£50 to whoever fixes this problem!!!

[afennell]

its a faulty speedo sensor behind the dash get a dyo test done in a garage it will confirm this, sounds weird but trust me and seem's as you've nearly bought a new car in parts you should try this

Interesting, please tell me more. Where is this sensor?

Just checking there is no confusion, My speedo is working fine, its the rev counter that dies.

[Rossyboy99]

its ubfortunatly behind the dials a wire runs up the back of footwell to dials and its a pain to get to unless a garage does it my mates car had two problems one was something to do with a pipe in the engine bay not sure on that but check all of yours top to bottom, the other was a faulty sensor unit behind the dash, he got it put on a dyagnostic machine, and told him everything not expensive but not an easy fault to find, and its weird that such a small fault causes some big problems.

so for 30 quid get yourself down a garage get the car on the dyno machine and i bet it is something simple like the sensor etc.

[afennell]

Run out of money to take her down to garages.

Can you give me anymore details, I can strip the dash easy. So it's behind the dials on the wiring loom. On the way to the foot well. Your friend had the same problem with his rev counter diying and car coughing.

[mr2nut123]

Okay just taken her for a drive and seems to be running fine. Was idling a little high to start with.

Could this be the start of a faulty o2 sensor?

Not read the whole post, but this is exactly what I had. It's probably your ignition feed wires mate. I changed my battery and alternator over, had the same problem but it was intermitent and sometimes rev counter was working, sometimes not. Small to mid-range boost was like it was misfiring, not smooth at all. If I did full boost the car would hold back a bit and then shoot off to full boost fine until I let off. The 2 wires were re-loomed and chamoooone, it was working spot on again. Get a good leccy to test all the looms, I bet it's that. £50 please

[afennell]

Not read the whole post, but this is exactly what I had. It's probably your ignition feed wires mate. I changed my battery and alternator over, had the same problem but it was intermitent and sometimes rev counter was working, sometimes not. Small to mid-range boost was like it was misfiring, not smooth at all. If I did full boost the car would hold back a bit and then shoot off to full boost fine until I let off. The 2 wires were re-loomed and chamoooone, it was working spot on again. Get a good leccy to test all the looms, I bet it's that. £50 please :lol

Were your symptoms exactly the same,

The rev counter dies completely then the car start running very rough. Drive for a bit and the rev counter starts working and the engine start performing properly.
Also looks like lots of black soot around the exhaust after the problem.
Do you know what wires were replaced? £50 if you can and I replace them and it works!!!

[mr2nut123]

Not read the whole post, but this is exactly what I had. It's probably your ignition feed wires mate. I changed my battery and alternator over, had the same problem but it was intermitent and sometimes rev counter was working, sometimes not. Small to mid-range boost was like it was misfiring, not smooth at all. If I did full boost the car would hold back a bit and then shoot off to full boost fine until I let off. The 2 wires were re-loomed and chamoooone, it was working spot on again. Get a good leccy to test all the looms, I bet it's that. £50 please :lol

Were your symptoms exactly the same,

The rev counter dies completely then the car start running very rough. Drive for a bit and the rev counter starts working and the engine start performing properly.
Also looks like lots of black soot around the exhaust after the problem.
Do you know what wires were replaced? £50 if you can and I replace them and it works!!!

Sure. Exactly the same problem with mine. Took it to the gym after new alternator, absolutely fine....until the brand new battery also died a few days later. Rev counter dropped and the CD player turned itself off. My lights would pop up slowly etc. Then all of a sudden it would bounce back into action a few hours later and work perfectly then all of a sudden die again once the battery had lost its charge. Dont forget that the battery powers your ECU controlling fuel and air, if this doesn't get enough power it can't make quick decisions when you put your foot down, making the car lumpy depending on the intermitent power problem.

All I was told by the garage was that it's the black and yellow wires which are the 'ignition feed wires' and they had to be re-loomed. This wasn't too expensive and sorted it no problem.

[afennell]

sounds very Similar, but my stereo works fine, and so do my light, they are all full power. Also I have over 14v at the battery even when the car is running rough. The battery never runs flat

Defiantly going to check these wires this weekend and see if they have any resistance on them.

[Driftlimits Performance]

black and yellow wires which are the 'ignition feed wires'

OI! If it's the black and yellow wire it's my £50! Said it on page 2

[mr2nut123]

black and yellow wires which are the 'ignition feed wires'

OI! If it's the black and yellow wire it's my £50! Said it on page 2

Ahhh but you didn't specify exactly what he needed which is what he's asked for. I've said exactly what he will need to fix it. I'll go halves then

[afennell]

Going to check the wires this weekend.

Probably be able to find this out with the multi meter but there are a few yellow wires, do they go into to fuse box socket or the loom that plus into the socket in the fuse box.
Hope that makes sense

[afennell]

Both the yellow wires are fine in the grommet on the alternator. When tested with my multi meter to the fuse box in the engine bay im getting the buzzer and a 0 on the screen.

With the black in the middle I get a response from a few wires, I suppose this is because its an earth. Hear is what I get, probably normal but thought I would ask you kind people.

