Checking and cleaning MAF sensors

[fullbost]

Tony when checking the maf sensor voltage you state there shoild be battery voltage on the white wire theb you said something about 5v which i dont understand could you please enlighten me

[fat paddy]

OK.........here is my latest two cents worth.
I have cleaned the sensor in the past and know how ugly it can get with out a clean and how nice the vehicle runs after. Since then I have fitted a catch can. I have since done about 20-40 thou kms. I pulled the sensor out tonight to clean it but bugger me it is still as clean as. The Catch can is working beautifully. I will clean the sensor all the same just to make sure.
Next job is to fit the EGT and boost guages.
I bought a EGT from Autob.... and matching boost guage. The EGT was $180. Opened it on Father's Day to find no probe included. Sent the good wife back to enquire and the said shop ordered the replacement probe in. She picked it up today after handing over $100 more only to find more parts missing from the probe ie the nuts and olive (?). Brand = AutoMeter model 3343, its made in the USA so I was hoping for something with a bit of quality. My question is should the probe have been in the box in the first place and has my wife been ripped off.

[claw45]

G/Day Tony, Have Passed my GU 03 3.0 di TD over to my son -- spoke to him today -- advising what a great site this is & he says his rig is feeling a bit flat ( 119k -- no issues ) so suggested he clean MAF sensor & complete the " insurance pack" -- would the correct steps be ( after clean sensor )
# 1 --fit boost & e t g gauges
# 2 --- fit blank off plate on emission port
#3 -- fit oil trap
He is electrical fitter so should be ok with testing -- how complex is gauge fitting -- is there much stripping down to get the gauge locations
correct ( welding /brazing ok) Thanks in advance Jim.

[Jamie]

You mention a power loss? I went away this weekend and had a similar issue when driving back from Colac. After about 2 hours I began to struggle to get over 90 when towing a camper van. Is this what you've experienced. Mines a 4.5L dual fuel. Could the sensor be causing this?

[YNOT]

You mention a power loss? I went away this weekend and had a similar issue when driving back from Colac. After about 2 hours I began to struggle to get over 90 when towing a camper van. Is this what you've experienced. Mines a 4.5L dual fuel. Could the sensor be causing this?

Possibly but I'd be doing a code test first. Did it happen on both fuels?

Tony

[Jamie]

Running like grap on Petrol at the moment anyway, but yes it did happen on both fuels. What do you mean be a code test? Excuse my ignorance.

[YNOT]

Running like grap on Petrol at the moment anyway, but yes it did happen on both fuels. What do you mean be a code test? Excuse my ignorance.

EFI vehicles have the ability to identify faults within the engine management system and store fault codes relating to them. Retriving/reading fault codes can give you a clue as to where to start looking for the cause of the fault. Fault codes rarely tell you exactly what is wrong or what component to replace, ie. just because a code might say "exhaust gas oxygen sensor out of range" doesn't mean the EGO sensor is faulty, the fault may be something as simple as a leaking inlet manifold gasket.

Check this thread about reading fault codes; http://www.nissanpatrol.com.au/forum...eading+erasing

Remember with ANY engine diagnostics, CHECK THE BASICS FIRST.

Tony

[Jamie]

Thanks Tony, your post is really informative and easy enough a novice like myself should be able to follow.

[myzathreeby]

Hi YNOT
Just a question.. What is the mass air sensor actually detecting?
and what is it controlling.
Why would it affect the engine power.
I am assuming you only get the MAF sensor on the 3.0 turbo so I'm guessing it has something to do with a fault on the turbo or blocked filter. which causes a loss of power.
Cheers John

[Robo]

MAF or AFM = mass air flow metre, or air flow metre.
sends signal to computer of actual airflow volume being ingested for the computer to determine fuel volume in relative time etc.
so if it's dirty or faulty incorrect info received by ECM and you have problems.
ECM= engine control module, "computer".
Only answered for Tony as I recon he's a very busy man.
Cheers