M.A.F sensor for 1993 Maverick 2.4i

[Muckypup]

Now now boys, enough with the automotive porn...

Yes i'm jealous, the 2.7 diesel has a turbo and a maf sensor you can buy off ebay for pennies... I just have a flat four pot farty gas guzzler But I bet its probably cleaner than all shown (tarmac fairy) :augie

I have ordered a second hand maf sensor from a breaker for £20. The price does not fill me with confidence but worth a punt i thought.
I have not removed mine and tried cleaning it as yet nor have I disconnected it. I have no experience with such parts so was going to wait whilst I received the replacement, clean it up then swap and see what happens.

What happens if you disconnect it? Would the engine run un-restricted? Is there a chance it may run better disconnected?
I know nothing, i'm from Barcelona... :nenau

 

[lacroupade]

Now now boys, enough with the automotive porn...

Yes i'm jealous, the 2.7 diesel has a turbo and a maf sensor you can buy off ebay for pennies... I just have a flat four pot farty gas guzzler But I bet its probably cleaner than all shown (tarmac fairy) :augie

I have ordered a second hand maf sensor from a breaker for £20. The price does not fill me with confidence but worth a punt i thought.
I have not removed mine and tried cleaning it as yet nor have I disconnected it. I have no experience with such parts so was going to wait whilst I received the replacement, clean it up then swap and see what happens.

What happens if you disconnect it? Would the engine run un-restricted? Is there a chance it may run better disconnected?
I know nothing, i'm from Barcelona... :nenau

The point of the MAF is to feed information to the ECU about the volume of air entering the engine (or more accurately the amount of O2, which varies with temperature not just volume) so that it can adjust fuel flow to suit....eg cold day = more oxygen as air is denser, so more fuel....


And T2 MAFs pennies? I wish! The Hitachi is around £400 in the stealers so buying s/h makes a lot of sense.

 

[Muckypup]

£400 seems a lot???
Seen loads of these on ebay... http://cgi.ebay.co.uk/NEW-NISSAN-AI...arts_Vehicles_CarParts_SM&hash=item45f29a1c5f

Really does seem like pennies compared to the £998.75 I would have to pay Nissan for one for my 2.4i :doh

I just hope I can find a second hand one that cures my issue.

I am also starting to get very suspicious of my thermostat. I know it is not working properly and need to save up for a new rad before I change it
If the MAF sensor can be controlled by temp I suspect if neither MAF and stat are working properly they would be confusing hell out of each other and causing all sorts of issues????
Any experts able to advise on this?
I believe the engines are supposed to run around 90 degrees but mine only gets to around 70 degrees at most

 

[spiderpig37]

i have just ordered a bosch one for my 2000 model £68 from nissan main dealers pick it up tomorrow seems a big difference
cheers

 

[Muckypup]

Wish it was so simple for the petrol model

 

[lacroupade]

£400 seems a lot???
Seen loads of these on ebay... http://cgi.ebay.co.uk/NEW-NISSAN-AI...arts_Vehicles_CarParts_SM&hash=item45f29a1c5f

Really does seem like pennies compared to the £998.75 I would have to pay Nissan for one for my 2.4i :doh

I just hope I can find a second hand one that cures my issue.

I am also starting to get very suspicious of my thermostat. I know it is not working properly and need to save up for a new rad before I change it
If the MAF sensor can be controlled by temp I suspect if neither MAF and stat are working properly they would be confusing hell out of each other and causing all sorts of issues????
Any experts able to advise on this?
I believe the engines are supposed to run around 90 degrees but mine only gets to around 70 degrees at most

The one you linked to is (i) a generic MAF from who knows where....so you can hope it will work but..., and (ii) its a Bosch replacement. The Hitachi is mega expensive but almost never fails, the Bosch cheap but fails often....but the two are not interchangeable unfortunately.

Re your stat, why aren't you changing it now? Its cheap as chips and nowt to to with replacing the rad....?

And you need to understand how the MAF and the stat work. They are very different and only one plays any direct part in informing the ECU - they certainly don't react to each other.

The stat is purely thermo-mechanical and binary in operation, i.e. its on or off at the appropriate temperature. It doesn't send signals anywhere and it has no electrical contacts. However, the engine temperature it influences is measured elsewhere in the system so it does indirectly have an input to the ECU if you like. So my advice would be, change it ASAP. It can only improve matters - especially as its clear things aren't right in that dept.

The MAF does however have direct connections to the ECU and therefore helps to manage fuel flow in accordance with the amount of O2 going into the engine.

Its simple in operation - just a heated wire, the temperature and therefore resistance of which changes with airflow....and the colder the airflow detected, the more fuel the ECU allows in, because colder air is denser, so has more O2, so can burn more fuel.

GIven the price quoted to you for a new one - which might include throttle body and all sorts, its best to go the scrapper route. Nothing to lose really.

 

[Muckypup]

The one you linked to is (i) a generic MAF from who knows where....so you can hope it will work but..., and (ii) its a Bosch replacement. The Hitachi is mega expensive but almost never fails, the Bosch cheap but fails often....but the two are not interchangeable unfortunately.

Re your stat, why aren't you changing it now? Its cheap as chips and nowt to to with replacing the rad....?

And you need to understand how the MAF and the stat work. They are very different and only one plays any direct part in informing the ECU - they certainly don't react to each other.

The stat is purely thermo-mechanical and binary in operation, i.e. its on or off at the appropriate temperature. It doesn't send signals anywhere and it has no electrical contacts. However, the engine temperature it influences is measured elsewhere in the system so it does indirectly have an input to the ECU if you like. So my advice would be, change it ASAP. It can only improve matters - especially as its clear things aren't right in that dept.

