95 towncar misfire on cylinders 1 and 4

[GoodSamaritan]

This is my in-laws new ride. 95 Town car executive 101k garaged, little old lady owned, it looks showroom fresh. I'm not too up on the 4.6 stuff.

Thus far it has a bad miss. He has already replaced the plugs, wires, and coil packs. A buddy of his has a noid light and checked to see that all the injectors were getting pulses from the ecm.

Cylinder 1 and 4 aren't firing. Not sure whether it's a lack of ign or fuel. I would run out and check but the car is 3 hours away. A mechanic told him the valves were burnt, but I talked him into holding off a bit, as I can't really see that happening in a 4.6. (unless grandma ran it lean for a really long time on those two cylinders, and then I'd expect the piston to go before the valves. )

So what is more likely? Something in the ign system or a couple of injectors? OR????

[marquisman]

are you getting spark? i understand parts have been replaced but, i would verify this first. same with injectors.

[zoomie]

hmmm usually thats a coil pack issue, last time i check that coil on plug and so is all of them been replaced?

[marquisman]

its got coil packs, not cops. and he said they been replaced. its a head scratcher for us non modular guys lol

[zoomie]

its got coil packs, not cops. and he said they been replaced. its a head scratcher for us non modular guys lol

timing could be messed up , or possiably the wires in the wrong order thats an edis system. two coils pers side fo the motor, kinda sucks but not as much as the cop though. also the MAF could be bad too, that would cuase it run like shite too.

[marquisman]

what about crank/cam sensors and such? how are the coils asigned? iv seen on some engins, one coil pack will control odd cylinders. maybe the coil pack aint getting a signal? did you gather the 1 & 4 miss from a computer diagnostic test?

[Gsmagnum]

Do the cars with the coil packs have an ignition module?
I know that on GM coil pack units that there is a module under the coil packs that goes bad and it will look like it is one pair of coils.

[Gsmagnum]

I see by looking for parts that there is a module for these. I think most part stores can test these.

[Lincolnmania]

module is on the firewall
i've had lousy luck with aftermarket plug wires for the 91-97 4.6's......have him try exchanging some wires around, see if the miss goes to another cyl

[GoodSamaritan]

Thanks for the response everyone.
I talked to them again the other day, and he says he tried a compression test on it. Cylinders 1 and 4 were very low. Last I heard he was pulling the heads to see what was going on.