Mass Air Flow wiring problem. Please, please help me solve this

[Fastlife91]

Hi

I am so stressed about this situation and need it resolved, I will try and keep this short as possible


Several months ago Engine light came on reading faulty maf sensor so bought a brand new sensor and put that on.
A few days later engine light back on which read a fault in the maf wiring loom, checked wires and ends were torn so my mechanic friend , Brian, cut ends off.
Car still ran rough with diagnostics and engine light reading maf wiring fault, so Brian said the colors of the wiring looked to be wrong color and in wrong sequence, so as he had some wiring in his garage he decided to have a play changing colors over trying to get it right but just guessing as we could not find color sequence anywhere. he has put connectors on temporarily where he cut the wires to attatch the donor wire to.

Then he decided to take the 6 prong maf sensor off my car and put a 4 prong maf sensor on, he connected 4 of the 6 wires from the maf wiring harness to the replacement 4 prong sensor and put 2 of the wires ( 1 at each end) into a loop saying these 2 were just open loop and not needed, he later cut off the 2 wires, 1 at each end, he said they served no purpose anyway as they are only open loop.

The problem with the maf wiring still persists, not as bad as previously as car not stalling any more but does refuse to accelerate if revved to hard , also if car has been off overnight for example and you press accelerator it tries to stall first time so you take foot off and press gas again and it revs fine.
these symptoms only occurred right after he cut the wires so they are definitely related to the maf wiring being cut.


It has probably been around 6 months now that I have been having these problems with the maf wiring , I did have it booked in with an auto electrician several months back but didn't end up going because my friend told me he knew how to fix it but he didn't and so I feel to awkward to go back to that garage where it was booked in at and I am stuck in same situation.

Anyway he is saying we should put the original 6 prong maf sensor back on and see if that sorts it ( even though only has 4 wires now as he has cut 2 end wires off, 1 at each end , he says that won't matter because they were open loop and not needed anyway)



Any ideas on this situation ?


please help, I am so stressed about it,

Many thanks

 

[HandySparks]

Stop faffing about with amateurs. Take it to a main dealer for the marque in question and get it sorted.

 

[ruston]

Stop faffing about with amateurs. Take it to a main dealer for the marque in question and get it sorted.

Only sensible thing to do now. You do not know what other control parameters he has affected by his actions.

 

[Fastlife91]

Stop faffing about with amateurs. Take it to a main dealer for the marque in question and get it sorted.

I thought my friend knew what he was doing as he is a qualified master technician and he was talking as though he knew how to fix this problem but now it seems not as he has just wasted my time and probably complicated the situation further

I don't want to go to a main dealer as they would probably charge way too much.


How much do you think approximately an average auto electrician would charge to correct this ?


Ty

 

[Fastlife91]

Only sensible thing to do now. You do not know what other control parameters he has affected by his actions.

Hi


Please answer question above that I have also asked handysparks help on

Regards

 

[ruston]

It is a very difficult question to answer.
I would go to a respected Auto Electrician and ask him for an assessment to the degree interference to the original design.
The ECU is dependant on all signals from the various sensors on the vehicle to calculate the correct parameters for correct running of the engine, and some cases the gearbox.
The sensors have a cumulative effect on the ECU and the one that is showing the fault may not necessarily be the one that is.
The two wires he cut will not be there for nothing, unless there is a model variation.

 

[Barry White]

Standard Maf sensors are 3 or 4 wire. The Maf works by using a hot wire resistor as passing air cools this resistor its resistance changes and this is measured by the ECU and gives airflow. The temperature of the air affects the cooling of the resistor too so modern units have a temperature probe installed in the Maf( 6 wire units)

 

[Fastlife91]

It is a very difficult question to answer.
I would go to a respected Auto Electrician and ask him for an assessment to the degree interference to the original design.
The ECU is dependant on all signals from the various sensors on the vehicle to calculate the correct parameters for correct running of the engine, and some cases the gearbox.
The sensors have a cumulative effect on the ECU and the one that is showing the fault may not necessarily be the one that is.
The two wires he cut will not be there for nothing, unless there is a model variation.

Hi, thanks once again for replying.

can you please explain what you mean by '' ask him for an assessment to the degree interference to the original design ''
I am very confused by what that means ?

Is there anything that can be done to replace the 2 wires that he cut off ?


I have had extremely bad luck with cars and l have already spent a lot of money on my current car that I've only owned for about 8 months.


1st car (corsa) head gasket blew 2 months after purchase

second car (astra) head gasket blew several weeks after purchase, after that whole brakes had to be replaced, brake servo, I kept count how much I spent on repairs on that and it came to over £3,500 in 3 years, had to be scrapped in the end.

3rd car- citroen Xsara, Only had this car for 1 month and cost me £700 to buy and spent £200 on other repairs, then had a problem car would not start so after 3 weeks I bought a different car ( now my current car) , I later found out it was the fuel pump had gone on the citroen xsara.

4th car 2006 MK2 Focus 1.8 TDCI Sport , this is the car I have now. Day 1 car overheating loosing water, garage diagnosed head gasket ( but found out later that they lied and only replaced water pump), then a day after purchase light came on dash which later found out was transmission light for gearbox, then had problem with leaking fuel injectors, then turbo was faulty, then all brakes need replacing, shock absorbers replaced, both suspension arms and driver side wheel bearing and more, steering arms, EGR had to be replaced inc manifold which cost me £300, rocker cover leak, and other things too.


I work hard and struggle sometimes to keep my car on the road in a roadworthy condition, I have been lied to about non existing repairs to often and have had very bad luck.

I just want this problem with the maf sorted soon and at a reasonable price



thank you

 

[Fastlife91]

Standard Maf sensors are 3 or 4 wire. The Maf works by using a hot wire resistor as passing air cools this resistor its resistance changes and this is measured by the ECU and gives airflow. The temperature of the air affects the cooling of the resistor too so modern units have a temperature probe installed in the Maf( 6 wire units)

Hi, thank you very much

My car originally had a 6 pin sensor with 6 wires going to it from the harness. then my friend tried swapping the sensor and put on a 4 pin maf and connected 4 wires and looped the other 2, he later cut off the other 2 saying they were not needed.

Now, as this sensor still does not work he says we should put the 6 pin sensor back on and see it it works now that we have swapped the sequence of the color wires around.


Is it going to be a problem do you think that he has cut off the 2 wires that he calls an open loop or is he right that they are not needed?


is there any way to replace the 2 wires that he cut off if needs be that my car may need them ?


Many Thanks

 

[ruston]

Basically , to see if he has butchered the wiring, to be blunt.

I feel sorry for you , this is an all too common story. There are many cars that are passed through auctions etc as trade ins and have multiple problems , then passed on to unsuspecting members of the public.

As you have spent so much on your car it is difficult to let go, so my advice to you is to try and find a REPUTABLE auto electrician and see what needs to be done now.
As you have seen the problems are cumulative , and it is hard to pinpoint a cause on a forum, but abuse and lack of maintenance seems to be a problem with your vehicle.
Is it a high miler.