03 ls trouble codes... please help

[ir1680]

i have an 03 lincoln ls v8 w/ 80k miles. car started running crappy so i checked into it and replaced all my plugs, valve cover gaskets, and all the coils. i'm still getting codes for ignition coil malfunction on cylinders c,f,g,h. what controls when the coils fire? i've heard from one guy that there are 2 ignition control modules. is this info correct? what else could be wrong?

 

[beaups]

I've read elsewhere on the board that your symptoms would be indicative of a bad camshaft position sensor.

 

[ir1680]

i went to the dealer and talked with the mechanic. he said given the specific coils that are out, and that i've replaced all of them that i'm likely getting a false code. apparently when the car sees a bad coil it shuts down the injector for that cylinder. which creates a miss if its getting a false code. so i hooked up a noid light to the coil connectors to verify that they are getting signal. they are getting the signal to fire. he says that a "rf modulator" in the alternator can go bad and trip up the ecm. so i unhooked the power wire from the alt. and ran the car on the battery. it ran great, no miss or codes. so i'm replacing the alt. i'll let you guys know how it pans out.

 

[beaups]

well I believe is no rf modulator in the alternator...unless the engineers thought people might use it to hook their xbox up to their old tv's

however it's not inconceivable that a failing alternator could create enough interference to confuse the pcm. And you appear to have confimed it!

 

[Quik LS]

+1

 

[ir1680]

alright... i'm completely confused again. i bought a new denso alt. for my car from the dealer and installed it tonight. i'm still having the exact same problem. no changes in coil codes or the miss. now i guess i'm down to checking power connections and all the grounds. wheres is that pcm anyways? this crap has got me kicking around dumping a carb'ed 351w and a t-56 instead of my 4cyl v8. i'll give it one last try then i'll have take to the lincoln dealer.

 

[Frogman]

Are you sure the new alternator is good? Just because it's new, it doesn't mean it's good.

 

[ir1680]

i ordered it new from the dealership, its the same manufactur as the original. it charges within spec. i'm gona check all my power connections that i can find today. hopefully there is one all corroded up, something easy. the ignition control module at the dealer is $949.