagnose what I cannot see.

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I replaced the rubber piece between the MAF and Turbo because my old one was split. The new one doesnt look to be split, and it doesnt show any signs of leaking.

 

The ECU isnt throwing any codes now. 2 blinks of the LED with the black connectors connected.

 

No Volt Meter, so I cant test anything.

 

This morning the car stalled and wouldnt idle again. It only happens when the engine is warmed up, with it cold out the car idles at 1500rpm. Warmed up it wants to idle at 1000rpm but just cant.

 

-Brian

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YEah thanks Capt. Obvious :-p

 

I was looking at the FSM .pdf i got, and it shows to idle adjustments. one for cold idle and one for hot idle. The screw for hot idle is gone, and plugged with a bolt. I was thinking that might have something to do with it.... but its been setup like that since i owned the car.

 

-Brian

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Ok then it shouldnt be effecting this problem then, i hope. I removed the bolt and replaced it with a new one. I didnt have any teflon tape so i used electrical tape, which didnt work out well at all.

 

Anyhow, problem didnt change at all. What are some components that are only effected when engine temps warm up?

 

-Brian

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  • 2 weeks later...

I had a similar problem when i bought my rx. It turned out that somebody had messed with the maf spring preload, so it at had so much strength it would shut the flapper door and die. It took me a few days of fine tuning to get it set right. It seemed to be okay cold because it idled high enough to keep the door open on the maf. My intake is modified though (broken, duct taped, and escort airbox...well half of it). it runs fine now though. just a thought...

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just a thought but even though my engine is kiiiinda....bad haha it does that idle problem too. Dont listen to me though since i dont know JACK and need to learn. its most likely due to the fact that i think one piston ring on the 3rd cyl is damaged perhapes? or sumthin, low compression in 2 cylinders but when cold the engine idles quite high, around 2000~1500 but after warming up it starts struggling, then i would have to hold my foot on the gas at while at a stop to avoid it dying. im surprised u havnt come by to check it out yet, maybe could get some ideas? i jus have it chillin till winter break and i live basically 2~3mi from ur work....:banana:

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