OT: We have any car mechanics out there?

[dsm]

Cygnusia,

Seems like the best bets based on feedback thus should include ...

- O2 Sensors
- Fuel pump or Fuel filter
- Mixture control

Good luck with it.

DSM

PS

Just thinking again about what typically causes engine to die out when full throttle is activated ...
- too little fuel making its way to the injectors
- too much fuel flooding the spark

D

[ifrimmel]

If the engine was missing you wouldn't be having these problems tho.

Right, but wouldn't that be a more significant issue?

Muffy

Substantially ... and somewhat catastrophic .. alternative means of propulsion would need to be secured.

[JStaggie]

Could be a failing fuel pump.

[Cygnusia]

The fuel filter was replaced during the tune-up. I've eyeballed that one myself, it's brand new, no dirt or sludge or crap on it at all.

The fuel pump will probably have to be pulled out at some point, since the fuel sender unit is incorporated into the whole assembly. Thankfully, it's one of those "under the back seat" jobs, so no dropping the fuel tank for me.

I would take it to Autozone, but I don't trust the car to get around the block without dying, let alone on the main road through town. It died on the way home from the mechanic with a big rig behind me... definitely a heart-pounding moment! That's why I'm going to simply rent their code reader and bring it back when done.

It COULD be the O2 sensor hooked into the cat... I distinctly remember my mechanic saying that it was misfiring when it was hooked up but would run (albeit not nearly as efficiently) without it. Is there any way to clean a sensor instead of replacing it? These suckers run over $100 apiece and I'm on a budget... still upset that I ended up with another clunker I have to put back together...

[allen476]

There could be several things that it could be. Though the 3 things you need to check first is

1) Spark. Do you have spark? Autozone has spark testers and the cheapest one is around $9. If you dont want to go that route, take an old spark plug and place it very near a ground (engine block). DO NOT HOLD ON TO IT. Have a helper turn over the ignition and check for color of spark. If it is a blue color, you are OK. If it is orange/red color, you have bad spark.

2) Fuel. Is the engine getting fuel? First do you hear a whirring or buzzing sound for about 2-3 seconds when you turn the ignition on? If not then you more than likely have a bad fuel pump. Next go to Autozone and rent a fuel pressure tester and test according to the directions. You will need to know the fuel pressure range from a service manual as well. Low pressure could indicate a clogged fuel filter or a pump that is going bad.

3) Air. No hooking up your CPAP to the air intake won't make it feel better after a few days. This area is the most overlooked as it is as vital as the other two. Since you already have stated that you had the car tuned up, then the likely culprit in this chain is the idle air control valve. It makes it hard to start in the cold and run rough for awhile.

You could take it to the AZ nearest you and have them scan for any problems. There are too many variables to say what it is exactly.

Allen

[Wulfman]

Check for any cracked/broken/leaking vacuum line hoses (if it happens to have those)?


Den

[Gerryk]

The fuel filter was replaced during the tune-up. I've eyeballed that one myself, it's brand new, no dirt or sludge or crap on it at all.

The fuel pump will probably have to be pulled out at some point, since the fuel sender unit is incorporated into the whole assembly. Thankfully, it's one of those "under the back seat" jobs, so no dropping the fuel tank for me.

I would take it to Autozone, but I don't trust the car to get around the block without dying, let alone on the main road through town. It died on the way home from the mechanic with a big rig behind me... definitely a heart-pounding moment! That's why I'm going to simply rent their code reader and bring it back when done.

It COULD be the O2 sensor hooked into the cat... I distinctly remember my mechanic saying that it was misfiring when it was hooked up but would run (albeit not nearly as efficiently) without it. Is there any way to clean a sensor instead of replacing it? These suckers run over $100 apiece and I'm on a budget... still upset that I ended up with another clunker I have to put back together...

