I have a 97 2G automatic. It runs fine, has power, and idles smoothly but sometimes it suddenly shuts off when Idling. The engine shuts off as if I killed it with the ignition switch. It starts up immediately by turning the key. This behavior only seems to happen within the first 30 minutes of starting the car. Some of the suggestions I read for the 95 1G were to check; Cam sensor, IAC sensor, and ECU.

I don't have much money right now(I can spend $50 this month after rent and bills) I can't afford the usual "lets change everything one at a time until the problem disappears". I need ways so I can test to isolate what is wrong so I can spend the little money I have in the right way.

Ask me any questions if its going to help you diagnose my problem.

Have you checked the cel codes?

Could be one of your sensors going out like the cam or crank position sensor!

Could be something stupid like a loose wire as well!

I'm just going through this now and it turned out to be the cam angle sensor. P0340, it would be running fine and then just stop like it was turned off. I found that I can plug in the cam angle sensor, start the engine and let it run for like 2 minutes and then unplug the sensor and it will run perfectly. I ordered a new sensor from JNZ tuning for $63

Thanks rough and estoyaqui30 but the car is not throwing up any codes. One thing I did discover is it is a misfire. Now the problem is getting worst so that I can feel it misfire while driving. The misfire during idling is causing the shutdown - when driving, there is enough momentum to keep the engine running.

Things I've replaced:
Spark plug wires
Spark plugs
Fuel filter

The symptom still is: sudden shutdown during idle due to periodic misfire. Misfire usually occurs in 30 minutes of driving. Rarely if any after driving many hours. Otherwise engine runs smooth and idles smooth at 400~500 rpms. Car has power and runs at a normal temperature. The car throws no codes.


I'm thinking the ignition coil is failing. I can't think of anything else that would cause this symptom.

Do the 2G's have a ignition transistor / igniter? I don't know if that's the correct term as it's been a long time since it happened but that's what was going bad on my 1G when it did the random dying stuff. It turned out that it was getting hot and would shut the car off, but it never died while actually driving.

Plus +1 it's on the top of the intake manifold close to the center between theinjectors and valve cover

^No transistor on top of intake. Maybe you're thinking turbo.

Anyway things I've replaced:
Spark plug
Spark plug wires
Distributor

ISC
TPS
2 sensors on the intake manifold I haven't been able to identify
fuel injectors

Camshaft sensor
Crankshaft sensor

I can only think of two other things;ECU or fuel pump. I doubt it's the fuel pump because the idle is smooth and it drives good on freeway - I would expect a failing pump to produce a rough idle and/or starve the engine on higher speeds. I also doubt the ECU since nothing else is going wrong.

I am running out of the low cost options. Anyone had same situation and solved it?

Check your o2 sensors. Sounds like one isn't cycling like it should.

Dsmkauai said:

Check your o2 sensors. Sounds like one isn't cycling like it should.

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I've replaced my O2 sensors 4 years ago, besides, I've never heard of an O2 sensor causing an engine to stall.

Sure can. If it's not cycling and the ecu isnt seeing what's happening (rich/lean) and able to make proper adjustments like it's supposed to. The engine is running too rich, it may stumble or even flood out and stall at low speeds or idle. Happen on one of my old jeeps years ago.

Dsmkauai said:

Sure can. If it's not cycling and the ecu isnt seeing what's happening (rich/lean) and able to make proper adjustments like it's supposed to. The engine is running too rich, it may stumble or even flood out and stall at low speeds or idle. Happen on one of my old jeeps years ago.

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Please don't give excessively general advice since it will confuse anyone with the same problem. I'm sure your honest and it happened on your jeep, but running too rich to stall a car has symptoms such as the idle is rough, you can smell the gasoline and hard to restart engine. I clearly outlined the symptoms of my car and running that rich simply doesn't fit. Furthermore, this car is a 2G eclipse GS which in my experience and what the majority wrote on this forum don't stall when the o2 sensor is out - they get bad mpg and send out codes but otherwise run fine.

Solved: Faulty ECU

I suggest everyone get a spare ECU that matches their car. Ideally shop around for one before problem develops. I bought mine used of of Ebay for under $50. There is no clear way to diagnose ECU problems other than swapping one out for a good one and seeing if the problem goes away. I could have saved a lot of money, time and labor if I replaced the ECU first. The ECU can affect a vast amount of the cars operations; A sticky shift problem on the automatic transmission was also cured after I replaced the ECU.

Hence for anyone with the same type of symptoms I would suggest checking parts in this order.
Symptoms:
Car infrequently and randomly stalls when in idle and infrequently and randomly misfires when driving. This happens when the car is hot or cold, immediately or after several hours driving, driving over hard bumps doesn't make the car stall nor hard turns, Car restarts immediately. Idle is smooth and car has power at low speeds and high speeds. Car runs at normal temperature.

Check:
1) loose wire - unlikely since bumps don't affect car but checking wires is easy and cost nothing.
2) ECU - the most likely culprit when the symptoms have no rhythm or reason.
3)Camshaft sensor - I read many posts of Camshaft sensor starting to go bad give of similar symptoms
4)Crankshaft sensor - Same effect as above.

Unlikely but check:
When the car stalls, do you smell a little gas? if so it means no spark happened on last cycle so check electric system otherwise check fuel system.
Electrical
5) spark-plugs - These need to be regularly replaced anyway.
6)spark-plug wires - can cause misfire but usually the idle is rough because the misfires are frequent.
7) coil - causes symptoms like bad wires - idles rough because of misfire.


Fuel(All very unlikely)
5)ISC
6)TBS
7)Fuel filter
5) fuel pump
6) Fuel injectors