4.6L in an '01 Lincoln Continental. P0306 code. Been fighting this code for several months now with no luck. The only time the code comes on is when it is idling. 140K miles on engine.

Another annoyance is that it never fires up the first time you crank it. let go of the key and crank it again and it starts right up almost always. Sometimes it has to be cranked a third time.

Replaced plugs first off and no help.

Swapped coils with another cylinder and no luck. The misfire did not move to the other cylinder.

swapped injectors with another cylinder and still no luck.

Today I put a fuel pressure gauge on it and noticed something out of the ordinary. When I turned the ignition on the fuel pressure did not rise. Cranked the engine, did not rise. Cranked the engine a second time, it starts right up and the fuel pressur comes up to 30 PSIG. Shouldn't the fuel pressure come up when I turn the ignition?

Last Christmas I had to drive to Tulsa, 1500 miles. I did it non stop except for fuel and food. The check engine light never came on 'till I got to Tulsa.
The first red light I hit and let it idle for a couple of minutes the check engine light comes on.

Any ideas? I know this is not truck related but I also know there is a wealth of information on this site and I am at my wits end.

Thanks for any help

Steve

 

has a few issue with carbon getting stuck between the intake vale and seat on these cars.ended up having to pull the head and rework the vales.the intake draws a bunch of oil into it and ends up getting baked then it gets sucked into the cylinders.when the heads come off on these engines i have the intake vatted to remove all the carbon from it so it dosnt happen again.

 

Thanks for the response l-m tech. What do you mean "vatted"?

 

have it chemicaly cleaned in a hot tank that has chemicals that remove the material thats built up inside of the intake.

 

Well is it really missing when it posts the code? I would check for a vaccum leak particular on the runner and seal for that cyl. I believe by your description you have a bad check valve in the fuel pump or a bad fuel pump changing that should fix the slow to start problem. You should also be able to hear the pump run for 2-3 sec when you first turn on the key before you start if not then there is a wiring / pcm issue. As a last resort I would run a compression test to see where # 6 stood in relation to the other cyls.

 

OK l-m tech, I call vatting "hot tank". So I understand what you mean.

And wtroger, yes it does idle rough. When I come to a stop the engine goes down to an idle and is smooth for awhile and then after a few seconds it begins to stumble, the smooths out again. It seems as if it cannot handle the load as the A/C compressor cycles.

Your idea of the check valve makes sense. The fuel pump does go when you turn the ignition on but pressure does not rise. I think I will replace the FP just for grins.

I have been reluctant to do a compression test but I guess I should. I guess I don't want to know the results. Havn't been working much and can't afford that kind of expense.

Thanks Guys

Steve

 

Well, I did the compression test thing and you were right. 60 0PSIG at # 6 cylinder. The others were all over the map. Front bank read (left to right) 175-60-145-140 and rear bank reads 240-245-195-195. I think the high readings were from oil getting into the cylinder when I removed the spark plug. I don't think thats normal compression. I guess I know what I'm going to do Easter vacation.

While I'm at it I think I will change the fuel pump.

Thanks for all your responses
Steve

 

Pulled the outboard head off yesterday and there is a pie shaped burn spot in one of the intake valves. It is at the machine shop now.