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2001 Nissan maxima crank ref sensor corrosion on tip with rich condition
Hi Ben, I cleaned the Maf and ran a scope on the and the response was smooth from 1.2 V at idle to 4.1 volts on wide open throttle. I checked on the scan tool only at idle earlier and that was 4.3 g/s and when I rev from idle which is 675rpm to 4500 rpm it ranges from 2.2g/s to 16.9g/s. and shows a smooth graph. I have a Delphi scan tool 150ds. Can you work with this data or do you need more. By the way I scoped my upstream o2 sensors and they are switching 3 times in 10 secs.
It has a 2.0 litre V6 engine European model Maxima QX. The 4.3g/s is only since I cleaned it previous to that it was 2.2 - 2.6 g/s so cleaning may have made things worse or just made it honest. The problem with trims is only at idle because when rpms are above 1200 they float either side of 0 from apx (+/-) 0.8% to 3.2% and climb gradually all of these numbers are not under load. I am only using trims as a reference so the fact they improve with rpm makes me think the MAF might be bad. I might add the car is responsive but I can hear a slight miss, still its better than it was but she is a bit shuddery at idle. I can't see voltage when I drive her because my scan tool doesn't support it just g/s and my scope is laptop based and the cables are too short to reach the cabin. I will try and get better readings today. Thanks again
Hi Ben I went for a drive and went through the gears from idle she ranges from 3.1g/s @ 0% throttle and up to 48.9g/s @ 68% throttle in third and approximately 4300rpm,
Well that doesn't seem good to me a 2.p engine should idle at about 2 grams +-.8 and at 100% throttle under load (accelerating) you should be able to reach at least 80 grams . How did you clean it?
Hi Ben, I used electrical contact cleaner but I think it just highlighted the problem. I cant get MAF cleaner anywhere local by local I mean 30 mile radius. I noticed on a section of the MAF there is a rectangular polished plate which looks like it has a small amount of corrosion either side of it. I think I need to replace the MAF. I will have to try and ship one from rock auto which will take over a month with customs but there is a difference of 200 euro and its the OEM Hitachi so worth waiting for. Is there anything else I can do to confirm, or do the numbers speak for themselves. Dar
If badly fouled some types of MAF sensor don't return to within spec after cleaning, I mainly see Bosch analogue sensors on BMW diesels and have rarely had any luck cleaning them. The other ones I see are Fords and cleaning them often works.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
Hi Ben Nissan use a Bosch sensor on the primera diesel here which is the same model as the g35 in the states which is the same type of sensor which don't clean well either, I guess I am buying a MAF thanks again for all your help When I change it out I will post back with the result hopefully it will be good news because I am out of Ideas if not.
hi Ben tried new maf now its opposite positive trims at idle and -10.2 lt at 2500rpm+
I presume this means new MAF must be faulty. I am going to run it through a test with the original MAF to see what HC'S and CO levels really are will let you know.
