Loss of power...fuel problem?

Symptoms:


When I drive for over 1/2 an hour in the city (under 40mph) about the time my car warms up to about 220 my car starts running ruff like its missing real bad.

When shifting to D or R from P the engine clunks pretty bad and makes the car shake a little. (only after driving in the city for a while)


Driving on the freeway at 70+ I can cruise alright. But I have no power and cannot accelerate fast. I can hardly accelerate above 2500 RPMs if that. If I come to a hill or want to pass and need a little more muscle its almost like the rev limiter is limiting my car and I can't get the needed power. My car looses lots of momentum going up hills, i can here the engine revving and then being cut off, revving again and being cut off again in quick succession.
When shifting (it is an automatic) it was having trouble. It would have a few hiccups before shifting unless I stepped on the gas.



What I have done:


I've cleared my Service Engine Soon light several times. It always says "Cylindar 1 Misfire"

The light came on when just sitting at a stop light about 5-15 minutes after clearing it. (3+ times)
The light DID not come on, on 8 hours of highway driving while experiencing the no power issue.


I replaced the spark plugs.
I replaced the ignition coils (all three.)
I replaced the spark plug wires.
8 months ago I had the fuel injectors taken out and cleaned.

I drove for about 2 years in Mexico...using the gas there which isn't as clean as the stuff in the states.


5 years ago I replaced the catalytic converter. After a wreck it failed.
The engine constantly is shaking a little bit. Kind of an uneven shake.

If I unplug any of the spark plugs the engine really shakes bad!
If I give it lots of gas the shake disappears mostly.


I added fuel injector cleaner 1/4 of a tank ago. (This isn't enough time to not a change, I'll update on this once I have gone though 2 tanks.)





What does this sound like and how can I go about testing to determine what it is?


Clogged catalytic converter? - Testing: disconnect it from the engine and drive for a bit.
Clogged fuel injector(s)?
Bad fuel pump?
Bad fuel filter? (engine being starved?) Testing: take off and examine?
Something else? I have no idea!!!



My Car:

2002
Grand Am
3.4L


Any ideas? Or need more info?

Just found this http://forums.pelicanparts.com/porsche-911-technical-forum/347499-these-symptoms-clogged-fuel-injectors.html and the problem seems similar.

1. but didn't you already replaced it with a new cat?
2. didn't you removed & cleaned them already?
3. you'll need to attatch a fuel pressure gauge to do that; do #4 first since it's easier
4. can't really examine a fuel filter without cutting it apart; just replace it...

did the check engine came back again & what were the trouble codes? maybe something else is wrong, forcing the car's computer to go into "limp mode"?!?

also, did you check the transmission fluid/condition? maybe the trans is slipping at high speeds?

engine and transmission mounts are good or torn?

grounds and battery in good condition?

vac hoses are not torn?

1. but didn't you already replaced it with a new cat?
2. didn't you removed & cleaned them already?
3. you'll need to attatch a fuel pressure gauge to do that; do #4 first since it's easier
4. can't really examine a fuel filter without cutting it apart; just replace it...

did the check engine came back again & what were the trouble codes? maybe something else is wrong, forcing the car's computer to go into "limp mode"?!?

also, did you check the transmission fluid/condition? maybe the trans is slipping at high speeds?

engine and transmission mounts are good or torn?

grounds and battery in good condition?

vac hoses are not torn?

Check Engine light always comes back on reporting the same thing, misfire in 1.
I replaced the transmission fluid about a month ago. (it was doing this before then.)
The engine mounts are cracked and not in the best shape but definitely NOT the cause for the big bang when changing gears....technically yes, but not the root cause.When the car is cool it shifts just fine.
Grounds and battery are all in good condition.
Vac hoses are.....no idea. I'll check on those. Thanks.

I guess my next step is to replace the fuel filter and check the vac hoses. I'll do that and get back with you all.

1. Fuel filter change
2. New Cat. You probably destroyed the one that is on the car due to Mexican gasoline.
3. Replace motor mounts and check trans mount.
4. Do compression test on engine. May have a burnt valve.

My guess is clogged cat. Will cause all the symptoms you indicate.

so same trouble code after you replaced the plug-wire-ignition coil...

check the #1 plug,
check the resistance of the #1 plug wire (checking for continuity when you set your meter to ohms),
swap one coil to the nearby coil to see if it's a bad coil or the ignition control module...

Also check for the PROPER sparkplugs.

Those engines are capricious on the type of spark plug that you install. Might also want to check the gap.

While you have them out, before cleaning them and doing anything, visually compare the 4. You are looking for any dissimilarity in dirt and wear on them.

Bosh for example are known to cause misfire...

I changed the fuel filter last night -- It was SO clogged up the gas in it looked like oil.

I think that the crud would settle in the filter and allow the gas to flow for a bit but would then clog up and allow only a bit of gas to pass through starving the engine.

I'm not sure the problem is 100% solved BUT I took my car out on the highway for about 20 minutes and it performed incredibly better. The real test will be upwards of 30-45 minutes.

Thanks for the help guys.