Many vehicles have more than one fuel filter. Did you say the fuel guage stopped working about the same time this problem came up? I know some manufacturers have what's called a sock on the fuel pick up tube. They are supposed to be self cleaning, IE the junk falls off and back into the thank. The sock just keeps big junk from getting into and plugging the fuel line or filter. Some of those fuel pickup tubes move with the float so they are never all the way at the top or the bottom and they can get stuck. Hence your vehicle could be starving for fuel. Also check the air filter and air filter inlet. Small animals can make temporary homes in these types of things over night and cause major problems.
Sometimes with the new computerized cars the mechanics forget to check the simple things. Do you have a full tank of fresh fuel?

[Rebecca R]

Wild Guess:
Did you check the fuses? If there is a fuse for the fuel pump relay, perhaps also affects the fuel tank?

[dsm]

Doesn't it just make you smile

Here we are trying to help an automobile get its respiration right. Poor thing may have an O2 imbalance or it may be hyperventilating.
The chemoreceptors in the exhaust may be failing to detect the correct PaCO2 balance -

Hmmmm while thinking along the above lines just had another idea that may be on, or, way off target but worth the thought ...

Maybe the cat(s) are flat !!!

If either or the only catalytic converter has collapsed it may be blocking exhaust flow & stuffing up the onboard computer.
Again I had a problem like this - a cat collapse caused excessive sump pressure which confused the auto gearbox which
has a pressure modulator that relies on sump pressure to provide clues as to when it is ok to change gears.

Just another idea - check the cat(s).

DSM

#2 - my car had 2 cats & one had dissolved while the other collapsed & blocked the exhaust in one side of the dual bank
of six cylinders (a V12). The car ran very poorly & several mechanics failed to wake up to the fact that the engine was
on half power. So a single engine with only one collapsed cat would run very sickly if the bits of the cat were blocking
the exhaust flow.

[-SWS]

Back on track...

It's idling rough and sputters badly when you try to give it gas. It will lose power and die when up to speed, or just sitting idly.

Did you check the air in the tires and the radio? Also, has anybody thought to suggest that the central ASV unit might be dead?

Good luck.

[Cygnusia]

Well, it's definitely getting spark and fuel. It actually turns over quite easy, hardly has to chug at all to start up. It's once it's running that it starts showing off its issues. A very rough idle, and every time you press the gas it's just chugs and shakes. If it can get up to 2000 RPM it smooths out (if it doesn't choke completely and die) but at some point it will just lose all power and die.

It also does have a fuel filter inside the tank like you described. The entire tank WAS actually replaced (thankfully not on my dime) and the fuel gauge issue started then, according to the previous owner.

[Cygnusia]

It only has one cat and it's fine. It's actually one of the first things my mechanic wanted to check. He said the car was in really bad shape, tune-up wise, and he wanted to make sure the cat had survived all the punishment the vehicle took.

The fuses LOOK fine... but I need to get a tester and a combo box of fuses anyway, never know when one might go out. I also should get the two relay blocks checked (one does involve the fuel pump) while I'm out at Autozone.

[Rebecca R]

Back on track...

It's idling rough and sputters badly when you try to give it gas. It will lose power and die when up to speed, or just sitting idly.

Did you check the air in the tires and the radio? Also, has anybody thought to suggest that the central ASV unit might be dead?

Good luck.

You forgot to ask the color of the car, definitely a contributing factor.

[-SWS]

In addition to those other good suggestions, I'd suggest visually inspecting your vacuum lines to make sure one's not disconnected...

If you see any brittle or slightly cracked lines, you can liberally spray those with water----while applying target RPM to troubleshoot any vacuum leaks. If the rough-running symptom suddenly disappears with liberal water sprayed, then that line will have to be replaced.

But intuitively I bet Muffy just knows it's gonna be the central ASV unit....

P.S. What color is that car anyway? It's clearly a contributing factor.

[dsm]

By the way
ASV is as every self respecting car mechanic knows, stands for

Automobile Status Viewer

If that is dead you'll never know what is wrong
A state of the art ASV is at the heart of all good vehicle air & fuel flow

DSM