Monday, March 21, 2011
2004 Saturn Vue 3.5L
Anyway back to the task at hand. The complaint is that the car would run then stall and have issues restarting. After talking to Mr. D he tells me that he had it running in the shop and it ran rough for a second and then stalled after a period of time. Trying to restart the vehicle it would start and stall immediately. "Like a theft issue Johnny". After letting it sit it would restart and then the whole cycle would repeat itself.
Doing a quick visual it is apparent that this vehicle took a hit in the left front and was "repaired". I will leave repaired in quotations. I hope the body shop saved this guy his deductible at least.
I start the vehicle and it runs well with a MIL lamp on. So lets pull some codes. I pull a P0300 (Random Misfire), P0301(Cyl. 1 misfire), P0302 (Cyl. 2 misfire), P0303 (Cyl. 3 misfire), P0304 (Cyl. 4 misfire), P0305 (Cyl. 5 misfire), and a you guessed it P0306 (Cyl. 6 misfire). Geez, what is going on here. All sorts of thoughts run through my head with these codes and the complaint. Do I have a fuel pump pressure problem, possibly a power issue to the COP (Coil on plug) units, or something else affecting all the cylinders with 122k anything is possible. So, I hook up the scanner and set it up to read map kpa, rpm, and short term fuel trims on both banks. Now I wait and observe the scan data and how the engine is running. Map kpa is smooth amd fuel trims are well within reason. As myself and Mr. D are leaning over the car commenting on the "fantastic" body work, I say to Mr. D that I bet this thing stalls when the cooling fans come on. No sooner than I say that the cooling fans come on and the car runs rough and stalls. Trying to restart nets me the start and stall issue. So, I disconnect the cooling fans because I already know where I am going and the car starts and stays running. Lets examine the wire schematic for the cooling fans below. By the way double click on the image to get it to be full size.