03 Buick Park Ave intermttent no start

[carbtech72]

got a problem child from another shop. 2003 buick park ave 3.8 supercharged. randomly wont start, never stalls, once you shut it off it sometimes wont start. P0300B is the only code. Got it to duplicate the problem and have 55 psi fuel pressure, good spark, good pulse at injectors, crank sensor is registering a signal on datastream. Map sensor reading is 29.83 inHg at sea level. This came from another shop where they gave it new plugs and wires and then ran out of guesses. Im leaning toward a bad crank sensor, ive had one before where it showed up on the scanner datastream but did not fire. Anyone else run across this before

[ncautoshop]

Only way to know for sure is get the scope hooked up and take a look. I like to do a cam and crank together and find a known good waveform to compare.

 

Sent from my SCH-I605 using Tapatalk 2

 

 

[nick]

^{Ive had many of these with bad crank sensors. Intermittent no start. Usually when they warm up they act up. If this is one of the ones with the ignition modules below the coil pack. Ive had a lot of issues with them also causing the same issue.}

Edited March 18, 2015 by nick

[ATLAuto]

Try grabbing the wiring harness near the sensor when warm, and seeing if the engine hiccups.

 

Also, yes, I agree. You need to scope that sensor not just look at the datastream.

 

I'd also scope the fuel pump for a bad spot on the motor.

[carbtech72]

I've had that same problem before. Caused by a bad crank sensor

[alfredauto]

Swap in a known good ign module. If there's a ckp signal and rpm on the scanner the crank sensor is probably OK. There are ways to test the module and coil pack but in 2 minutes you can plug in a different one. Another thing is check and see if the balancer is broken, throwing off the timing.

[cdhowell]

You guys see how old this is?

Edited March 21, 2015 by cdhowell

[alfredauto]

Lol went to the junkyard by now