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Ok... yes i did search and read LOTS. This is for absolute verification before i start doing stuff because i am not exactly mechanically inclined.

When i am driving... usually only when the engine is cold and i coming to a stop at a light or stop sign. I put the clutch in and the rpms QUICKLY drop down to like 100-300 and then dip... then come back down... then dip up... then come back down... then they will settle eventually.

Sometimes it comes VERY CLOSE to cutting the engine... like all the dash lights will come on showing that the engine is off.... but it just barely recovers.

It is also like this when i just start the car... it dips down VERY LOW... then goes back... back down... then back up.

It also happens if when the car is idle and i hit the gas to rev the engine.. it goes up... comes down nearly stalls, goes back up.

NOW!!.... WHAT I HAVE READ!

I have read that a pretty common problem is the IACV... I know that you can clean it as i found the writeup on it. Do you think that is what it is? Makes sense in my opinion.

Is it very hard to do ?

ANDDDD LASTLY...do you think it could be something other than the IACV?

Thanks so much all my g20 peeps.
 

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Could be the rear O2 sensor. I had, what sounds like the exact same problem, although you don't have a Service light on do you? Anyway, after I changed the O2 sensor....ran like new. I believe the code is P0140 for the sensor. Hope that helps.
 

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Both times my alternator went, that was a symptom. The one time when it was the most like you describe, the connecting screw on the alternator was broken and it was arcing the current to the wire. When I would slam on the brakes, the wire would move and it would break the arc, causing the car to almost die. Then when the motion subsided, it would reconnect and continue to run properly.

I'd take it to AutoZone and have them hook it up and check your alternator (and probably your battery by now too, if this has been going on for any length of time).
 

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I have this same thing happen when my car is cold. But it doesnt do it all the time. Also P10's dont have a rear O2 sensor that im aware of. Its really not that hard to clean the IACV, Just be careful and dont force anything. You also might want to read up on and check you base Idle. If you havent done all the normal tune-up stuff recommended in the maintenance thread then I would recommend doing that also.
 

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how cold is it where you are? does it only happen on initial start up?

Mine does it when it's very cold but it's due to the thick manual gear oil. Once the transmission warms up, it goes away.
 

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Are you getting a check engine light for the IACV??? On my P11, I took it out and then put it back in (w/o even cleaning it) and my check engine light came on, and my car did the same thing, rpm's dipped, and sometimes it even stalled. I tried everything, but ended up going to the dealer and had them hook up a consult to it and reset the IACV or whatever, and after that it was fine.
 

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sou8nds like either a maf or iac. the maf went bad on mine and it did the same thing.
 

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There are a lot of things that can cause unstable idle, a few are:
Injector
Spark Plugs
Fuel Pump
Heated Oxygen Sensor (California Models Only)
Oxygen Sensor
Air Intake Leak
Compression Pressure
ECM
ECM Harness
ECM Power Supply and Ground Circuit
Adjust Idle Screw
Mass Air Flow Sensor
Intake Valve Deposits
Ignition Wires
Idle Adjustment Screw Clogging or Throttle Body

& Many More

That is all I could possibly think that could be happening as of now. I may bring it in for diagnosis however I think I will play around with it till I fix it for now.

EGR - Exhaust Gas Recirculation Valve - The EGR valve controls the quantity of exhaust gas to be led to the intake manifold through vertical movement of the taper valve connected to the diaphragm, to which vacuum is applied in response to the opening of the throttle body.

IAA - Idle Air Adjusting Unit - The IAA is made up of the IACV-AAC valve, IACV-FICD solenoid valve and idle adjusting screw. It receives the signal from the ECM and controls the idle speed at the preset value.

IACV - Idle Air Control Valve - The IACV regulator provides an air by-pass when the engine is cold for a fast idle during warm-up. A bimetal, heater and rotary shutter are built into the IACV regulator. When the bimetal temperature is low, the air by-pass port opens. As the engine starts and electric current through a heater, the bimetal begins to turn the shutter to close the by-pass port. The air passage remains closed until the engine stops and the bimetal temperature drops.

MAFS - Mass Air Flow Sensor - Measure the intake air flow rate by taking a part of the entire flow. Measurements are made in such a manner that the ECM receives electrical output signal varied by the amount of heat emitting from the hot wire placed in the stream of the intake air. When intake air flows into the intake manifold through a route around the hot wire, the heat generated from the hot wire is automatically controlled to a certain number of degrees. Therefore, it is necessary to supply the hot wire with more electric current in order to maintain the temperature of the hot wire. The ECM knows the air flow by means of an electrical change.

