Sourcing a Mass Airflow sensor
 

As I am encountering problems with my MAF(AFM), was wondering if there are any go to manufacturers for our sensors? Any to stay away from?

I am receiving a loaner soon to make sure it is the sensor and not a wiring problem. Will be checking power and ground to it, as well as checking the signal output voltage tomorrow.

Just wanted to start shopping around soon and being our sensors aren't cheap I want to purchase one that will last.

Scarecrow:
I have had mixed results with "offbrand" MAF sensors for my Jags and Rover. I will always pay the exorbitant OEM brand price in the future.

That's what I was afraid of. I found a used one on eBay "tested and in working condition" for $60. It's being shipped now. Will send the loaner back to its owner when it comes.

Had a chance to test it this morning when I got to work. Getting battery voltage and ground to it. But the signal is sending .09v at whatever range, idle to WOT. No where even close to a volt at idle. Don't really need the loaner now. That AFM is fried.

The car only has 53,500 miles, but the sensor is not original, it's a fuel injection Corp. aftermarket. The guy I bought it from had a few xj6's and I'm pretty sure he switched it out between cars.

Are the genuine sensors a problem child for this vehicle or are they pretty reliable?

Chris,

I assume your OE MAFS is the Lucas LHE 1620 AA if you have the Lucas-Sagem-GEMS Engine Management System (EMS). If so, I don't know of any source other than Jaguar for an OEM unit, and both jaguarclassicparts.com and jaguarmerriamparts.com show that part as discontinued and no longer available (and when last available the "discounted" price was $1,315.03!!!)

RockAuto and Parts Geek are both out of stock on all of their aftermarket options. I just checked everydayxj and growlerparts and no luck there.

This U.K. company claims to have a new (probably aftermarket) unit in stock:

Jaguar X300, XJ6, XJ8, XJS Air Flow Meter LHE1620AA | World Car Parts > Store


And this company claims to be able to repair the Lucas LHE 1620 AA MAFS:

Lucas LHE 1620 AA


As long as working used units are available on eBay for $60 they may be the best option.

Please let us know how it works out.

Cheers,

Don

Would you trust a used one?

Well, the MAFS in most running X300s are used.... :)

In the absence of a reliable source for an affordable new one, a working used one may be the only option. Unfortunately, that is increasingly becoming the state of things for many XJ40/X300/X308 parts.

This.

Looking at the prices of oem sensors makes me cringe. $1400 for a maf is beyond insane. That's a third of what I paid for the car. That being said, I love my car and if push comes to shove I'll try and find the part and pay the price.

Not until I test drive it and test the output signal. How long it will last is a whole other story, only time will tell, and that is assuming it's good.

The tracking says it expected delivery date is Thursday. I'm leaving for New York City Friday and I won't be back till after the new year. If it comes after I leave I won't be able to put it back in until I get back in town. But I will definitely update and let everyone know how it went

Update: I jumped in my car today after work to go home. Nothing but stalling unless I keep my foot on the gas, which also sounds like a idle control valve problem. I'm 100% sure my maf is bad. Hopefully that's the only thing wrong with it. Guess I'll have to wait to put in the replacement to find out. Maybe cleaning the IACV won't hurt either.

The car was running pretty bad for about a week before it finally threw the P0102 code. I cleared it, and even now, the code has yet to reappear. I know our cars are hesitant to throw misfire codes, is that true with other types of codes?

I purchased one of these Air Flow meters (LNA-1620AA) from World car Parts Dec. 2014. Cost with postage here to Australia from the UK was AUD$238, very reasonable I thought & happy with product & service.
Whilst unbranded it appears to be new.
Are you sure that is your problem, I would attempt to narrow it down as much as possible.


John Herbert

I know it is a problem, as to if it is the only problem, I am not sure. It is the only problem which a code was set for which was P0102 Mass Airflow circuit low.Guess I will have to install and find out. (My ultragauge also will not read the g/s airflow, all the screen reads for that is "Err")

I am getting battery voltage and ground to the inner and outer wire (the colors escape me atm but if I remember power was the wire in the connecter closest to the radiator and ground closest to the firewall). And was getting only .09volts out of the middle wire which is the signal output to the computer.

