What could be causing this speedos/engine problem?

[anticlaus105]

Recently my speedo has been acting up. Most of the time it is fine. Occasionally it goes haywire, jumping all over the place for a few seconds. Now and then it will simply fall to zero for a while before eventually picking back up again. Sometimes when this has happenes the CEL light has come on. After a while it goes off again. At it's last service System R didn't really provide too much insight simply saying a code had been generated to with a speed sensor? I may do the paperclip in the computer socket thing at some point to investigate this myself.

Last night the speedo dropped to zero for a prolonged period. While it was at zero the car wouldn't VTEC and would top out at about 6k revs. When it came back the car was running fine.

I have a recoreded clip of the speedo and rev counter (done by my other half obviously). It's about 2 megs. You can see the speedo at 0, that it's unable to go above ~6k revs and then after a bit all is fine.

http://homepages.nildram.co.uk/~aprowse/Speedo.3gp

Just right click and save to your computer to view. Doesn't work in media player but will with VLC media player that I use. EDIT: Also works with quicktime which I have just discovered will play the sound also.

http://www.videolan.org/vlc/

Cheers for any input xthumbup

 

[Duncs]

sounds like a speedo converter snag, never heard it intefering with the 'engine' though.

 

[BadBadtz]

could be that the ECU does not think the car is moving therefore the stationary rev limiter is kicking in.

 

[200BHPCARS]

Is your ODO reading counter un-effected???

Its looks like this could be an issue with the Speedo converter chip that are wired in by most import c/o's when the cars are UK preped.

I pressume you are converted to MPH??

If so let me know, i can tell/show you where to check to see if the wiring of the speedo chip might have been damaged...

cheers

andy

 

[anticlaus105]

Yeah car is converted to MPH. Haven't noticed it affect the odometer but it doesn't happen very often and when it does it only lasts for a few seconds up to maybe just over a a minute at the longest.

EDIT: Someone mentioned an alternator fault can sometimes cause this. How I don't know. Is this true? If it is the speed convertor chip how much am I looking at to get it fixed?

 

[Duncs]

they vary in price, do a quick search you are the second chap to have a snag in the last week,
think the link was to 'funky product'
the converter is normally fitted close to the 'speed sensor' which is in the gearbox.
if you have a standard air box it will be probably under it,
i will see if i can take a few pics tomorrow and stick them up

 

[C&S Evo7]

Bad badtz has the answer, no speed pulse to ecu, thinks its stationary so applies rev limiter,

I would say look at the convertor for sure.

 

[200BHPCARS]

Check the wiring around the speedo converter chip 1st.

You will need to remove the Air filter Box to gain proper access to this area.

If the wiring is fine, then i suggest a straight replacement on the Chip.

they cost £40.00 plus delivery.

We have around 15 in stock which we use for all of our imports - if you need one give me a shout and i can have it to you for £30 delivered (we get them at a discount for buying in bulk!)

Hope this helps :wink:

andy

 

[anticlaus105]

Check the wiring around the speedo converter chip 1st.

You will need to remove the Air filter Box to gain proper access to this area.

If the wiring is fine, then i suggest a straight replacement on the Chip.

they cost £40.00 plus delivery.

We have around 15 in stock which we use for all of our imports - if you need one give me a shout and i can have it to you for £30 delivered (we get them at a discount for buying in bulk!)

Hope this helps :wink:

andy

Cheers. Will have a look later when I get the chance.

Any chance of those pics Duncs? I'm a bit numb when it comes to anything that goes on under the bonnet.

If it does need replacing is it something I could manage? I'm fine when it comes to putting chips in PC's.

 

[BadBadtz]

Cheers. Will have a look later when I get the chance.

Any chance of those pics Duncs? I'm a bit numb when it comes to anything that goes on under the bonnet.

If it does need replacing is it something I could manage? I'm fine when it comes to putting chips in PC's.

Get a torch and try look under the airfilter housing towards the back of the gearbox. Its usually a small black box about an inch square with coloured wires coming off it.

