willhenderson04

Hi all, I'm getting pretty desperate with my car. It's been hesitating for a few months and running rich with a few backfires. Recently it would stall at red lights and bog down on take off, until it got to the point where it couldn't be driven because it bogged down so much. Ran the codes on my ecu and it was telling me coolant temp sensor. I replaced the coolant temp sensor and it ran great for about 1 minute then died again and couldn't get it going, and to make matters worse, the diagnostic screw on the ecu is just spinning. Please help! Don't think it is the aav because when i got it running it idled pretty high and i had to adjust it to make it lower. it was idling beautifully at 1000 rpms and then like someone flipped a switch it went back to running really rich.

Amiry366

I am suffering the same problem. When it is cold, it runs pretty good. When it gets warm, it starts being an ***. Our problem is definitely related to the sensors that tell the ecu that the engine is hot or cold. The reason for running good at first is because when you start the car when it is cold, the ecu is running in open loop. In other words, ecu is running on the programmed map. It just calculates the amount of air and injects fuel. However, when the car gets warm, ecu gets off of the open loop and goes to close loop and starts to run the engine based on the sensor readings (o2, exhaust gas temp, coolant temp... Etc.). I had a full tank of gas two days ago and now I'm at middle. I haven't even drove the car. Its running pretty rich. What i would suggest to do is to unplug o2 sensors. Both of them. Because malfunctioning ones could tend to send the wrong signal to the ecu and make the ecu think and it is running lean; therefore, the computer adds more and more fuel until the engine gets flooded and wont start. Unpluging o2 connectors should enable the ecu to pump the correct a mount of fuel (because it would force it to run from the programmed afr map). When you unplugged the connectors, hop in and drive the car around the block and see if the problem has solved. If it has, then congrats. You need new o2 sensors. Sometimes you can also take out o2 sensors and clean them reall good with parts cleaner, as running rich would cause carbon deposits on o2 sensors hence not functioning correctly and make the engine think it is running rich. Hope it helps