Long Crank + Gas Smells From Exhaust

ericv1984

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The car broke down about a month ago, had a misfire and would barely run, pulled the codes but I forgot which ones they were. Replaced the coil packs, spark plug boots, spark plugs, and fuel pump. The car ran but still like crap, broke down again and pulled the codes again but again I forget which ones, so I replaced the camshaft position sensor, throttle position sensor, and MAP sensor. Car ran again but would have a long crank plus a gas smell and would occasionally stall when the engine was hot. When I replaced the three sensors, I was going to replace the crankshaft position sensor but since you have to remove the starter to remove the sensor, I left it alone for now. Do you think maybe the crankshaft position sensor should be replaced? Also, I have a brand new fuel pump assembly thinking maybe something went wrong with the one I had installed.

I've only had the car for a few months. Here's a list of things I've replaced since we bought it.....

New camshaft position sensor
New throttle position sensor
New MAP sensor
New spark plugs, NGK platinum
New coil packs
New spark plug boots
New air filter
New fuel filter
New fuel pump
New idle air control valve
Oil change was done about 1,500 miles ago with Castrol GTX High Mileage part synthetic

The car also has 192,xxx miles. It's a 1998 Pontiac Sunfire SE 2.4L 4-speed automatic. The only code that comes up is a P0171 for the upstream oxygen sensor. Maybe the oxygen sensor is causing the gas smell, but I don't see how that could cause a long crank?
 
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Lean codes mean you're not getting fuel burnt in that cylinder, either because you're not getting fuel not it's not getting burnt. Third possibility is that the 02 sensor is not getting read correctly. I'd pursue that avenue first.
 
Coolant temp sensor, or pull the vacuum line from the fuel pressure regulator. If there is gas present, replace the regulator
 
Coolant temp sensor, or pull the vacuum line from the fuel pressure regulator. If there is gas present, replace the regulator

I already replaced the regulator, even though there was no gas coming from the vacuum line. I forgot to mention that.

One of the symptoms of a bad coolant temp. sensor is black smoke, which my car does not do. And it says ...

"a malfunctioning temperature sensor will often send incorrect information to the vehicle's on-board computer. As a result, when the vehicle reaches a normal operating speed the sensor may relay an incorrect signal to the computer that the engine is overheating resulting in engine shutdown. The vehicle will not be able to start again until the engine has completely cooled and will need to have the sensor replaced in order to prevent the recurrence of the problem."

Which is also not the case. When it stalls, it only happens when I turn the car off with the engine hot then come back to turn the car on. It then stalls, I crank the engine again and it sputters and acts like it wants to stall. I rev the car in park and the cars drives fine after that.
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For a p0171 code the number one thing to look at is the MAF sensor. I'd recommend cleaning it, and replace if that doesn't help. Also, go over all vacuum lines visually and look for cracks, a vacuum leak will also throw this code. One other possible cause, but it is way down the list is a faulty upstream O2 sensor. With your car having 192k on the clock,and not being sure if it has ever been replaced, it might not hurt to go ahead and replace it too.
 
For a p0171 code the number one thing to look at is the MAF sensor. I'd recommend cleaning it, and replace if that doesn't help. Also, go over all vacuum lines visually and look for cracks, a vacuum leak will also throw this code. One other possible cause, but it is way down the list is a faulty upstream O2 sensor. With your car having 192k on the clock,and not being sure if it has ever been replaced, it might not hurt to go ahead and replace it too.

I bought a upstream O2 sensor tonight but not looking forward to replacing it. Only cause original sensors can be really stuck in there. Also, my car doesn't have a MAF sensor and I looked at the vacuum lines under the hood about a month ago when I had my misfire, and they all looked good.

I was thinking maybe the O2 sensor could be causing the gas smell, but very unlikely for the long crank since I don't see how a O2 sensor can cause that, and the crankshaft sensor for the long crank. Which I have a spare crankshaft sensor but also not looking forward to installing. I'll install the O2 sensor first then, and see if that changes anything. If that doesn't help then I'll look at the fuel filter to see if it's dirty or clogged. If that doesn't help then I have an automotive stethoscope on order, as soon as that gets here I'll test the fuel injectors.
 
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Ah, you're right. I missed that you have a 2.4 and it doesn't have a MAF sensor. I wish you luck with your repair. Let us know how it turns out.
 
Ah, you're right. I missed that you have a 2.4 and it doesn't have a MAF sensor. I wish you luck with your repair. Let us know how it turns out.

Thanks, will do.
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Was going to replace the oxygen sensor today, but it's raining outside so don't know when I'm going to get to it.

But, I should also mention that after I replaced those 3 sensors and got the car running, on the way home on the freeway, the car started sputtering going up the slightest of hills but then would drive fine again when it got on a flat surface. And at that time, the fuel tank was half full. It hasn't happened again since then, probably because I don't let the tank get below the 5/8 mark just in case something is wrong.

I went out today and had to go up a few pretty steep hills, and the car went up fine, but the tank was just above the 3/4 mark. But going up the hill, it didn't get up to speed as quick as it usually does. Was going about 70 and would very slowly go higher. Is this part normal? Cause I know some older cars have a difficult time going up steep hills as oppose to newer cars.
 
So you are saying the ease of going up a hill is effected by the gas tank level? If so, I would be curious what your fuel pressure is and if you have a problem with the evaporative control system causing the fuel smelll. You did trace all the fuel lines to make sure you dont have a leak?
 
So you are saying the ease of going up a hill is effected by the gas tank level? If so, I would be curious what your fuel pressure is and if you have a problem with the evaporative control system causing the fuel smelll. You did trace all the fuel lines to make sure you dont have a leak?

Not exactly. I only looked under the car to see if I could see any leaks.

What be more likely to go first, the charcoal canister or the purge solenoid?
 
Barring really unusual circumstances, the purge solenoid. Theoretically, a purge canister should never go bad.
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Been putting this off cause didn't really feel like working on the car but recently I bought a purge solenoid and a purge valve. Just replaced the purge valve, still the same. So next step is replacing the solenoid. If that doesn't work then I'm gonna put a new fuel pump assembly in, since I have a new one sitting in my trunk.
 
Correction, the new purge valve got rid of the gas smell from the exhaust.
 
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