lean condition on crown vic

[peakay]

Hi there,

i recently failed CA emissions testing on my vic. I had been getting an intermittent rough idle and check engine light that turned out to be a lean condition on the driver's side. i replaced all 4 of my 02 sensors to make sure that wasn't the problem (and for preventative maintienance), but i still get the lean error.

i've checked the intake and cannot find anywhere there would be an air leak that would cause a lean-out on only 1 side of the engine.

Anyone know what the likely cause is? the only thing I can assume is some sort of injector problem.

thanks, -Paul

[marthur22]

Re: lean condition on crown vic

Paul -- my last CV had a bad cat. converter on the left side. I had it replaced. The Ford dealer cleaned the injectors but still had rough idle on start. After cleaning the air intake system and putting on a new air cleaner it seems to run much better. Also... does the floor under the gas pedal heat up?
Mike

[peakay]

Re: lean condition on crown vic

Paul -- my last CV had a bad cat. converter on the left side. I had it replaced. The Ford dealer cleaned the injectors but still had rough idle on start. After cleaning the air intake system and putting on a new air cleaner it seems to run much better. Also... does the floor under the gas pedal heat up?
Mike

Hi Mike,

No, I am not getting heat on the floorboard.

What did you do to clean the air intake system?

Thanks, -Paul

[marthur22]

Re: lean condition on crown vic

Paul-- just take of the air filter and inspect/clean ducts. I also failed to mention a COP ( coil over plug ) was bad. You can either replace them all ( expensive ) or buy one COP and go thru each cylinder with the new one until the engine smoothes out. The problem with that is if there are two bad coils .... you've only fixed half the problem .... so maybe buy two? ?
A plug was also loose and all 8 were replaced. About $24.00 dollars.
ebay has pretty good prices on Motorcraft plugs and aftermarket COPs.
Just make sure they are for the 4.6 L CNG engine.
Hope this helps.
Mike

[CNG MOTORS]

Re: lean condition on crown vic

The coils are very common failures on these engines. $10 each on Ebay. $65 each from the dealer. While you are at it replace the plugs but not with platinum plugs. Cheap AC Delcos will do.

[peakay]

Re: lean condition on crown vic

Thanks guys. I already replaced the plugs, which made the car run noticeably smoother.

as for coils, i do not see a coil on plug arrangement like on my bmw. it has a conventional plug wire with no coil above the plug.

even so, the error message i am getting is lean condition whereas a lack of spark would produce a rich condition, right??

thanks!

[Kevin Fern]

Re: lean condition on crown vic

Hello, do you have a way to look at the fuel trim numbers?, if you are getting a repeat lean on bank one, I would look at the fuel injector(s). The fuel trim, short term and long term will give me an idea on how bad the problem is ie. multiple cylinders etc, also lean conditions in cng vehicles also lead to misfires, is there a misfire code showing up? they would be from PO300 for random and 301-308 specific to a cylinder. Kevin

[peakay]

Re: lean condition on crown vic

Hello, do you have a way to look at the fuel trim numbers?, if you are getting a repeat lean on bank one, I would look at the fuel injector(s). The fuel trim, short term and long term will give me an idea on how bad the problem is ie. multiple cylinders etc, also lean conditions in cng vehicles also lead to misfires, is there a misfire code showing up? they would be from PO300 for random and 301-308 specific to a cylinder. Kevin

Hi Kevin,

I am not getting the other codes and do not have a way to look at the fuel trim. I can check codes again, but I have not seen the misfires.

Someone else on the yahoo group recommended the following to clean the injectors. Is this adviseable? Easy to do??

I have cleaned injectors on my 99 CV by opening the coalesing filter
cylinder filling it with "SEAFOAM" injector cleaner and running the
engine. It make take several applications to bust things loose. I've
found it's not uncommon at all to find clogged injectors in dedicated
vehicles.

[turbocohen]

Re: lean condition on crown vic

one by one remove the injector lead while the engine idles. note the ones that do not change rpm as much. remove the rail and switch injector location then retry. If the same injector is dead again clean em.
DO NOT clean injectors with alcohol or gumout as that will help set deposits or shrink internal orings. instead, shoot them full of stoddard solvent, gunk 5 minute oil flush or kerosene while energized with a 6v lantern battery. An easy way to do this in the shop is to pour a small amount in a rubber tipped air nozzle and blow it in. Do this several times a day and let the injectors soak for a weekend then blow the excess out and reinstall. If this does not solve the problem put in new ones and avoid stations that do not use a dryer. Moisture above -50 dew point along with some oils introduced into the fuel system are a good way to polarize compounds that oxidize easily and form gum like deposits and facilitate sulphur buildup as well. solvents will not remove sulphur well and if they are in there they aint coming out.