2000 Taurus P0301 Misfire
i switched coil and plug miss didn't follow. my fuel injectors are spraying good and got the right amount of compression i took the upper intake off to put alittle oil into the cylinder to see if it would bypass the valve and the oil stayed didnt leak pass the valves. need some help from here
Can you duplicate the misfire? what scan tools do you have to what scan tools do you have to work with here? If you have Factory Ford or and Alltel have you ran the Power Balance test to verify the misfire? I have I have seen many technicians get burned on these older Ford's by diagnosing the effect and not the cause. I have seen these things shut off fuel to save the cat with just a very slight
Do you have a scope? In the first waveform The blue CH A is a pressure transducer in the tailpipe while cranking and 1 cylinder has a higher exhaust pressure pulse. The red CH B is the relative compression The tan CH D is a pressure transducer in the intake manifold and 1 cylinder has a low pressure pulse In the second waveform, If you scope the secondary and do a brake torque, you could
The first thing I would suggest is to verify that cylinder 1 is really the cylinder that's misfiring. On some of the older stuff, cylinders would sometimes be reported incorrectly. You could be chasing your tail.
Check the valve springs, they break often. Surprisingly they will pass a cranking compression test.
exactly. using a lab scope or Vantage to check relative compression with a synch will lead the way, then an in-cylinder test for more information...I have run into broken valve springs as well. A compression gauge may look just fine, meanwhile there is a sealing issue that can be detected with a scope.
Over the years, I have watched many people struggle finding the cause of a misfire. Back to the basics, we need the proper amount of compression, the proper amount of spark at the proper time, the proper amount of fuel injected, at the proper time, and the ability of the cylinder to pump air. In reading your post, I don't see where you addressed any of these much needed things, except the
I'm with Daniel here, I would do a running compression test. Best way to check for broken valve spring outside of visual test or using a pressure transducer.
Daniel, read Albin Moore's post, it is excellent! Ray
I can appreciate you reaching out for help on this one. It can be uncomfortable to do so, but asking for help can be the catalyst for change and bettering yourself. Anyone that knows me knows how passionate I am about training. For me, training helps to remove the pain in the service bays. I found, early on, that there was no tree branch that I could touch after a hard day in the bay that would
Brin, The points you made are very necessary. If a tech doesn't know how to analyze the data they are seeing, that fine. If they will at least post all the info ( VIN, ALL Codes not just the ones in the module controlling the "problem system", Freeze Frame data , actual results from tests completed eg, voltages, pressures, scan tool used, scan tools available to use), here many top level guys