When my 99 civic is warmed up RPM jumps stalls and eventually dies down. If I starts again I have to hit gas or it will die down again. If engine is cold runs fine.

 

Sounds like ICM

http://techauto.awardspace.com/ignition.html

 

Just went to Autozon and got these codes
p0303, P0304, P0300, P1399
These codes are for misfire

 

Again... ICM is the ignition control module inside the dizzy... Take it out and have autozone test it...

 

Took ICM to Autozone. Its not ICM all test passed. What else?

 

I had 3 gallon of gas sitting for 5 years. Without thinking put it in my 99 civic gas tank mixed with 7 gallon of new gas. Since then car is stalling and now check engine light is on. Took it to Autozone and got misfiring codes. When car gets warmed up dies. Cold engine starts.
What could be wrong? Where should I start?

 

you probably should drain as much gas as you can, then refill with new gas, and use the fuel system cleaner (that you buy at schucks), and if the problem keeps happening, use motor flush, and do a tune-up, oil change, coil, spark plugs etc...

 

Unplug the primary O2 sensor to see whether this prevents the problem.

 

Judging by the fact that it only happens at operating temperature, I would be pointing the finger at the o2 sensor. The o2 doesnt send signals to the ecu until it reaches operating temperature and the o2 could be telling the ecu bad signals making it run rich and hard to start...

 

Just some minor corrections.

The O2 sensor sends signals to the ECU all the time. The ECU just ignores the signals until the ECT sensor indicates the engine is warmed up.

In general, an engine will run fine on a rich air/fuel mixture. A lean air/fuel mixture, however, will make the engine run poorly. When a bad O2 sensor has the latter effect is when performance suffers.

 

Related threads merged

 

Went to mechanic and did compressor test. He said needs to take out had and thinks its valve might be damaged or clogged. He want $1000 so before I give green signal just want to make sure.

 

Had 3 gallon of gas sitting for 5 years. Without thinking put it in my 99 civic gas tank, mixed with 7 gallon of new gas. Since then car is stalling and now check engine light is on. When engine warms up car stops running if rpm goes below 2000 and the engine dies. Cold engine starts.
Took it to Autozone and got misfiring codes. When car gets warmed up it dies.
What could be wrong? Where should I start?

 

you could start by bumping ur other thread that you started about this problem instead of starting a new 1.

 

you probably have lots of condensation/water inside of the old gasoline which is why this is happening. All you can really do is either drain the tank or drive the car at slightly higher revs until you burn off the fuel. If you can get a code reader, find the code and see what it says, prolly will say something like lean-fuel mixture trim some other such crap.

 

Went to Autozon and got these codes
p0303, P0304, P0300, P1399
These codes are for misfire

 

i don't know if it's too late, but you could try adding Sta-Bil. I'm not sure how or if it will work in this case.

 

Drain the gas and refill it with fresh gas.


^^^ I would say it's too late for that.

 

Old gas is already used up. Now there is fresh gas in the take.

 

You said you mixed it, how do you know it's used up? Unless you mean you ran the tank threw.

If the problem continues maybe try checking the plugs?

 

Yes I ran the tank threw.
I pulled up all 4 spark plugs they looks ok.

 

huh. When is the last time the car has seen a tune up? Have ran any fuel system cleaner or something of that sort threw it?

 

Get water out and put it in your gas tank or drop you tank and try to run new gas through

 

also try changing your fuel filter first run some HEET or some crap trough your car seafoam it even than change the fuel filter and than get back to us

 

Drain it and just run it in a lawnmower or a flamethrower. Don't throw too many additives in, but the HEET is a good idea, it'll absorb moisture. Over time, the volatiles evaporate off from gasoline and it leaves behind a varnishy buildup. Next fresh tank, definitely run some good fuel system cleaner through, like Chevron Techron.