160bhp?!?!?

[c70 t5]

Hi All,

Just had y car on the rolling road and it only showed 160bhp, should be 240 as standard!!!

The guys cleaned the air flow meter an it was then doing 202bhp, still not quite what it should be.

They then noticed that the car was very lean under load and was showing 0.00% co on full throttle!!!! (it was showing some readings when started/idle, but none when the accelerator was pressed, they said it should be showing 5.00-6.00%)

I'm gonna get the car serviced and hopefully with the change of fuel filter, it should be ok, i was also told if this doesnt work, it could be the flow meter that needs replacing.

If its none of the above, have any of you guys any idea of what it could be (you boys at VT come across this problem, any solutions?).

What should be my next step?

Thanks in advance for any replies.

[Bakey]

I'm sure one of the techies will probably give me a trout slap for this one but have had a similar problem (not on the t5 or a turbo'd vehicle) that was caused by a goosed CAT / Lambda sensor.

[SaffronC70]

Hi there

How many miles has the car covered ?

Did the rolling road operator mention any knocking and/or hesitation ?

What sort of fan does the rolling road use ? Bonnet up or down ?

What's the car like on the road ?

What exhaust has the car got ?

Sorry for all the questions ! I've had similar problems and I'd like to help get to the bottom of them! I've had new ETM, MAF and two lambda sensors, but my car has covered nearly 100k now, so I replaced them through 'generous maintenance'.

Chris

[volvotuning]

Hi All,

Just had y car on the rolling road and it only showed 160bhp, should be 240 as standard!!!

The guys cleaned the air flow meter an it was then doing 202bhp, still not quite what it should be.

They then noticed that the car was very lean under load and was showing 0.00% co on full throttle!!!! (it was showing some readings when started/idle, but none when the accelerator was pressed, they said it should be showing 5.00-6.00%)

I'm gonna get the car serviced and hopefully with the change of fuel filter, it should be ok, i was also told if this doesnt work, it could be the flow meter that needs replacing.

If its none of the above, have any of you guys any idea of what it could be (you boys at VT come across this problem, any solutions?).

What should be my next step?

Thanks in advance for any replies.

First of all, this rolling road looks like it used a Gas Analyser hence the CO reading. The problem with a gas analyser is that it's too slow and is about 5 seconds delayed during the dyno run. So there is no way to accurately measure AFR with a gas analyser unless you do a static test and even then the AFR changes as the temps climb. To do this properly you need to use a Wideband AFR meter which is what we use as it gives instant AFR reading, with zero delay.

Second, your AFR is supposed to be lean at WOT throttle until around 4000 rpm where it should start to richen up. So without any RPM data I cannot tell you if it's actually running lean.

Third, if cleaning the MAF made a difference then it's highly likely that you may need a new one and would certainly explain your big power loss and any bad fueling. We measure the MAF output on the dyno so we can spot a faulty one instantly.

We come across such problems regularly which is why we use the dyno for diagnostics as we can see straight away where the problems are. Do you have a dyno plot showing the fueling? That would give me a clue.

Adam.

[c70 t5]

thanks for all that advice and info. I think i will get the MAF replaced and see if that solves the problem. If not, i will get the dyno plt and see if you can make heads or tales of it! I will also find out if they used the wideband AFR meter thingy when they had it on the dyno.

Thanks once again, i will update you all once i find out what the problem is.

Shafi

[mulletboy2]

New MAF sensor - £200+
Dyno session at VT - £60 (or thereabouts)
Ploughing money at something you're not even sure about ... silly.

My 2p