Malibu Start and stall
Car starts and then immediately stalls (no security light) Fuel pressure is 60psi at all times. When I unplug the intake cam sensor it runs fine, don't stall. I scoped the intake sensor and noticed that it only pulls down to 700 millivolt so I thought that was a problem, I had the shop put a new intake cam sensor in and still the same problem and voltage. I got a known good waveform and it is 790 millivolt, I compared the 2 waveforms and the intake is retarded 2 deg and exhaust was 11 deg retarded compared to the known good. At the time of the capture the car stayed running for some reason. I cant see the exhaust cam being off 11 deg stalling the engine, I have seen them off quit a bit more with no stalling issues. There are no codes. Thanks..
If you unplug the phaser actuator solenoids, will it idle normally? if it’ll stay running, look at the cam position error (variation) on a scan tool to see what the PCM thinks.
I forgot to unplug the phasers. I did look at the variation and when it was running it was fluctuating about 2 deg from desired. When it wouldn't run I couldn't really get any useful data because soon as my scanner started responding it shut off
I think exhaust timing that’s 11 degrees late would be like an EGR valve stuck open and will cause an idle stall. I had a KIA that acted this way at a hot idle. It didn’t get repaired as it was a dealer‘s car and went back to auction after I discovered that the issue was internal. I theorized that there had to be an internal oil leak across one of the phaser passages that allowed some oil
Is it possible you are putting this into s fail safe when you unplug the sensor? can you grab some scan data , graph and see if there is any abnormalities during the event ,
I am willing to try anything, what data would you like me to graph? I have the cam crank correlation but when I was able to capture this the engine mysteriously started to run and not shut right off after start up, and as of last night its still running with no problems. I was thinking maybe the phaser or the solenoid was sticking and advancing/retarding the cams as soon as the engine fired up
Typically folks post the know good cam/crank correlation with phasers unplugged mabe that's why you have the 11° swing on the exhaust cam, what's the 5 volt ref doing? Food for thought 5 volt refs can be internally shared on the voltage converter inside the pcm, dont let the wiring diagram fool ya.