CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Help!

I’m a single mom and really dependent on my car for my job and my kids… I have a 1995 Chevy Camaro 6-cylinder, and I am having engine problems… in the mornings, my car starts fine, but if I drive more than a few minutes and turn it off, she doesn’t want to start up again. It turns over just fine, but it sputters and refuses to stay started. After a couple of tries, I can get it going, I rev the engine, and a cloud of dark smoke (not blue and smells like gasoline) comes out. I also smell gas strongly when the engine idles after everything smooths out. Sparkplugs, fuel filter, oil, air filter, belts, hoses, all have been replaced recently, catalytic converter is only four years old, and car has 178,000 miles on it. Can anyone tell me what I may be dealing with? I’m also losing acceleration/power when I try to speed up… any ideas/suggestions would be greatly appreciated!!! :slight_smile:

Your engine is running very “rich”, meaning you’re putting excess gas into it through the injectors. The black smoke is carbon from pooorly burned gasoline.

The possible reasons for this - in the oder of liklihood- are

  1. a bad temp sensor, telling your computer that the engine is colder than its is and causing it to add more gas, (that’d be my best guess)
  2. leaky injectors allowing excess gas to be sprayed in
  3. a bad fuel pressure regulator, allowing excess pressure (very unlikely)

That black smoke and the unburned gas are also going into your cat converter and can damage it. You may not want to procrastinate on getting it fixed.

Yeah I have to agree. Your engine is getting flooded with gas after shutting it down would be my guess. So leaking injector(s) or fuel pressure regulator would be a good guess but you’re going to have to have a diagnosis done on it.

Thank you! Obviously temp sensor is going to be the cheapest fix, and a bad injector was my guess since the car is 17 years old, but between myself and the last owner, this car has been babied and primped for the last 10 years. I just replaced the water pump, power steering pump, serpentine belt, coolant temp sensor, next is the blower motor for the A/C (have it ready, but it’s in a difficult spot to access, went out over the summer here).

Looks like you already replaced the temp sensor then. Injectors are good for about 400,000 miles but they can go bad. You can remove the hose on the fuel pressure regulator (round device on the fuel rail) and see if there is gas in there. If so it is bad. Its just a vacume diaphram and can wear out over time.

I will pass on the info to my helper that’s been assisting me with my repairs, thanks so much for the help!

I will pass on the info to my helper that’s been assisting me with my repairs, thanks so much for the help!

Your fuel injectors could be leaking, after sitting overnight the excess fuel is a non factor. Restarting the raw fuel is in your cylinder causing your problems. This will foul your plugs and catalytic converter so the sooner addressed the better off you will be. You may get lucky with seafoam or techron treatment for the gas, and just cause your gas filter may be failing check to see if it is overdue for maintenance, as impurities not filtered out can cause problems. A nice long drive at highway speed will help clean the plugs and burn any gas out of the oil.

@ningirl1 since the engine’s running so badly I’ll assume the service engine soon light is on.

If so, can you post the fault codes please.

Be sure to take advantage of the car’s self-diagnosis feature. As db4690 says, have the codes (pending and current) read. If you post them here, you’ll get some good feedback. The codes often will define exactly what is wrong.

Beyond that, the only thing I can add is that if this happened soon after replacing the temp sensor,you simply may have had bad luck and got a bad one from the parts place. Either that, or the wiring or sensor connector was damaged during the interchange.

Be aware that there are sometimes more than one temp sensor in an engine. Sometimes the one that is used to display the coolant temp on the dashboard is different than the one the ECM uses for calculating fuel injection parameters.

The filter was replaced in October, there is less than 1500 miles on it since I haven’t gone on any trips longer than 50 miles. Check engine light flickers but goes out again, and isn’t on long enough for me to scan a code off of it.

Good thing I got this car for free, I guess… lol

The car starts up fine in the mornings, or in the evening when I’m ready to leave work. The problem occurs after I’ve driven it for more than 10 minutes and the car is warmed up. No issues on the highway other than the boggy acceleration.

Hopefully you saw previous response.

If it’s any more motivation, your fuel economy will be down quite a bit until this is fixed.

Check to see if any fault codes are stored in the history.

@ningirl1 Do me a favor. Pop the hood and look at the emissions sticker. Does it say OBD 2 compliant anywhere?
Is there a D-shaped 16-pin data link connector in the cab on the lower left side?
If your car is OBD 2 compliant (some 1994 and 1995 cars were), that could make it easier to diagnose.