Solid black no buzzer and 0.68 on the screen
Solid red gets a buzz and 0.47
yellow and black gets a buzz with 0.031
yellow and green no buzz 0.845
Both solid yellow get no buzz and 1
White and Black gets a buzz and 0
solid white is 1 no buzz
white with red strip gets a 1 and no buzz
black with white strip gets a buzz and 0.002
brown is 0 with a buzz
red with a black stripe 1 no buzz

Is this okay?

[mr2nut123]

Both the yellow wires are fine in the grommet on the alternator. When tested with my multi meter to the fuse box in the engine bay im getting the buzzer and a 0 on the screen.

With the black in the middle I get a response from a few wires, I suppose this is because its an earth. Hear is what I get, probably normal but thought I would ask you kind people.

Solid black no buzzer and 0.68 on the screen
Solid red gets a buzz and 0.47
yellow and black gets a buzz with 0.031
yellow and green no buzz 0.845
Both solid yellow get no buzz and 1
White and Black gets a buzz and 0
solid white is 1 no buzz
white with red strip gets a 1 and no buzz
black with white strip gets a buzz and 0.002
brown is 0 with a buzz
red with a black stripe 1 no buzz

Is this okay?

In all honestly, take it to a proper leccy and pay a flat fee for him to fix it. It's so much easier!

[milesy_boy]

Hi there, I've just cured the exact same problem on a Volvo S70, had the problem for.....6-8 months, never out the garage! Here's what happened to me, intermittent problem with mis-firing/over fuelling, when the car was missing badly, I noticed balck smoke raging from the exhaust and it was exactly as u say, rev counter dying, had to rev high to get home and when I was turning into drive it stalled and would not start!!So new plugs etc, (the usual mis-firing suspects) checked the ecu, came up with an O2 error, replaced the Lambda sensor, went fine for a few weeks, then back again, got idle control valve cleaned out, went fine for 2months then came back, so everything pointed towards a faulty ECU, went to ECU repair place and no ECU fault!! eventuallt they traced it to a faulty air flow meter,so the air flow meter caused a "diverse signal" and it showed as a Lambda error????? So I would suggest checking Lambda sensor, airflow meter and check the ECU for codes, will send you my bank details later for the £50! lol
Hope you get it fixed as I know how annoying this is!

[afennell]

Thanks for the input, this problem is very annoying.

02 sensor is an interesting idea, it's probably one of the few items I have not replaced.

I have a rev3 so no air flow meter, possibly worth replacing the throttle body as I believe that has the idle control sensor and throttle sensor.

Ecu has no error codes and has been replaced.

I have lost interest with her at the mo, she it going into Westfield’s for an mot at the end of the month, thay are going to keep her in for a week, think i'm just going to wait until then.

I'm tempted to replace the 02 sensor due to the Tesco petrol problems killing them. I did fill up with the 99octan a few times. Can’t think why that would kill the rev counter.

Thanks for the help I will let you know when I finally get this fixed and who has won the prize.
Thinking about selling the car when it's fixed.

[afennell]

Just thinking about what you said, arn't the s70 2L turbos as well, and a new air flow meter fixed the problem. How old was the car.

Feeling good about this.

[afennell]

If the problem was caused by a faulty air flow meter on the Volvo,
and the rev3 turbo does not have a air flow meter,

Am I correct in thinking it uses a map sensor instead, and could this cause the problem.
Think im going to replace it anyway.

[milesy_boy]

Hi there, not been on for a few days, my S70 isn't a turbo, but the symptoms of over fuelling are 2 similar here, there is something in a sensor that adjusts ur fuel and i think that is ur problem?? check next time it plays up to see if there's black smoke coming from it or if the exhaust area has heavy carbon deposits? (Got an O2 sensor here, a 4 wired one with the gasket, looks nigh on brand new that, if u wanna replace ur old one then make an offer) though i dont think it is ur O2 sensor????????
I got really hacked off with my 2 as well, had an electrical fault for months and cost me hundreds, so annoying when any car develops one of those "intermittent" faults! You will fix this and get back to liking ur car again, hang in man, been there!

[Jamitsi]

have you thought about an ignition module/sensor
a guy with an FTO had this go and it knocked out his rev counter
but still ran out and every thing else worked fine

plus i have had a few of these go on an old car(little Citroen AX GT)
and it used to kill the motor. then it would work fine after a while.
apparently it over heats and then goes faulty, open bonnet and cool engine and it worked fine again. very intermitent

just a thought. don't know where the ignition module is on the mr2 though
someone will know.

HTH
jamie

[LJS @ Rogue]

You say you have checked earths ?

Check the main ECU ground cluster that are bolted to the inlet manifold near the alternator (Remove / Clean and refit tight). Also the two small grounds that plug the chassis to the gearbox and head cam wheel end.

Lyndon.

[3sgte]

don't mean to put a dampner on things ,but my mate had a problem with his rev2 ,had overfuelling ,stalling, erraitic rev counter plus some others including a fuse blowing everytime he tried to start the car .

His case was the wiring loom going into the boot from the engine bay was all cracked ,from years of heat i suppose .and water had got in causing more problems .we could replicate each problem in turn depending on how we wiggled the loom .
We replaced his entire engine loom for a good one ,and all the problems went away