Hi,1st off sorry for recent erratic posts,but this romraider business has stressed me out.ha ha.
I've now finally got it connected and did a log last night.
I want to know if my maf is on it's way out.
How can I use romraider to do this and what file type can I post up.
On the log I did the car only actually drops to 500 rpm although the needle on speedo looks like it's about 200.

 

look at Maf voltage with ignition on but engine not running.

 

In romraider open up the Learnt Values (i think its under the tools menu) and post a screenshot. If the a/f corrections under A,B, C are high it could be a sign of dead maf, air leak, bad map etc.

 

use google sheets to post your logs bud. upload them then paste the link. here,s one of mine for an example :
https://docs.google.com/spreadsheets...#gid=283045888

 

https://docs.google.com/spreadsheets...it?usp=sharing

my log from last night,not sure if ive logged right paremeters but its line 363 where the rpm dropped when i got to a junction. the volts and g/s are there for maf.
its logged as 500 odd but on the speedo the needle looks like its nearly zero.
i didnt do the ltv or whatever its called but im gonna go and do it now.
is there any other sensors that can cause the revs to drop that i can check with romraider?
thanks guys.
justin

 

Hi stig, maf was 0.66 from cold,engine not on.
It was 0.7 when I got back from a hard drive.
Cheers.

 

pics

 

Maf is fine then

 

those AF corrections dont look bad at all, another decent way to check is to compare the wideband readings with what your fuel table is calling for in the map. You can log fuel final base (AFR) and compare it to wideband readings. If you find that at higher airflow there is a bit of a discrepancy then the MAF could well be in the early stages of failure. A simple air leak would give similar readings so be sure to rule out the simple things first.

 

Thanks for reply.
After taking it out last night it drives fine when I'm driving it hard.
Maybe I'm just chasing my tail! Ha ha.
It's just got this little habit of the needle on speedo dropping too nearly zero but looking on the logs,it's only dropping to 500 odd.
I thought it was air filter box not seated properly so put standard filter back in and on the initial drive after changing filter it didn't do anything bad.
But next day it does it almost immediately.
Changed filter for a new one and again initial drive for a good half hour and it didn't do it.
But again next day it will do it.
But if it's only dropping to 500rpm then I suppose it's ok.
I was just concerned if the maf was on its way out before I do my track day next week.

 

if you reset the ECU what happens?

 

In what way?
I have reset ecu about a week ago when I tried a different maf?

 

in terms of the revs dropping off - if you reset the ecu and then start the car does it hold revs OK or does it have the same problem?

Resetting the ECU clears the LTV info - specifically the airflow corrections so if that has an impact on the idle then it could point to one of the sensors mucking about.

 

I can try tonight, but I think yes initially it will be OK but if I Park car up and leave it, next day probably do it.
I had a recon gearbox fitted about a year ago and the guy was also selling a new speed sensor? With it but I just bought gearbox. What sensor would that have been?

 

It won't do it on the cold cycle from start and doesn't do it every time.

I had a few days of taking things off the car, cleaning and putting back.
Intercooler to throttle body,maf off and back on etc.and after every time on initial drive I thought it had gone for good but come the next day it would happen at a random time.
Also cleaned iacv. New gasket.
Apart from this minor thing the car is a beast.
Really good mid range torque and is really a rather rapid Road car.

 

First division on the taco is zero, second division is 500, third is 600, fourth is 700 and so on up to 1000, I would stop worrying about it and just drive it

Surprised no one else pointed that out ..

But take the idle valve off and clean it out really well, that means moving the shuttle radial to each extreme and cleaning as well, but you need a brand new gasket from Subaru before you take it off as the old one will suddenly change shape to the extent it cannot be reused

You can't use a laptop to clean the cr*p out

cheers

bob