Any car experts?

[Sniper82]

Friend has a older 90 Mercury Cougar and is having issues. It first started with exhaust coming into the car somehow. He said it wasn't bad but once he lifted the hood there was some smoke. Not sure if thats what caused the problem but for some reason it starts fine and runs for a few mins then dies. He said he tried changing spark plugs and wires(why I'm not sure) but that didn't fix it. He seems to think its related to the fuel pump but I'm not sure.

Most the time he said it starts fine and runs for 3-5 mins and then dies no matter how much gas he gives it. But every now and then it cranks but won't start.

Anyone have any suggestions at all as to what it could be?

BTW is has a v6/3.8L in it.

 

[VanTheMan]

Maybe check for leaks/cracks at the exhaust manifold. If it's leaking and not providing any back pressure, that could be causing problems. That's about all I can think of right now.

 

[Dobbs]

check the catalytic converter and muffler. They tend to fill up with oil and/or degrade over time. If its blocked or full of oil the exhaust does not function properly. Just so you know, the 3.8 engine is notorious for problems from that era. Take the car to a mechanic and have it checked out because it could be anything and advice on an online computer forum isnt the best place to ask, lol.

 

[homestarmy]

Originally posted by: VanTheMan
Maybe check for leaks/cracks at the exhaust manifold. If it's leaking and not providing any back pressure, that could be causing problems. That's about all I can think of right now.

I like how you say "providing backpressure" like that is something that the car needs to run...

 

[jemcam]

Originally posted by: homestarmy

Originally posted by: VanTheMan
Maybe check for leaks/cracks at the exhaust manifold. If it's leaking and not providing any back pressure, that could be causing problems. That's about all I can think of right now.

I like how you say "providing backpressure" like that is something that the car needs to run...

Yeah, I found that pretty humorous myself.

OP, you should check the fuel filter first. Start with the cheaper items and go from there. A quck check to perform is to remove the fuel filter and blow in it. Make sure to blow in the direction of the arrow that is stamped on the filter. Compare it to the new filter.

If it hasn't been replaced recently, I'll bet that's what the problem is.

 

[Demon-Xanth]

Originally posted by: homestarmy

Originally posted by: VanTheMan
Maybe check for leaks/cracks at the exhaust manifold. If it's leaking and not providing any back pressure, that could be causing problems. That's about all I can think of right now.

I like how you say "providing backpressure" like that is something that the car needs to run...

I believe he means vacuum, and if the car doesn't have that at idle the computer tends to not know what to do and can either run it super rich or super lean depending on what sensors it believes.

 

[Paperdoc]

So it will start OK but die after 3 to 5 minutes. That sounds like a system that adjusts things as the engine warms up. For example, there is an excess oxygen sensor in many exhaust manifolds as an input to the microprocessor controlling engine fuel mixture and timing. The microprocessor "knows" what should happen as it warms up from a cold start. If the sensor is feeding it false readings that might be acceptable for a cold engine but not after warm-up, the microprocessor will be making adjustments based on bad inputs. That could shut 'er down. Then there is the Exhaust Gas Recirculation Valve that regulates how much exhaust gases are re-routed back into the intake manifold, affecting fuel mixture. And there are lots more I don't understand.

Like Dobbs said, your friend could benefit from the skills of a real mechanic, rather than us amateurs here.

 

[Toastedlightly]

o2 sensor?

 

[funboy6942]

Sounds to me the engine has had it and the "smoke/exhaust" smell is the blow by passing the rings and getting into the engine compartment. Hstart the car and remove the oil cap. You got alot of smoke coming out of there the engine is on its last leg and needs to be replaced or the car trashed.

My ol 88 Chevy Astro van had it big time but hell it had over 300K miles on it. Still started and ran but dont put the inside hood back on just right and your sucking in exhaust fumes big time.

Sure it will run fine till it warms up and all the sensors kick in and aint one going to get a good reading so it just shuts it all down. But with you saying exhaust fumes coming into the car pull out the oil plug and open the air cleaner wher the ose comes from the valve cover and I will bet you see a ton of smoke where you shouldnt see any. Abd that smoke in the air cleaner is going right back into the engigine throwing all the sensors way off killing the car.

My 2 cents and I could be way wwrong but I fell I am not. Thats a ford v6 beat to death and you shouldnt see any somoke at all coming from either of thoes two places I mentioned. Maybe on a high milage car a little puff here or there but if it is pouring out of there the rings are toast and time for a new car.

Another thing to check since it is so old and maybe looses alot of oil is check the dipstiick. SOme cars jsut being a quart over filled will run like crap or not run at all and still smke too. If it is over filled drain some and that may take care of it too.