Engine Performance problem
2004 Mazda 6 4 cyl Front Wheel Drive Automatic 85000 miles
Engine stalls at unpredictable times while at idle in drive and during acceleration. OEM spark plugs and wires recently installed. Mazda dealer in NC has looked at it, connected computer to it, no solution. No check engine light shows up, so Dealer cannot troubleshoot without code from computer in order to claim repairs on extended warranty. Daughter is driving the car in another state, so I can`t get my hands on it. Any clues?
I need some more specifics on your vehicle to better assist you. Is your vehicle a 6 I or 6 S.
Since you can not get your hands on it. We need her or someone there to do a couple of things so we can narrow it down. We need to figure out if it is electrical or fuel related. When this happens, we need to pull a plug wire off of the spark plug and insert something into the end of it and have someone try to start the car and have the metal object really close to a piece of metal on the engine and see if you are getting a good strong popping blue spark. Don't have your hands on any part of the metal! If there is no spark, then it is electrical. If you are getting good spark then you need to get a fuel pressure check on the fuel pump to ensure it is putting out okay.
December, 7, 2008 AT 12:36 AM
Thank you for the donation.
When no codes can be retrieved, it usually is not easy to diagnose.
First we need to know if it is power or fuel supply that is causing the problem.
If it is power supply, it ususlly would cut off abruptly.
Fuel fault would usually bog with power losses before it cuts off.
Was it easy to restart when it stalled?
Were the dash indictor lights showing when it stalled?
What is the idling speed?
Any hesitation or power loss during normal driving or prior to it happening?
December, 7, 2008 AT 2:36 PM
Answer to questions: 1) Easy to restart - yes.
2) dash lights on when stalled - yes, all.
3) Idling speed - appeared normal at first, then hesitation and stall.
4) Hesitation or power loss while driving - yes, it has hesitated, run rough just before stall with no acceleration such as pulling in to a parking lot from the main road or siiting still in drive. It does not apppear to be happening while acceleration or manual control of fuel while driving, although the latter did happen once on a turn.
This is a 4 door sedan, stock.
To me it sounds like a fuel problem.
December, 8, 2008 AT 2:49 AM
I scanned through the Mazda Technical Service Bulletins and there is one article on a frozen main relay. It seems mpisture can enter the relay and intermittently causes the relay to fail resulting in engine stopping.
As the symptoms described seems a likely relay fault, I would suggest replacing it. It is recommended to replace and relocate the main relay and fuel pump relay with the modified kit for 2003 to 2005 models.