If it's any comfort I just bought a used one in the UK 11 pounds delivered (too cheap to ignore they are usually at least 30 pounds) and it worked fine and tested fine. But it sounds like you want new.

Isn't the MAF output reported very low by the Jaguar OBD or am I getting this muddled with something else?

It ranges from around 1 volt to 5 volts depending on the amount of air passing through the sensor.
Attached is a chart of voltage vs. Kg/s of air

https://cimg0.ibsrv.net/gimg/www.jag...f2ba271f71.gif

Update: I received the used MAF and installed it about an hour ago. Was able too start up and drive the car home with no problems. The car runs way better but I think there is still a little roughness in it. I'm probably just imagining it though. I know it was running pretty rich and the exhaust smelled pretty bad of unburnt fuel. As well as blowing out some black smoke when we tried to get it started yesterday. The spark plugs may be fouled from the excess fuel that's been running through it. I have an extra set of 6 laying in my garage. When I get back in town, I will be tackling my spark plug seals and valve cover gasket. I will check the spark plugs then.

The exhaust does smell better now with the working MAF and no sign of smoke. Also my ultragauge is reporting a much much better short and long term fuel trim.

Here are pictures of the before and after fuel trims reported by the ultra gauge.

https://cimg7.ibsrv.net/gimg/www.jag...b1ce82238e.jpg
Before



https://cimg8.ibsrv.net/gimg/www.jag...99f1afcfc3.jpg
After:<br/><br/>(I got lucky with the short term at zero during the shot, it was trimming between positive and negative)

I found the website for the seller John Herbert was referring to. Will most likely be ordering one soon. Link attached just for future reference.

http://www.worldcarparts.co.uk/Store...1/Default.aspx

Don,
Thank you for the mention.... I have a lot of parts on hand that haven't made it to my site yet. I always encourage people to email for availability.
I have a couple of used MAF sensors for the X300 on hand for less than the $60 ebay price.
It sounds like the issue may be sorted now....

Cheers
David
shop.everydayxj.com

As soon as the cold weather hit here in upstate NY my 2000 xj8 started having problems starting for the first time each day in the morning. It would fire immediately but would not idle high enough to stay running. Engine has never had any starting issues for the 140,000 miles I have put on it over the past 7 years. I installed a MAS that was new, $20 from ebay. Car starts immediately now but does not run quite right -lacks power. MAS air intake temperature reads -40f. Since I know changing the sensor fixed the starting problems I am going to source another brand on ebay. This one is $40. If this doesn't work, then I am going with a new Desno OEM that I found on line for $130

What maintenance can be done to prolong the life of these sensors? I don't like the idea of sending these great cars to the compactor just because one sensor is no longer available.

EZDriver - I have been told that you can clean them with an electronics spray cleaner. I have not had any success with this though. But no worries, I bought a MAS for $100 that worked fine for 5 years. I just replaced it with one that was $40 and the car is working great. I did buy one for $20 that was defective and returned it. If I have further problems I will purchase the OEM Denso unit for $130.

Steve

Do you know of anyone that has used the Denso unit on the X300. This design is totally different. I know Denso has a great reputation and I would think that if they sell it for the X300 that it would work.

I didn't even find a denso unit for our car when I was looking. Still can't find it. Can you post a link? Would be interested.

Chris Sorry it took me so long to post this. I could not find the site. Pretty sure this link is what I found for the OE Denso MAS, but it is $150 not $130. Website is Partsgeek.com

00 2000 Jaguar XJ8 Air Mass Sensor - Air Intake - A1 Cardone, Denso, Pierburg, Spectra Premium - PartsGeek

Here is the link to the Denso MAF sensor. It doesn't use a screen but a probe instead.


http://www.carparts.com/results/?Ntt...ype=global&N=0

The operating principal is the same between the X300 and X308 sensors, but the important thing is the transfer function. That's the relationship between the voltage reported by the meter and the mass of air flowing past the meter. This relationship is hardcoded into the car's ECU, so you would have to match it to the MAF in the airstream to have the car run right.

