WS6 misfire/hard start
Thread Starter
Launching!
Joined: Jan 2016
Posts: 224
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WS6 misfire/hard start 2002 WS6...Car is misfiring and at times will not even start. Pulled codes and one was lost communication I believe. It will run fine on a cold start, and start misfiring the warmer it gets. We have changed crank sensor,IAC,TPS,MAP and even swapped ECU and flashed and loaded tune. Car is still having the same issue. Is it possible the coolant temp sensor would cause this? It thinking the car is running hot and pulling timing/fuel maybe? Sort of at a loss.
Have you checked fuel pressure?
And check for fuel pressure drop when you turn the key off it should drop real slow and then kinda hang out. If it drops fast and down to 0 the check valve in the pump is bad and will cause long/hard or no start issues. Also of course make sure it is making proper pressure.
And check for fuel pressure drop when you turn the key off it should drop real slow and then kinda hang out. If it drops fast and down to 0 the check valve in the pump is bad and will cause long/hard or no start issues. Also of course make sure it is making proper pressure.
Not very likely the coolant temp sensor will do that. In 20 years as a tech I haven't seen that happen. It can make it run rich if it's dead though because the data usually defaults to -40 degrees.
Did you try the cam sensor? Cam sensor can cause your issues. Check the wiring carefully too. I've seen some bare harnesses at the connector.
Also check the grounds on the back of the driver cylinder head, that's a common source of issues.
Did you try the cam sensor? Cam sensor can cause your issues. Check the wiring carefully too. I've seen some bare harnesses at the connector.
Also check the grounds on the back of the driver cylinder head, that's a common source of issues.
Thread Starter
Launching!
Joined: Jan 2016
Posts: 224
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We have just about replaced everything....Its weird that is seems to run fine in closed loop, then when it warms up and goes into open loop it starts acting up...All wiring/grounds have been checked and are fine. The only thing left that I can think of is the reluctor. At time it will shut off so fast the belt squeeks...last night we tried starting it and it had a MAJOR back fire...
Check or replace the 02 sensors. I've seen one run perfect when cold before and as it warmed up went to **** because the 02's were dead. The PCM doesn't read the 02's until they/the engine is warmed up.
It's in open loop (not using feed back from certain sensors) when cold, closed loop when warm (using feedback).
So it goes to **** when it goes to closed loop. That means that most likely one of or more than one of the sensors not used in open loop is acting up and when it starts reading that sensor it goes to ****.
Again, seen that before with 02 sensors.
So it goes to **** when it goes to closed loop. That means that most likely one of or more than one of the sensors not used in open loop is acting up and when it starts reading that sensor it goes to ****.
Again, seen that before with 02 sensors.
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Joined: Aug 2014
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From: Houston, Texas
I agree with the O2 sensors, they are not used until car is warm. I would change them, I have had a very similar occurrence if I drove my car in the rain the drivers side O2 would die and it be misfire city and time to polish the tips back up.....