2005 Buick Rendezvous AWD 3.4L stalling, running rich

[Guest]

Problem with my 2003 Buick Rendezvous
service engine soon
question = I just bought a 2003 Buick Rendezvous 2 weeks ago. It has 78800 miles on
it and started acting funny today. At idle and at very low speeds (when we're first taking
off, backing up or slowing down) the car starts to sputter/jump and feels like it wants to
cut off. At normal speeds, the car runs perfectly fine. Any ideas?
I will be more than happy to make a donation when I get paid on Friday! Please help if
you can. I just spent $8200 buying this car from an individual and I am so upset!
Thank you so much for you time

[butchkaz]

Burned spark plug wire or bad spark plug is the most common cause of a misfire on this vehicle.

[nealdmu]

2005 Buick Rendezvous AWD 3.4L Car started stalling at low idle We got Codes Po300; replaced spark plugs and Ignition wires; problem still there; plugs black with fuel, before and after replacement; Code 132 appeared; replaced upstream O2 sensor; still having same problem

[ProTech]

If the plugs are black with fuel, you're obviously running way too rich. This is either due to too much fuel or too little air. Make sure the air filter is not clogged and that there is no debris on the mass air flow screen. If the vehicle is actually misfiring and you have new plugs and wires installed, then you'd be looking at injectors or possibly coils breaking down. If it's missing on all cylinders, it probably isn't all six injectors, or all three coils going bad, it has to be something in common. That could be something like a clogged catalytic converter causing excessive backpressure and misfires. This will usually foul out the plugs if bad enough. You didn't mention a problem getting up to speed, which is usually a symptom of a badly clogged catalytic converter. The other possibility is a leaking fuel pressure regulator. This is far more common and if the diaphragm is ruptured, you'd be dumping raw fuel right down the intake which can also cause the problems you're having. To check that, you can remove the vacuum line from the regulator and see if any fuel leaks out. This is best done when the engine is hot (careful of fuel spillage and fires). Also, faulty oxygen sensors can cause the computer to dump fuel if they are not reading correctly. I would recommend getting it scanned again, and probably taking a look at the live data on the scanner to see if all of the sensors are within range.

[Jethro280]

95 buick dies occasionally under deceleration, starts right up. Tried crank sensor icm and coils. Strange thing is at battery i have 14 volts on scantool i only show 12.2-12.6 volts

[carriedi]

a common cause for dies on decel is a dirty throttle body. The sides of the throttle plate build up deposits in the throttle body abd when you let off the gas you don't have the minimum air flow to keep the engine running before the IAC can adjust for it. Clean the throttle body and see if that takes care of the problem.

As for the voltage reading, you should verify the readings. It is possible that the computer may have a different voltage from battery voltage from bad connections somewhere between the battery and the computer. Corrosion in a connector of at a ground bolt can cause resistance dropping the voltage. So, check for good power and grounds at the ECM