There is a very important distinction between a mass flow element and a mass flow meter. The picture of the X308 is the element, the X300 is the meter. The element is only half the equation, the tube it fits into is a vital part to the relationship between voltage and air mass (the transfer function). The element and tube are integrated into one part in the X300.

As an example 2005 and later Fords use a slot type meter. The element itself is the same for just about everything from the smallest Focus to the biggest Super Duty truck engine. What changes is the diameter of the tube that the element is put into, and that in turn changes the transfer function that is reported to the ECU. The actual sensing element is the same part though.

The element only senses the small amount of air that passes it. They are quite small sensing areas, about 1/8"x 3/16" and it reads a voltage. However the total amount of air flowing will be very different if the element is in a 50mm dia. tube vs a 90mm diameter tube; it's 3.24X as much air in the bigger tube.

So we would need mass element + calibrated tube + transfer function = mass air meter.

In the X300 the meter is one piece (non interchangeable element), in the X308 the element is replaceable. In the X300 the screen isn't a sensor, it's an airflow straightener; it reduces turbulence and makes the meter more accurate.

Thanks for the good info. That helps. I have seen somewhere where you can get calibrated tube and sensor that will work on the X300. I'll try and find that again and post it.

Sorry for the thread revival, but since this thread is solely about MAF's, I thought it would get more exposure posted here. Ive just replaced my MAF after cleaning had no effect on the hesitation I was experiencing.

I decided to go for a new aftermarket unit from worldcarparts, like another poster on this thread, and am happy to report that the hesitation is gone, and the unit is almost identical to the original, build quality is excellent.

Good find . What is the part # of the Denso insert , not the whole LNA-1620AA unit ?

K & N air filters did a study on the modes of failure of the MAF sensors to dispel the belief that the oil on the filter contaminates the thermistor which is the probe device in the air stream . What they found over hundreds of examples is the silicon used as a manufactures seal off gasses during curing or migrates contaminating the thermistor and on the other side of the seal the electronics signal resolving package . Off the top of my head before looking up the document , most of the sensors failures were because of this . If there was a way to clean the silicone off the thermistor and the electronic package by chemical or mechanical means may negate the need to buy a new MAF sensor . I've been looking for a source of just the thermistor only without the electronics package .

https://www.knfilters.com/maf/MAFTestresults.htm

http://www.sisweb.com/referenc/applnote/app-88.htm



https://www.finishing.com/399/79.shtml

http://www.murata.com/~/media/webren...stor/r03e.ashx

See parts 1 - 4

edited above post

Maf sensor
 

I have just bought a aftermarket one that I tried for diagnostics, but my problem turned out to be ecm so anyone in uk need one I'll sell to them..let me know..its a full unit used for 5 mins...

LHA1620AA for supercharger / LHE1620AA ( Lucas 20 AM or 70390B as marked ) for normal aspirated 4.0 and 3.2. They most likely have 2 different map or maps in the 2 different ECU's and don't pair up . Something to do with the volume related velocity ( higher in SC ) hitting the area of the saturation point in the thermister response curve so there is a difference in the 2 MAF meters .

Still looking for a source for the thermistors if anyone can help break the code and get to possibly a very cheap resolution as the whole meter units disappear .

Figured since I started this thread I'd update my situation. Was running on the used MAF for a while with no problems. Gradually noticed the car feel more peppy and my long term indicated I was running rich at -10.5. Being too lazy to do any diagnosis I threw a Reman MAF from a1cardone I bought off rock auto. I told myself I would buy a new MAF if the used one fixed my problem and never got around to it. Drove for about 20 miles and the long term dropped to about -0.78. Drove another few miles and is currently at 0.00. Car doesn't feel as peppy but I guess it's running the way it was designed.https://cimg2.ibsrv.net/gimg/www.jag...cf0d581cb.jpeghttps://cimg6.ibsrv.net/gimg/www.jag...f4e2b2e2a.jpeg

By way of an additional input on this topic, I recently misdiagnosed my MAF as faulty, and replaced it with a worldcarparts item. No difference from original MAF, and car now running faultlessly with it. Rich running turned out to be due to leak at manifold to downpipe flange.
XJR 6.