 

[Duncs]

its a wiring job,
they generally come with a diagram, its 3 wires in and 3 wires out, if you are not too sure get somebody (auto electrician) to do it for you.
if you have the standard air box though it will have to be taken off.

off to get car out and take some pictures, not opened the bonnet since TGM closed it

:roll:

 

[tedg]

While it was at zero the car wouldn't VTEC and would top out at about 6k revs.

Is this the stationary rev limiter that someone else was was posting about - i think they called it 'launch control' :!:

 

[200BHPCARS]

Its an easy enough job to do -

We have the wiring/ fitting instructions as a word document i can send to you if you need to replace it.

!st thing to do -

1. Get a screw driver and take out your Air induction Box. (you will need to remove the breather pipe to the engine also) - 5mins

2. Then get a torch and look down towards the top of the gearbox for anything that looks non standard. If the job has been done properly you shouldnt be able to see the black speedo chip or coloured wires because it should be fully insulated. However this could very well be the problem.

3. Once you have located the chip (identified by the 3 coloured wires coming from a 2cm sq black box and tapped in to the speed sensor plug)
check all the wiring and re-insulate if nessesary (prob will be be the sounds of things)

4. Replace the Airbox and breather hoses and once everything is back where it should be - test drive the car and see if the problem is fixed.

5. If not then gimmie a PM and i will send you a chip and wiring instructions for £30 which will take you 30 mins to replace.

N.B - if you do replace the chip, use a solder joint and not a connector as this is the only way of assuring a 100% contact. Also make sure the speedo chip is well insulated from the weather (and the wiring) and make sure it is tie wrapped secured to avoid any vibrations rattling it loose.

This should sort your probelm

 

[anticlaus105]

Cheers all. Will have a look n see what I can do when off on Sun.

Will be nice to get my own hands dirty instead of payin someone else to for once.

 

[BadBadtz]

Cheers all. Will have a look n see what I can do when off on Sun.

Will be nice to get my own hands dirty instead of payin someone else to for once.

I would always recommend buying some latex mechanics gloves before doing dirty stuff. Grease and oil is a nightmare to clean from under your nails :wink: :lol:

 

[anticlaus105]

Is your ODO reading counter un-effected???

Watched it tonight on way home. Odometer didn't go up while speedo read zero (seems to be getting worse).

Good point - Car will effectively read lower miliage (not that it matters now it on 90 odd k anyway)?

Bad point - No VTEC while this is happening?

Good point - Could have a defence if caught speeding?

Bad point - If above defence is used it may not work n on 9 points already.

 

[C&S Evo7]

just fix it......... we're all in suspense......

 

[BadBadtz]

Is your ODO reading counter un-effected???

Good point - Could have a defence if caught speeding?

Bad point - If above defence is used it may not work n on 9 points already.

6k rpm in 6th gear is way over any UK speed limit :roll:

 

[anticlaus105]

Is your ODO reading counter un-effected???

Good point - Could have a defence if caught speeding?

Bad point - If above defence is used it may not work n on 9 points already.

6k rpm in 6th gear is way over any UK speed limit :roll:

Don't worry. If you watch video you will see I was dropping into 4th to try and get it over 6k revs while the speedo was at zero to show it wouldn't do it. Other times I was in 6th it was way below the 6k mark.

I wouldn't be silly enough to post a video that proved I was speeding. I remember a story about a Jap guy who did in a Ferrari a few years back. Think he spent some time in the choky.

One handy thing I have noticed is that in 6th the needle for the speedo and rev counter seem to go up the same amount. You can judge your speed from the rev counter.

 

[AdrianK]

I had this EXACT problem and still am having issues, had a new convertor fitted, and it has made no difference!

You can see my troubles here:

http://www.itr-dc5.com/forum/viewtopic.php?t=9971

Im not sure what to try in your case mate but my car issues were identical to what you describe, CEL light at times, error code 17 - VSS system error. No VTEC when speed = 0, etc..

Mine fixed itself when i removed the head unit etc.. so to my thinking its likely a WIRING issue not the convertor, maybe dodgy earths or a intermittant short somewhere, im going to investigate mine further.

Please do let me know if you get yours fixed first how you did it!!