The MAF does however have direct connections to the ECU and therefore helps to manage fuel flow in accordance with the amount of O2 going into the engine.

Its simple in operation - just a heated wire, the temperature and therefore resistance of which changes with airflow....and the colder the airflow detected, the more fuel the ECU allows in, because colder air is denser, so has more O2, so can burn more fuel.

GIven the price quoted to you for a new one - which might include throttle body and all sorts, its best to go the scrapper route. Nothing to lose really.

Thanks for the advise :thumb2

The problem is my rad is dropping in bits and slightly seeping around the seals anyway. To get at the thermostat I need to remove the rad really so if its coming off its gotta be replaced. Or I fear if I changed the stat without doing the rad then the increase in water temp will create higher pressure in the system causing the seeping edges to turn into full blown leaks, resulting in a rad change anyway.

I've got a second hand MAF sensor on its way to me (apparently) can I service it in any way to help make sure it works?

 

[lacroupade]

Thanks for the advise :thumb2

The problem is my rad is dropping in bits and slightly seeping around the seals anyway. To get at the thermostat I need to remove the rad really so if its coming off its gotta be replaced. Or I fear if I changed the stat without doing the rad then the increase in water temp will create higher pressure in the system causing the seeping edges to turn into full blown leaks, resulting in a rad change anyway.

I've got a second hand MAF sensor on its way to me (apparently) can I service it in any way to help make sure it works?

I keep forgetting yours is a petrol; setup must be a bit different because on the diesel the stat is entirely separate. But valid point about extra strain when the water is circulating properly.

Personally I'd just stick the MAF on and try it first. Worst case just spray the wire liberally with carb cleaner and let it drain/dry naturally. Most people that complain of failure have been poking theirs with cotton buds, screwdrivers and all sorts.....!!:doh

 

[solarman216]

Hi just been out and looked at my MAF sensor it is the Hitachi one with three wires A B C, it has two fillaments and whilst they are quite robust (they are wound on formers) I would not be touching them with anything, mine was quite dirty such that I could not see the wires on the intake side, so I put som petrol in a dish about 50 mm deep and washed it of by moving it back and forth through the petrol, few seconds, clean as a whistle with no chance of contamination, OK now to test it, clearly there are some electronics in the plastic encapsulation, so really meaningfull testing is not possible, but the two fillaments read approx 20 ohms, so they are OK and the most likely part to fail I would think, now for the connections, Ok this can be difficult to specify but here goes, using a good digital test meter set on Diode test, with +- being the polarity of the test leads, I got these readings, (AB) A+ B- 1.5; A- B+ 0.5; (BC) B+ C- 1.06; B- C+ 1.66; (AC) A+ C- 1.78 A- C+ 1.13; these readings may vary from meter to meter but not by a significant amount, hope this helps, Rick

 

[lacroupade]

Hi just been out and looked at my MAF sensor it is the Hitachi one with three wires A B C, it has two fillaments and whilst they are quite robust (they are wound on formers) I would not be touching them with anything, mine was quite dirty such that I could not see the wires on the intake side, so I put som petrol in a dish about 50 mm deep and washed it of by moving it back and forth through the petrol, few seconds, clean as a whistle with no chance of contamination, OK now to test it, clearly there are some electronics in the plastic encapsulation, so really meaningfull testing is not possible, but the two fillaments read approx 20 ohms, so they are OK and the most likely part to fail I would think, now for the connections, Ok this can be difficult to specify but here goes, using a good digital test meter set on Diode test, with +- being the polarity of the test leads, I got these readings, (AB) A+ B- 1.5; A- B+ 0.5; (BC) B+ C- 1.06; B- C+ 1.66; (AC) A+ C- 1.78 A- C+ 1.13; these readings may vary from meter to meter but not by a significant amount, hope this helps, Rick

There are some recommended readings in the manual I think Rick....and remember the Hitachi (which is mucho reliable and expensive) is wired differently to the Bosch which isn't either of those things :doh) - the two aren't interchangeable....but you are right, its usually just a bit of shite on the wire that changes the resistance and buggers things up - petrol or carb cleaner and non-contact are admirable fixes!

 

[solarman216]

Just tested another one and got the same readings, this one came off of the broken throttle body of the used engine I put in a while ago, having said that I have just swapped them over on the car and I think it sounds better and is idling better, now this may just be because I have cleaned them both, I will drive it for a few days and swap them back again and see what the results are, watch this space, Rick

 

[lacroupade]

Just tested another one and got the same readings, this one came off of the broken throttle body of the used engine I put in a while ago, having said that I have just swapped them over on the car and I think it sounds better and is idling better, now this may just be because I have cleaned them both, I will drive it for a few days and swap them back again and see what the results are, watch this space, Rick

And the performance will improve with time as the ECU relearns to cope with the new inputs.....:thumb2

 

[Muckypup]

Thanks again for the info guys! :thumb2

The ones you are talking about Rick, are they off a petrol or diesel model?

The reason I ask is because the MAF sensors appear to be completely different parts on both engines. Diesel being a round job that fits in the air pipe, the petrol version being a little square thing that bolts to the side of the throttle body. I'm just wondering if they same will apply to both parts or not

 

[solarman216]

The units I have tested are from a 2.4 petrol on the throttle body, Rick

 

[Muckypup]

The units I have tested are from a 2.4 petrol on the throttle body, Rick

Excellent, just need to wait for my used jobby to arrive EVENTUALLY lol and I will follow your advise :thumb2 :thumb2 :thumb2