Overly rich

No, not me.

Had the car MOT'd, serviced and "health checked" on Tritons Dyno Dynamics machine today. BHP was none too impressive at 279.6 (flywheel), but then I am stock apart from 1st decat and only pulling .75 bar boost. (I've reverted to the stock exhaust.)

Altogether, not too bad for a 10 year old car. However, one comment made was that the car is seriously over-fuelling on WOT. It drops right down to 10.2 by about 2500 rpm and stays there throughout the revs.

We pulled up a couple of other TT Supra charts for comparison (Ewens and Lockys) and although theirs also dropped a bit, the numbers were nowhere near that low.

The dyno operator said that it could by dodgy readings from the AF meter or O2 sensor, but the most likely culprit was the FPR diaphragm getting a bit old and weak.

Any thoughts? What should I be checking/replacing first? Triton have said that they're happy to take measurements from the sensors and troubleshoot this, but it'd be nice to give them somewhere to start...

I know that it's not a major problem and that it's far better to be rich than lean, but I'd like to get this sorted for peace of mind (and a lighter fuel bill).

PS. Had to dyno in 2nd as it's a tiptronic box and every time he booted it in 3rd it would drop straight down into 2nd.

PPS. I'd forgotten just how quiet these beasts are with a standard exhaust.

jam is nice on toast (sorry that went way over my head) lol

LOL

Maybe you should just stick to Off Topic then?

yeah think i will

Well, I have a spare FPR if you need one. In fact I think I have 2. I'd be suprised if anything is wrong with yours though.

Sounds to me they don't know how to dyno the auto's properly. Tip's are very hard to get right.

Are you able to post the dyno graphs with the boost, afr and rear wheel torque plots on here (probably on separate graphs)?

Edited to add - SRR won't provide any Flywheel figures for auto gearboxes as the figures the RR provided were not completely accurate due to the way the torque converter works. Aside from atmospherics only RWHP/torque figures are relevant when comparing like for like.

When was the O2 sensor last changed? Locky and Ewen have both fitted new O2 sensors (or at least I sold them new O2 sensors), which could explain the difference.

Stock O2 sensor replacement wouldn't make a difference once the car is out of closed loop. Something else is going on here.

Agreed about the Tip problem Homer. When Ewens was first dyno'd the graph looked like a spider scrawl apparently. But they said they now had it sorted and it seemed to go OK yesterday once they used 2nd.

O2 sensor was changed this time last year for the MoT.

Graphs attached.

Any more thoughts guys?

Sounds to me they don't know how to dyno the auto's properly. Tip's are very hard to get right.QUOTE]

 

Do you recommend anywhere for an auto?

Sounds fairly normal to me, they run pig rich as stock although that's more like at 1bar of boost, can't say I've much experience of how a stock Supra actually fuels

-Ian

Would it have made much difference that up until 10 minutes before the run it had a straight through exhaust running 1 bar?

IE. should we have pulled the battery connection and reset the ecu first?

279? So are J specs really 280? or is that down on 320?

When was the O2 sensor last changed? Locky and Ewen have both fitted new O2 sensors (or at least I sold them new O2 sensors), which could explain the difference.

:blink:bugger