2drcivic

Hey, I filled some gas today, forgot the dam cap at the gas station hence the gas tank was left open.....while driving home the speedo starts jumping around and the check engine light went on. When I got home (about 15 minute drive after filling gas) I noticed my cap missing...I went back to the gas station and got the cap back on the car, but the light is still on. I disconnected the battery and the check engine light went out, took it for another spin and the light came back on.....speedo is still not working! How the hell can that affect the speedo?

Anybody know what could be wrong and what I may have screwed up.

BTW car is a 99 civic si.

Thanks for all your help

akira

it cant affect the speedo.
Theres an issue with the ek's where the wire harness under the IM chaffes and can blow a few fuses and cause the speedo to not work.
I forget what fuses, but something to do with the alternator. someone should chime in and fill in the gaps.

si_ponz

you may need to reset the CEL the proper way with an OBD reader. I hope you dont have CEL problems now where it spews a code and there is nothing wrong under that code.

DumbasSi

The failed speedo could also easily be the VSS (vehicle speed sensor). Not related to the missing gas cap, just coincidence that it happened at the same time. The sensor is located on the passenger side on the top of the transmission.

chris_v2

I've never heard of this or seen it, so hopefully somebody can chime in with some more knowledge on this problem.

I would check the wiring to the VSS make sure everything is good and dandy, if so, replace the VSS. (of course the proper way would be to look at the data stream and make sure its not the cluster) but I doubt you have a logger.

2drcivic

Nope, I dont have a logger....Could it be that it was raining yesterday and maybe while I was driving, some water may have entered the gas tank and that screwed something?

starboy869

Not enough rain would've entered to be noticeable. Check your wiring, fuses, and go from there. The fuel system and your vss circuit are two different things.

2drcivic

Yeah, I'm sure it's different thats why I was baffled when I started having this prob. I've been having an acceleration problem for a while now, and I was trying to figure out what it was....I posted on the forum and I was told that it could be clogged cat, throttle position sensor.........but the check engine light never came on for anything....

Possible this put it over the top and what ever was causing the problem finally gave in...LOL, I don't know, but I'll check the fuses for sure

Thanks

loco_rides

iTrader: (2)

#15 fuse under the dash........ I told ya I'd fix it for ya.. LOL

kickz

iTrader: (1)

check the plug that plugs in to the VSS .. usually the middle pin turns all green
bad connection ..

2drcivic

Whats up man....Funny thing, the speedo started working fine again, but the Check engine light stayed on. I just went to my local mechanic, he connected the OBD II reader, reset the thing and it's working fine......but dam car still driving like ****! I'll bring it by some time soon so we can check that out...its just a time issue and that you are so far out....I'll check out that fuse.....Thanks a lot dude.

2drcivic

Yeah that maybe the issue, cause its working just fine now! If it happens again, I'll get that checked...thanks!

b18c_itr

reset your ECU by unplug the battery or the fuse
Speedo has nothing to do with the gas cap
gas cap code should be something like code 41
good luck

kickz

iTrader: (1)

did the mechanics tell what the codes were ?
if the #15 fuse is burnt that means your alternator is not charging ..
get it checked out sooonn time

loco_rides

iTrader: (2)

No the #15 fuse controls a few things but not the altinator... on the back of the head there is a bracket that rubs throught the wire harness and set's off an O2, vss and one other code (can't think of it right now) but all it takes is moving the harnes, repairing the wires and replaceing the fuse and all is well!!!!