"I'm mainly curious if there's anybody out there who experienced these similar symptoms and what was the problem on yours?"

"Sorry, this turned out alot longer that I expected, I may try to re-edit it shorter, I always do this".
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My dad and I have been troubleshooting the engine off and on for awhile now. If you have any ideas of what it could be, please let us know.

Let me begin with the strange symtoms:
It began about a year ago. It would run great for the first 30 minutes or so. But then say coming back from Walmart it would not run right; start skipping/missing sounding weird with rough idle. Almost like it's missing on a cylinder.

My dad found some spark plug wires sparking against each other, and we thought that was the problem at 1st. -- We replaced the wires but that wasn't it. It actually did help at the time that day, but maybe the problem got worse.

This pattern would continue for months. It would run fine for first 30 minutes or so if you let car sit for say couple days. Then go bad.

Minor symptoms car always had even when running "fine" years before the bad symptoms:
A couple of other sypmtoms the car always had since I first bought it, and these are MINOR symptoms, but maybe it might be related is that the car did not run good when outside temperature got below 60 degrees. It would throw a check engine light, hesitate, and not run real strong. It was the 1st engine i had to not like real cold air.(most engines run stronger w/cold air)
Also and this is somewhat strange, but say you have been driving for awhile, so engine is heated up. If you kill the engine, it will not restart unless you let it sit for like 5 minutes or so.

Ok back to major symptoms:
So for months car could run great for 1st 30 minutes, but say on a drive, almost if you hit a bump in the road then the engine could start acting retarded. And maybe hit another bump,and it go back to running good again. So at that time I thought something is loose?

But our thinking was ok, maybe something is heating up and once it gets hot, it start malfunctioning.

That led us to replace the "COIL"(whatever that $100 thing that drops down into the engine near that cap where spark plug wires go, and if water gets in there messes it up, we've replaced this a few times, and now have a piece of cardboard to cover it so when it rains water doesnt go in there to cuase it to go bad(this worked for many years). Well we replaced this, as well as the Mass Air Flow(a couple times), and that wasn't it.

Per my dad, we replaced the PLUGS, That did not fix it.
We checked the FUEL, fuel seems ok.

He recently checked spark, and that seemed ok.

The last we messed with it in colder weather, and could not even get the engine to start.

But last he troubleshooted the spark in warmer weather and it did crank up at least. But ran "bad" like it did before. And now it doesn't even run "good" for the 1st 30 minutes anymore.

What we are going to try next:
We are going to try replacing the coolant temperature sensor, even though its not throwing a check engine light, who knows maybe its bad telling computer wrong information. And this sensor did cause my 94 saturn to run bad, so who knows maybe we'll get lucky but doubtful.

I went to autozone.com and might look at replacing a "electronic spark control module", and maybe the "ignition control module"(not sure if we did this one already).

We did replace the cap, rotor thingy.

Oh, and as we replaced these tune-up items, the symptoms have got worse. It now does not drive "good" for the 1st 30 minutes any more.

We might replace the COIL again thinking maybe we got a faulty one.

We might try the "intake air temperator sensor" too.

We replaced fuel filter.

I'm mainly curious if there's anybody out there who experienced these similar symptoms and what was the problem on yours?

Thanks and I appreciate your time and any feedback.

 

My problem ended up being Faulty Injectors.

 

could be a worn-out fuel pump.

 

it was the injectors. if it wasnt we was going to do the
fuel pump next. thanks tho.

 

glad you fixed it. Looks like you had a ton of help on here lol.

 

Thanks man. It's been about 1.5 yrs since it ran good.
Not sure if you was being sarcastic. I started 2 threads on this "general engine" Forum and yeah, I didn't get many responses.. BUt then I started 2 threads in the "TPI" forum and got much better help there.

 

Yes I was being sarcastic. I dunno what happened on here but sense the weather has gotten nice no one is on any more. I'm only on late at night now because I cant stand to sit in front of the computer on a nice day.