Monitoring VEA EMAP sensor value?

[Zebster]

Originally Posted by Stuby

Same Here Zebster took mine into Shrewsbury, I couldn't fathom it out.
Turns out a pipe to the turbo gets blocked/damaged, Replacement cost £211.20, fitted.

Does the invoice give a name or part number for the replacement pipe?

[Stuby]

Hi Zebster,

Unable to private message you.

However the info is,

EMAP pipe Part number 31465952 list price £88.50

[Zebster]

Originally Posted by Stuby

Hi Zebster,

Unable to private message you.

However the info is,

EMAP pipe Part number 31465952 list price £88.50

Oh that's great, thanks very much.

Did you have an engine warning light?

[Zebster]

I had a brief play with my free version of the car scanner app last night and it does access the EMAP sensor reading. I didn't want to run the engine so I just checked that it was reading atmospheric pressure OK and it was (just under 100KPa, same as the MAP sensor).

I'll set it up to graph the results (same as rafikield did) and check if it gives a high value, heavily modulated outcome to prove the pipe is unblocked, or not!

I just went away for a long weekend and all was great on the outbound journey; very smooth, good MPG. But coming back last night the throttle felt dead and economy was around 10MPG down. Same tank of fuel.

[Stuby]

I had the reduced performance turtle come on.
But the week before I had the engine management light come on indicating a MAF sensor problem, however this turned out to be a split and warped plastic inlet pipe.
One thing after another.
Running a lot better possibly better than when I bought it 3 yrs ago.
Now on 102,000 miles.

Fingers crossed that’s it, for a while.

[Zebster]

So this morning I've been out with Car Scanner logging the EMAP sensor readings, results show heavily modulated readings going from around 1 to around 5 bar absolute depending on accelerator position and load. So I'm happy that the associated pipework is NOT blocked.

But the fuel economy is still worse than I'd expect, despite the car currently running fine. I've been doing long-ish journeys and filled up today to get only 45mpg after 400 miles. Strangely it did do two DPF regens in that distance, the first time took the loading down to 12g from 16g and then on the next journey it went down to 6g... possibly this shows the first regen was aborted due to driving style?

No sign of unusual heat from brake disks, so nothing binding there. And still no active or pending DTCs.

I'm wondering if it's the new winter tyres, currently on around 400 miles? I guess they do 'scrub in' a bit when first fitted and maybe the softer construction does cause more road friction?

[Clan]

Originally Posted by Zebster

So this morning I've been out with Car Scanner logging the EMAP sensor readings, results show heavily modulated readings going from around 1 to around 5 bar absolute depending on accelerator position and load. So I'm happy that the associated pipework is NOT blocked.

But the fuel economy is still worse than I'd expect, despite the car currently running fine. I've been doing long-ish journeys and filled up today to get only 45mpg after 400 miles. Strangely it did do two DPF regens in that distance, the first time took the loading down to 12g from 16g and then on the next journey it went down to 6g... possibly this shows the first regen was aborted due to driving style?

No sign of unusual heat from brake disks, so nothing binding there. And still no active or pending DTCs.

I'm wondering if it's the new winter tyres, currently on around 400 miles? I guess they do 'scrub in' a bit when first fitted and maybe the softer construction does cause more road friction?

What was your average speed on the display for that 400 miles ? What tyre pressures are you using?

[Zebster]

Originally Posted by Clan

What was your average speed on the display for that 400 miles ? What tyre pressures are you using?

Average speed was surprisingly low at 32mph. I'm currently running the tyres at the 'eco' setting of 38psi (although I will reduce this when snow/sub-zero temperatures arrive).

[Clan]

Originally Posted by Zebster

Average speed was surprisingly low at 32mph. I'm currently running the tyres at the 'eco' setting of 38psi (although I will reduce this when snow/sub-zero temperatures arrive).

very good for the tyre pressures 👍
But your average speed is far to low , you are looking for 40 + at the very least, if you get it up to 50 + without exceeding 65 mph that's where the 60 + mpg is achieved .

[Zebster]

Originally Posted by Clan

very good for the tyre pressures 👍
But your average speed is far to low , you are looking for 40 + at the very least, if you get it up to 50 + without exceeding 65 mph that's where the 60 + mpg is achieved .

It seems you were correct... I've been doing more long motorway journeys since we last discussed this and my calculated MPG when refilled yesterday is back up in the mid-50s. In fact, when I reset the trip stats during a bit of amateur hypermiling on a long motorway stretch (no slipstreaming of HGVs!) I could get the system to record low-70s. Very boring though...