TP - Throttle Position Sensor & CTP - Soft Closed Throttle Position Switch - The throttle position sensor responds to the acceleration pedal movement. This sensor is a kind of potentiometer which transforms the throttle position into output voltage, and emits the voltage signal to the ECM. In addition, the sensor detects the opening and closing of the throttle valve and feeds the voltage signal to the ECM. Idle posisition of the throttle valve is determined by the ECM receiving the signal from the throttle position sensor. This one controls engine operation such as fuel cut.

Basically the issues you are having can be caused by a multitude of things. I suppose if a shop can't diagnose it for you just start from the bottom of the list of parts to replace and tell us which one was defective :naughty: .
 

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Mine does the same damn thing and I've been trying to figure it out. I was actualy just going to post about it when I saw yours. I'll check my alternator when I go into work on Tuesday. I already priced an O2 sensor and a MAF. Does a 94 P10 have 1 or 2 O2 sensors. It lists two but isn't it an OBD1 car?

Oh an no check engine light. That's what was stumping me if it's a maf or an O2.
 

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Well, I'm not meaning to jack someones thread but I tested my alternator today.

Good battery.
13.8v, 80 peak amps, and good diode pattern
 

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I will be ordering both oxygen sensors and replacing them. That is my next move right now. Also replacing front upper control arms but that isn't going to help this issue. I hope I get better gas mileage. I will be messing with the IACV if the oxygen sensors don't help. Then re-grounding my MAFS or buying a new one and harness.
 

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Mine has been acting similiar. It seems to vary between fluctuating with a high idle, and a low idle that stalls out in neutral. I originally took it to Tunex and they told me I had a bad IACV, so I replaced that on my own. All it seemed to do was cause the car to stall more with less fluctuation of the idle. After I replaced the IACV I reset the ECU to see what new codes would come up - the MIL hasn't came back on, but obviously something it still wrong with it. I really don't want to drop $$ on a new MAF sensor or O2 sensors if it's not going to solve the problem - already feel like I might have wasted money on the IACV. Anyway, let me know what works for you and I'll let you know if I figure anything else out. Mine is an '01, but sounds like it could still be the same problem.
 

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Now that I really am thinking about it, my car used to stall out until I replaced my air intake with a cai. It has to be the MAF. I will replace that before the Oxygen sensors.
 

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Guys, I've got the same issue going on right now with my 2001 P11. When sitting, it seems fine but as soon as I start driving and shifting, it stalls in any gear. I've bought the new IACV and had it installed. Thought that was going to fix the problem but when I drove off from PEPBOYS, the car stall as soon as I drove around the corner and died. I quickly turned it back on while coasting and brought it right back to PEPBOYS. I'm having them check the MAF and O2 sensors. When I get more information, I'll keep you all updated.
 

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saltima said:
Guys, I've got the same issue going on right now with my 2001 P11. When sitting, it seems fine but as soon as I start driving and shifting, it stalls in any gear. I've bought the new IACV and had it installed. Thought that was going to fix the problem but when I drove off from PEPBOYS, the car stall as soon as I drove around the corner and died. I quickly turned it back on while coasting and brought it right back to PEPBOYS. I'm having them check the MAF and O2 sensors. When I get more information, I'll keep you all updated.
That was happening to me for a while, I put in a CAI and it removed the complete stall. Now it dips around sometimes almost killing itself. I think it is the MAF but I don't know for sure.
 

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I was talking to a buddy who drives a Nissan 240 and he was having the same issue. He said he sprayed the MAF with carb cleaner and it resolved the issue. I asked Pepboys to spray it but they won't. They would rather have a complete diagnostic so I said, fine. Again, I will keep you all informed.
 

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Well one of your problems is taking it to PEPBOYS. Sorry if anyone on here works there but when you go to change the rear diff fluid in a car and drain it but can't get the fill plug out and put the drain back in and send it out w/o anyfluid in the rear end......Yeah, that's one of the stories I have heard about there.
 

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That can happen to you from any where, such as my parents getting a free oil change. When they meant a free oil change they drained the oil and didn't put any back into the car. The engine seized later. It was weird hearing a car melt itself together. It was a Mitsubishi Montero, the shop I don't remember I would have to ask my parents.

imo Mitsubishi's are crap.
 
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