HI
After heavy rain my tachometer is going nuts. its just jumping up and down. A couple of time engine did rev up, but mostly its tach. Any ideas of help? thanks...
Maybe the VSS is about to fail.
The battery voltage being low can cause this, as well. It causes all sorts of wierd things to be possible (wipers coe on all by theirselves, jumpy speedo/tach... flashing airbag lights, etc)
Purely as a guess, I would imagine that your battery is low, and posible that the rain is a coincedence.
The possibility that water is getting on to the PCM or associated wiring is THERE, but not likely. (its on the passenger side of the engine bay, near the firewall.. check for water up top of the engine...)
The other possibility is the failing sensor, as previously stated.
Ray
Battery was ok, i checked. its water thats getting on PCM.
i have no clue how its getting there. i even sprayed it with plastic before and covered it with plastic bags but its still happening.
Originally posted by Tony2005:
Maybe the VSS is about to fail.
Incorrect. A VSS would not affect the tach.
Originally posted by powerx_32:
Battery was ok, i checked. its water thats getting on PCM.
i have no clue how its getting there. i even sprayed it with plastic before and covered it with plastic bags but its still happening.
LOL I wish I knew where the PCM was actually located so I could help you out. 
Do you have an type of guards missing from wheel wells or anything? Did you totally dry the PCM before trying to cover it back up?
PCM is on the passenger side of the vehicle, topside, near the washer resevoir.
Water is likely entering from either the cowl area (firewall side of the hood, near the wipers) or from the passenger tire well, is a splash shield is missing, or was never present.
Ray
Originally posted by CSVT1214:
Originally posted by Tony2005:
Maybe the VSS is about to fail.
Incorrect. A VSS would not affect the tach.
"A couple of time engine did rev up".
If the engine was reving, it would.
"If the engine was reving, it would."
when car was at constant speed and constant rev (ie2000) all of a sudden it when to 3500.
i did dry PCM and covered it. after standing through out a night car is driving OK but tach was still jumpy and now its stuck at zero.
Originally posted by powerx_32:
when car was at constant speed and constant rev (ie2000) all of a sudden it when to 3500.
When it went to 3500, was it just the tach going to 3500 (without the engine "revving") or did the engine rev up to 3500 and you heard it and saw it on the tach.
If it is just the tach, then you know it is just an electrical issue to/revolving around the tach (or wiring).
If it is engine revving, it could be the PCM (or wiring) or the VSS (also check the wiring/connectors to the VSS). When my VSS went, it took a long time between the first time (wet and cold March) I noticed it before it actually "died" (humid and cold December).
at the beginning it was tech and revs going up. i could hear and feel the engine working harder.
but other things are just tach jumping. So where do i start checking? where is VSS?
Originally posted by powerx_32:
where is VSS?
Rear of the tranny. Autozone has info on how to remove it. You may just want to clean and dry it out first to see if that helps. Good luck.
http://www1.autozone.com/servlet/UiBroker?ForwardPage=az/cds/en_us/0900823d/80/1b/cb/ad/0900823d801bcbad.jsp#hd1-1-3
ill see what i can do. Thanks a LOT!
does anyone have any ideas how to protect pcm for the future?
Originally posted by powerx_32:
does anyone have any ideas how to protect pcm for the future?
LOL. I think what you have done is more than what most of us will do (covering the PCM). 
Re:Tony2005
This is 2nd PCM. original was changed because because it had corossion on many pins. After the rain or good car wash, does anyone else has water on that side? its unfortunate for me and hopefully not a common one(so i suggest that u guys check)
Originally posted by powerx_32:
Re:Tony2005
This is 2nd PCM.
Sorry, not so funny when it is the 2nd PCM. Didn't know you had to change the PCM previously.
As Ray suggested, "Water is likely entering from either the cowl area (firewall side of the hood, near the wipers) or from the passenger tire well, is a splash shield is missing, or was never present."
You may want to put some caulking on the cowl area and then wash the Contour to see if water is getting to the PCM area again. Of course, make sure the PCM is covered first before washing the Contour.
Edit. I wonder if you could be missing the weather stripping on the hood area.
http://www1.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/1b/bd/ee/0900823d801bbdee.jsp
check everywhere for water leaks, cowl area sounds like the culprit.
before, i have also drilled a bigger hole for draining(place where water comes down from weatherstripping). and it seems to be stopping water from overfilling and leaking inside. but also, when i sprayed front of the car, i have noticed traces of water on my plastic bag that was lined up from the end along the fender. so it seems like its getting a bit at a time through the gap between hood and fender. so, if its on a rain long enough it will be flooded.
Originally posted by powerx_32:
so it seems like its getting a bit at a time through the gap between hood and fender. so, if its on a rain long enough it will be flooded.
I would suggest going to Home Depot, and getting some of those single sided weather stripping "tapes" (the ones usually used for doors - gray or black color I think) and taping some under the hood where it meets the right (passenger) fender and see if that works. It could be that the fender or hood is not stock and was replaced with an after market part. After the driver's side fender of my van was replaced with an aftermarket part, I noticed water in that side next to the struts area under the hood after a major rain storm too.
Tony, i didn't quiet understood what i should tape.
Okay, it appears that water is seeping in between the hood and the fender on the passenger side. My suggestion is to tape some weather stripping under the edge of the hood (passenger side) so that, that area (entire edge) would not have any small gaps when you close the hood.
looking at this picture:
1) WHy does this fender has such a long sidewall. mine is narrower and shorted
2)where the drain is(below guy's hand) i drilled a bigger hole.
3) i have coved pcm below power steering container and above
so water is on top of everything
Originally posted by powerx_32:
looking at this picture:
1) WHy does this fender has such a long sidewall. mine is narrower and shorted
2)where the drain is(below guy's hand) i drilled a bigger hole.
3) i have coved pcm below power steering container and above
so water is on top of everything
As I mentioned earlier, yours could be an aftermarket part. You just have to try different ways until it works.
Not sure what drain you are talking about. I will check mine tonight.
What in the world was Ford's rationale for putting the PCM under the hood in the first place? I guess putting it in the passenger-side kick panel like they do for all their other cars was too proven, and made too much sense.
Originally posted by rearden:
I guess putting it in the passenger-side kick panel like they do for all their other cars was too proven, and made too much sense.
Unfortunately, that might also be a problem. Some of us have experienced water coming into that area too. 
"2)where the drain is(below guy's hand) i drilled a bigger hole."
I was just wondering. Did you check if the drain is clogged? Might be good to pour some water in the drain to see if it will really drain. Drilling a bigger hole won't help if the drain is clogged.
hi
drain is ok. i poured water and its all going down.
i have protected pcm to the best of my ability now
1) took pcm out and dryed it
2) coved all connectors with dielectric grease
3) sprayed wires with plastic spray and plastic bag
4) got a long sheet of flexible plastic and taped it from firewall along a fender.
5) inside colw area, covered two bolts with some silicone(they were rusty but i dont think were leaking)
now its just needs to rain...:)