Weird mapping issues with blow through MAF

[Fusion Ed]

I honestly don't know, and being as you are so far its not easy for me to look.

 

[danr]

`flowing back to front? seems obvious, but ..

 

[skiddusmarkus]

Yah that crossed my mind Dan, but it has a massive arrow welded into the metal .

 

[campbellju]

RF shielding is normally metal rather than rubber but that will also help. You have put the sensor in a metal box which is a good place to start so I'd expect if you have an RF problem it's the cable rather than the sensor. To screen a cable from electromagnetic interference (EMI) you use a screen that you earth at one end. Earthing screens at both ends can induce ground loops and create different problems.

Prevention is better than cure, make sure all your sensitive signal cables are away from RF sources (Ignition, starter, alternator etc) and where they need to cross do it at 90deg. Two cables running parallel can induce noise. I shield mine in plastic ducting to give some RF protection but mainly additional mechanical protection. With an electrical background I also have cable OCD ;-)

Check your earths. Are both MAF's earthed locally as well as at the ECU? If they are earthed locally is there anything else earthed at the same location inducing a ground loop?

It could be the sensor itself but checking/cleaning earths and RF sources is never a bad place to start.

 

[PobodY]

Could you put a ferrite lug on one or more of the wires to rule-out the RF? - I'm sure I've got a couple of old ones sitting around, and that's a common way to prevent cross-talk in control wiring isn't it?

 

[Fusion Ed]

It wont be interference.

 

[Fusion Ed]

Best thing is to get a datalog of the problem. EVERYTHING else is guessing.

 

[skiddusmarkus]

Got the new crank pulley on now(thanks Bob), so hoping to go up tomorrow and do some data logging.Not that I know how to so hopefully it's pretty easy to do on Nistune.Anyone know how?
Going to log both the draw through and blowthough so I have a comparison.

 

[Fast Guy]

Very easy on Nistune. connect to consult the hit the log player then press record.

 

[skiddusmarkus]

Did some logging today and saved the file, what's the best way of showing it on here?

Just looking at it, the blow through reads between roughtly 0.7-1v more than the draw through at the same rpm and is massively overfuelling.I couldn't get very good results from the blow-through as it started to miss and not pull cleanly at all.

Could I just have absolutley massive air leaks before the blow through

 

[Fast Guy]

If you attatch the file Ed can download it and look at it (assuming we can attatch files)


I thought the whole point of blow throughs were that they could run if a pipe came off ie big air leak. Unless you meant after the maf?

 

[skiddusmarkus]

Run 1 on draw through

Run 2 on draw through

Run 3 on draw through

Run 1 on blow through

Run 2 on blow through.

It just didn't like to rev on blow through hence the poor results.The injector cycle was at it's highest too on blow through at 84%.

 

[Fast Guy]

Attatch the actual .csv log file rather than pictures. Might need to add the bin file too.

 

[skiddusmarkus]

Can't upload the csv file to photobucket as it doesn't even register the file Carl.I took some videos but they aren't very clear.

 

[Fast Guy]

Can you attatch it on here?

 

[skiddusmarkus]

I dunno, can it host?

 

[Fast Guy]

Well I thought we might be able to, but having had a look it seems very limited unless Steve can alter it. I know you can upload them on the nistune forum, but if you're not a member it doesn't really help.

 

[PobodY]

What about something like mediafire?
Google Docs? - I know that will host spreadsheets, so it should accept .csv files

 

[j0ff]

Email?!

 

[Fusion Ed]

email it to me.