92 3.3 century rough idle

[Yung-Moose86]

Alright guys I've tried everything I can and now I'm here hoping someone might be able to guide me in the right direction.

The car only runs rough at idle, I've now noticed since the fan relay wiring has been fixed and a new relay installed it turns on as it should but draws the power of the car down alot. I've checked the harness for shorts nothing to be seen. I've changed plugs, wires, coils, cleaned old iac and changed it out for another still to no avail. It stumbles over itself. Crazy part is that there's no problem with power driving it has life and still gets up an goes just has a hard time idling. What else can I do? Could it be the alternator? Fuel injectors seem good as well. Also I have gone over every vacuum line with starting fluid and no leaks surprisingly

 

[CorvairGeek]

How many miles? The 3300 doesn't have the best idle characteristics, but has plenty of power. The first generation Multitec injectors can be troublesome too.

 

[Yung-Moose86]

How many miles? The 3300 doesn't have the best idle characteristics, but has plenty of power. The first generation Multitec injectors can be troublesome too.

108,xxx I definitely haven't heard a lot of positive things about the 3.3

 

[2007LucerneCXL]

You can check for codes and while not as good on what a OBD2 it could point to a area to troubleshoot.

From what you said with the fan you may want to check the alternator especially at idle if not operating at the correct level output it can make things unstable.

Fuel system would be the next thing to check on pressure, fuel filter, etc the old stand by of tossing in a bottle of Chevron Techron. Unless the injectors have been tested there is no way visually to know.

 

[Yung-Moose86]

You can check for codes and while not as good on what a OBD2 it could point to a area to troubleshoot.

From what you said with the fan you may want to check the alternator especially at idle if not operating at the correct level output it can make things unstable.

Fuel system would be the next thing to check on pressure, fuel filter, etc the old stand by of tossing in a bottle of Chevron Techron. Unless the injectors have been tested there is no way visually to know.

I did check for codes and it had a 26 and a 39 so typical TCC solenoid it's already unplugged shifts fine and Quad driver module probably from the TCC no other codes.

Alternator did cross my mind I'm gonna have it tested and see. After that I'll go thru fuel system probably start with the fuel filter and go from there. I'll be back to share what I find fixed or not.

I really appreciate the answers guys gave a good direction to go in and at the end of the day if this 3.3 is as good as a boat anchor I'll start my search for a 2.5 or 3.4.

 

[CorvairGeek]

The Buick 3300 is actually a very simple (MPFI, no EGR, no MAP) and very durable engine. They were cast for a counter balance shaft, but GM chose not to install it, unlike its bigger brother, the 3800.
Besides checking the alternator, which the CS130 series alternator is unreliable IMHO, check and see if you have liquid in the vacuum line of the fuel pressure regulator. The diaphragm ruptures and fuel can be drawn through it.

 

[Yung-Moose86]

The Buick 3300 is actually a very simple (MPFI, no EGR, no MAP) and very durable engine. They were cast for a counter balance shaft, but GM chose not to install it, unlike its bigger brother, the 3800.
Besides checking the alternator, which the CS130 series alternator is unreliable IMHO, check and see if you have liquid in the vacuum line of the fuel pressure regulator. The diaphragm ruptures and fuel can be drawn through it.

I give a look to that diaphragm today when I get home the alternator definitely isn't the main cause of problems but I definitely feel like it's not working 100% thank you again for the input I'll get back to you with results