3.4 problem

[CAMAROWIDBASS]

I was driving allong mindind my business when i hear some unusual noises coming from under the car. I immediately noticed my exhaust pitch changed to a more ricey tone.

A fer seconds after that the car started shaking noticably and it was hard to accelerate. I get to a red light and the car is running pretty rough.

When ever i give it gas it struggles to get up to speed and shakes and vibrates but as soon as i let off the gas the ride is nice and smooth.

Im thinking bad cat or muffler. Any other input?

[97SILVERBIRD]

Could be plug wires, plugs , fuel filter, or fuel pump
good luck

[CAMAROWIDBASS]

i replaces the fuel filter today and no luck, plugs and wires are less than a yr old but ill still check them.

[3.4 slow to go]

check the cat.when the one on my blazer cracked, I couldn't even tow a 2 wheel car dolly up hill.

[shenanigans]

thats sounds definite cat to me...

still unhookable? if so unhook it run an open y pipe and see if the car runs different.

when the cat goes, the pieces float around in the cat, at cruising speed they are ok, but as soon as you gun it, exhaust pressure increases picks up the junks and tries to force them out into the rest of the pipe but they don't make it through and it the piece comes up sidewasy it glogs it...

kinda like the someone putting a potatoe in your tail pipe.


If its not that might be fuel pressure/pump related. BUt the exhaust tone change is a dead giveaway.

[CAMAROWIDBASS]

yea like i said the exhaust tone changed a LOT it sounds very ricey almost like if i have a fart pipe.

Can a muffler clog?

[viper98885]

Sounds more like and ignition problem to me. If you are firing on 6 cylinders and you know the tone and then you drop one, if not two cylinders, you will definitely tell a difference. Kind of like the difference in tones between a Honda and our cars. If one coil went out (which fires 2 cylinders), you would get that tone and a VERY poor performance.

My advice is to check into the ignition first before dealing with the cat.

[CAMAROWIDBASS]

any way to test an ignition coil?

Also i have an ohm meter whats the best way to test the resistance on my wires? what range should they be in?

[ July 01, 2005, 08:28 AM: Message edited by: CAMAROWIDBASS ]

[camaroman1181]

you can test an ignition coil by taking an ohm meter across the top two terminals.. thats the secondary check.. the primary check is bout the same... you test the ohms across the two connections on the bottom of the coil. this test is harder though cause those slots are very narrow and its hard to get the probes to make contact. if you try to use somethign else as a probe extension, you could throw off the resistance reading if you dont zero the reading correctly. I forget the appropriate readings for each test but if you call up autozone, they can tell ya what the appropriate readings for each test are. ask for the specs for coil C849...
As far as testing the wires, there really is no certain range for the wires to be in. Depending on what type of wires you have on there now, the values will vary greatly. What I usually do is test teh wires shortest to longest (or inverse) and make sure that the resistances change in accordance to the length of the wire. If you have a wire in the middle that has 2x the resistance of your longest wire, i would say you have a problem.
good luck and hope that helps some..

[94Redbird]

I recently tested my coils and the easiest way to test the primary is leave the coil sitting on the terminals but just raise it up enough to get the probe underneath and then you can measure the resistance across the terminals. You can also unplug the connectors to the ICM module and test them through those if you have a wiring diagram to know which pins are which... but you may pick up some extra resitance that way.

[shenanigans]

does the car idle rough or smoothly?

that woudl be a semi tell tale sign if its a cylinder is missing, vs a CAT or fuel pressure.

[CAMAROWIDBASS]

the car idles noticabely rougher than normal,
during idle its not that obvious.

My dad drove it and he said that to him it felt like the car ran fine.

[pontiac nino]

Does it idle rough right on start up? Or does it take awhile to start idling rough? Kinda sounds like it's running rich. Somehow I think it's the O2 sensors.