Smart Ford guy help please! Late model question

jaybee · December 15, 2006, 05:21:07 PM

My '95 Ford Windstar 3.8L suddenly has a dead cylinder miss. It smells heavily of gas and is throwing codes:
P0340 Camshaft position sensor
P0302 Misfire cylinder 2

Monday I replaced a serpentine belt tensioner which sits in the vicinity of the camshaft position sensor, which sits where the distributor would normally go. Is it reasonable to think I might have knocked the plug loose on the camshaft position sensor? Hoping it isn't a timing chain, but shouldn't it throw misfires all over the place in that event? It doesn't try to backfire or anything of that nature and the misfire is very steady, not intermittent.

enjenjo · December 15, 2006, 05:46:59 PM

Sounds reasonable. You can also switch the plug leads on the coils to see if the problem is there, each coil fires two cylinders. It's not uncommon to have a coil on one of these go bad.

tomslik · December 15, 2006, 06:54:44 PM

cam sensors take a dump on those too...
usually squeek like a belt or tensioner AND it takes a special tool to line it up (unless you b feelin' lucky)

oh yeah, head gaskets are a problem too....
merry christmas;)

jaybee · December 15, 2006, 10:10:37 PM

Thanks for all your encouragement.

Fortunately I did the head gaskets some time ago. Felt lucky to do the job in only 2x flat rate...what a pain!

I'll keep my fingers crossed that the sensor doesn't need changed. My wife took the car to Autozone to get the codes read because I knew I'd be very short on time today. Now that I'm home from work and office Christmas party and can read the ticket it says "The PCM has determined that a malfunction exists in the electrical circuit for camshaft position sensor 'A'."

tomslik · December 16, 2006, 03:19:37 PM

Quote from: "jaybee"Thanks for all your encouragement.

Fortunately I did the head gaskets some time ago. Felt lucky to do the job in only 2x flat rate...what a pain!

I'll keep my fingers crossed that the sensor doesn't need changed. My wife took the car to Autozone to get the codes read because I knew I'd be very short on time today. Now that I'm home from work and office Christmas party and can read the ticket it says "The PCM has determined that a malfunction exists in the electrical circuit for camshaft position sensor 'A'."

ya know, it's possible to break it (the plastic part of the sensor) putting a belt on, if THAT'S all it is, you can just plop a new one on but if you have to yank the housing, THAT'S when you need the tool....
btw, if you've got to get to the backside of that eng (like for plugs), it's easier to pull the wiper assy out (the whole tray, not the linkage;) ).

i work on a lot of windstars.....

jaybee · December 16, 2006, 05:40:51 PM

Thanks for the tip on the wiper tray assembly. It isn't an obvious solution but it makes a huge difference. In Googling P0340 I find some information indicating that this could be caused by a bad diode or open phase connection in the alternator. I've done a visual inspection and can't find anything obviously wrong with the coil pack, CPS, or wiring. Any hints on how to determine if it is in fact the CPS?

jaybee · December 17, 2006, 07:23:33 PM

OK, after going around and around with this dead cylinder the cause is...#2 injector is always on. I just replaced the PCM a year ago because #6 wasn't firing at all. Is there a cause of this that DOESN'T relate to a bad PCM?

tomslik · December 17, 2006, 07:47:37 PM

the computer grounds the injector to make it squirt sooo, it MAY be the puter or bs info to the computer (like a bad cam or crank sensor)
don't know how you're checking it but if you've got access to a $5 noid lite...and it flashes...it's PROBABLY not a puter prob.
if it doesn't flash, check to see if it's got power to one of the wires to the injector, if so, you got a bad puter..

jaybee · December 17, 2006, 09:41:12 PM

Quote from: "tomslik"the computer grounds the injector to make it squirt sooo, it MAY be the puter or bs info to the computer (like a bad cam or crank sensor)
don't know how you're checking it but if you've got access to a $5 noid lite...and it flashes...it's PROBABLY not a puter prob.
if it doesn't flash, check to see if it's got power to one of the wires to the injector, if so, you got a bad puter..

I checked it with a noid light. The light is on steady the whole time the engine is running. No flash at all, like it's grounded at all times.

tomslik · December 18, 2006, 05:18:30 AM

sounds like a computer prob OR the wire is grounded (pinched, maybe?)

jaybee · December 18, 2006, 09:33:14 PM

Yup, PCM shorted through the injector driver. Thanks and I'm glad that's done. This van has treated me really well but I've done nothing but work on it for the last week.

Crosley.In.AZ · December 18, 2006, 10:29:55 PM

Quote from: "jaybee"Yup, PCM shorted through the injector driver. Thanks and I'm glad that's done. This van has treated me really well but I've done nothing but work on it for the last week.

good to see it is fixed.

that ol tomslik is a hellofaguy if ya know what I mean.[/b]

);b(