Faulty Afm?

[Duchie]

Ok ill try and explain it as clear as possible. First of all the problem is on an RB25DE R33 Series 1.

Maybe 1 month ago the problem worsened and the car would cut out and not rev past 2500, would die on idle and sounded like a rotary. So took out the AFM and resoldered the joints inside.

Now the car is drivable, when you first start it, without throttle it will die. Starting with throttle works but for the first 30 seconds if there is no throttle the revs drop below 500 and will die unless you accelerate.

When driving the car it runs fine until about 3k and if you change gears at this point it's fine but if you put your foot flat to the floor the revs climb extremely slow after about the 3k mark and is hence really slow. My point is that the AFM is stuffed or the wiring because the lower revs are fine because its better lean but once it hits the higher revs when its supposed to richen up it doesn't and therefore is really slow. (Incorrect signal from AFM?)

I took the cover off the AFM and with the key switched to on the AFM reading was 0.25v give or take 0.05v. On idle the reading was 1.5volts so only a bit higher than the 1.1v that it should be. When i revved it i didn't see it go past 3volts.

Firstly are these readings acceptable or should i just replace the AFM?

Secondly i tried checking the voltage of the plug to see if this was a problem by measuring the reading of the negative terminal on the AFM plug and the earth of the car and got 0 volts. The manual did not suggest what is right or wrong for this test.

The manual suggested to test the ECCS relay and ECCS loom.

Is the ECCS relay behind the computor(behind passenger kick panel)??

Any help is useful, i want to get it fixed by the end of the holidays so i can drive it to school

[Luciano]

Eliminate the possibilities one at a time. Swap the AFM - if that doesnt solve it, move onto the next item. Check the ECU loom (and even try swapping one) make sure there is no dodgy looking wiring (eg. cut wires with bad connections). I'd also definitely be inspecing coils, plugs, ignitor module, even fuel pump. It is a 17 year old car - maybe even your injectors are worse for wear...

Maybe even try doing a diagnostic / check for error codes

hope you sort it out mate, good luck

[ARTZ]

Have you tried running the car with afm unplugged...

I had a dodgey afm

Mine ran fine with it unplugged but wouldnt idle and sounded like a rotary when it was plugged in...That said i didnt try driving it whilst unplugged but it idled fine..

not really sure why this is but try it...

[Duchie]

Thanks for the suggestions, shold of mentioned but didnt want to ramble... Ive got new superspark ignition coils in the car, i pulled out the injectors and had them cleaned. I did run the car with the AFM unplugged but didnt go for a drive, the thing is the problem is only when driving the car that it doesnt rev freely, when in nuetral its fine.

As for diagnostics check before resoldering the joints it showed error code 12 - AFM and still shows the same thing, i did reset the computor. Ive put different plugs in it recently but i might change em back cause i wasn't too sure about them, im thinking if it's the ignitor then it wouldn't start so i don't think its that but it's just a thought.

I might test the fuel pump too, it does make the buzzing noise when turning the key to on which i dont remember it doing but ive got a poor memory and dont have any cars to compare with.

I dont want to buy a new AFM and it turns out its not that thats the problem, i dont want to waste too much money

[Luciano]

just swap one with someone with a S1 r33, just to test it. they are interchangeable between DE and DET

[-Jimmy-]

I reckon it's your AFM, had the same prob with mine. Even after resoldering the joints.

[Duchie]

Alright thanks for the suggestions, the best option is to replace the AFM because it is 17 years old so hopefully i can get one new for cheap around here. If i still have problems then i'll do the checking of the loom.

[LeCoq]

yes dude!! replace your AFM!!!! u meant to replace those anyways. Its part of major service after 100,000kms im planning to change mine tomorrow coz im having same problem! there only $120 second hand. good luck to both of us!