My world car parts generic MAF for XJR is also fine, after bout 18-24 months of use

Rose's hesitating on acceleration has been getting worse in the past few days. Was suspecting that the clutch might be slipping (mine is converted manual) but mechanic test-drove it and said it is not the clutch but something like misfiring or a faulty airflow meter. Scanned Rose with IDS and she only threw one code P1137 - Lack of heated oxygen sensor switch, sensor indicates lean bank 1. Re-oriented the O2 sensors with IDS's programme and cleared the code which does not return any more. But car still hesitated when stepping on the accelerator and this happened at all speed and gears. I have a full set of Japan-made coils which I may try on, but I too suspected that it is more likely to be air flow meter. Checked the specs on mine and it is LHE1620AA, manufacture date S1/05, so presumably more than 13 years' old. So I recalled there is this thread about alternative source of the air flow meter. Unfortunately a quick web search showed that even generic airflow meter previously sold by WorldCarParts is all sold out. The only solution now is to buy one re-manufactured. Buying one used seems risky as even my own is 18 years old. Wonder if folks have any late discovery of other aftermarket product that would do the job without breaking the bank.

Sounds like your O2 sensor is bad, not the MAF. Reorienting won't fix that; the purpose of reorienting was to correct the ECU if the O2 sensors were plugged in backwards, i.e. the upstream connector was plugged into the downstream socket. Reorienting flips the place the ECU looks for that particular O2 sensor.

I would start by replacing the O2 sensors and go from there. I'd use the NTK 25018, that's the OEM sensor. It's also smaller than most, and depending on which one it is, space can be at a premium.

The O2 sensors were replaced only a few months ago. It is the first time the code has arisen but it has not come back after clearing it. Anyhow, would still want to find an airflow meter just in case, particularly when it is now as rare as gold.

If you're getting a lean code it could also be a leaking exhaust manifold to downpipe seal, or a cracked manifold itself. Those are quite common.

I have stainless steel exhaust manifolds installed, so no cracks; but there maybe exhaust leak down at the joining points where the exhaust manifolds meet the downpipes due to poor workmanship, but Rose has been running very well with a mild leak. Will take a look from the bottom to see if leak has worsen.

Hi Qvhk. I noticed your post and thought I'd mention the fact that I have the old AFM from my 3.2 donor car. I don't know how good or bad it is but it worked fine when the donor car was running. If you're interested, you're welcome to it if you're happy to cover postage, you know, the usual procedure. Let me know and I'll dig it out and get the part number off it.

All the best!

Rose has been stranded pending a thorough check of exhaust leak. I can too replace the coils to see if that would cure the problem, but I still suspect that it is the airflow meter, and in any case would want to have a spare available if money can still buy me a new one. I sent a message to WorldCarParts through eBay and got a reply saying new stock will be available in 2-3 months time. Not sure if more enquiries will help speed up the stock replenishment. Have found a few refurished airflow meters online, for about the same or more money.

Many thanks. I just checked. According to JaguarClassicParts.com the XJR uses LNA1620AA, whereas the 4.0 NA and 3.2 uses LHE1620AA. So the 3.2's version would not fit my XJR. Just found that WorldCarParts has both offerings, i.e. LHE1620AA and LNA1620AA, but both are out of stock. Wonder how are they different. I found a shop online that claims to be able to remanufacture car ECUs, airflow meters, and practicaly any car electronics, so I wonder if it is worth a try.

Hi Marcus,
It is absolutely essential that you fit LNA1620AA not LHE1620AA to a supercharged engine. The relationship between airflow and voltage output is completely different for these to airflow meters. A supercharged engine will be massively over-fuelled if it is fitted with LHE1620AA.