Thanks ScannerDanner - My '89 Ranger 2.3 with 135k restoration project stalled because I couldnt find the problem. Replaced MAF and solenoid a week ago and stalling and hesitation persisted. Dangerous for driving. I put in o2 sensor cause it was totally clogged. Better, but still bad. Did what you said and disconnected MAF and turned ignition on off on off. Wow, runs great! The aftermarket MAF is crap. Will be putting in a Motorcraft MAF tomorrow and I think the problem is solved.
Great video Paul! i noticed that with the MAF plugged in, Both PID's for Pulse width were over 40ms!! And with it unplugged, around the 2ms mark!! Very cool stuff!!
Great video. I agree with the grams/second approximate correlation to engine size in liters. This is what I was taught and have observed. However, it is an approximation. As you are no doubt aware, the speed of the PIDs could be increased if you would have gone into a custom setup and limited their number (as we should remember, the PIDs are pushed out by the PCM in series, i.e., sequentially, and repeated over and over).
I used shop rags for my face until I used one that had a long steel wire in it from a machine shop and pierced my eye with it. That's when I went to the blue shop towels .
Really enjoyed this video, My 98 2.5l ranger has a 0.50 g/s with and without the MAF connected. This is the second time ive had a bad MAF sensor, my first one I broke and this second one lasted me a month before it went.
I don't normally do this. I believe live troubleshooting and hearing the thought process is just as if not more valuable than a video created where one already knows the problem. But both versions have value for sure.
Always glad to see you, you are the man! Love you like a bro, respect you like a master. I am studying diesel engines now, but none of the teachers are as good as you, i'm missing your capacity of making student understand, i'm missing you. By the way italian mechanics eyes pops out when they see your book, at least the lazybones :) God bless
Thanks brother! Wish I could take the diesel classes with you. That would be cool. Remember so much of what we do in the automotive field transfers directly over to diesels. You'll do great I'm sure of it.
Danner, you should try doing Blink 182 cover songs if you ever get bored with wrenching. You have the voice/accent for it. Haha. Keep the videos coming. Love your work.
From what I've heard the grams per second should be roughly the size of the engine at idle and about 40x the engine size at w.o.t. (4 liter engine around 4 g/ps idle and around 160 g/ps at w.o.t). I'm pretty sure these numbers will not work with turbo or supercharged engines though.
7:19 My guess It's adding fuel because the MAF gm/S is telling the car it's flying Harry Potter style with no speed or other input feedback. Dumping fuel to try to keep the engine running but it's just pegged max rich. It's got a baro MAP backup according to the PIDs (you show baro). The question is why can't it tell that the MAF is lying using the O2, MAP, TPS, IAT, and other inputs? Ahh because it's in open loop strategy. Think you just answered your own question.
***** the BARO PIDs are actually calculated off of the MAF, no MAP on this design. It is goofy that Ford still reports this as a frequency number. (left over software from MAP engines no doubt)
Can you have any information if you checking maf sensor with ordinary multimeter? Finding problems when you measure wires and connections only with meter?:)
Hey man love your videos. My 98 explorer has been having a stalling/shaking issue at idle. When i'm sitting at a long light or a drive thru i notice my RPMs dropping to the point that the car shakes and the lights dim. SOmetimes i have to put it in park just so it doesnt completely stall out. It stalled on a red light today. I ran seafoam a few days ago and the problem was gone for a couple days. The RPM needle was steady as ever! Thought it was fixed. But issue came back today. Replaced PCV,IAC,upper and lowe rmanifold gaskets. Cleaned Throttle body to new condition, cleaned MAF several times, new air filter, fuel filter is a year old. Doing a coolant change tomorrow since its been 60k miles since ive owned the car and i've never done it. ONe more tidbit of info is on FORSCAN i have a CASE GROUND reading of -0.15. This matches the multimeter reading from my negative terminal to the case of the alternator. I know its supposed to be .05 or less. Could a bad ground be causing all these issues? Thanks if you read this. Oh btw no codes.
I'm fine with that case ground reading. How does it run when your on the throttle? Have you done a compression test? What are your fuel trim numbers at idle?
Long Trim 1 = -7.42 Long Trim 2 = -3.91 Short Trim 1= Bouncing from -.42 to 1.96 seems to be bouncing all over Short trim 2 = -0.23 to 2.80 also bouncing around a lot. FUel pulse width 1 = 2.4ms Fuel pulse width 2 = 3.12ms Is the short trim supposed to be doing that? Car runs great when not in idle. Never stalled out of nowhere and starts up every time at cold start or after it stalls. I'll add that my catalytic converter is rattling at idle as well. They are almost 20 years old at this point. COuld that cause the stalling?
My 98 mountaineer keeps throwing p0102 cleaned maf replaced maf no matter what I do I read 1.8 to 2.6 g/s and it jumps between the two at idle and stays at 1.8 when I throttle up
Very good info about the mass flow sensor but the fact is you should have replaced it to prove and to see by the scan tool how a mass airflow sensor works...
I try to show the replacement whenever possible but I did prove the fault without showing the new MAF. The bad MAF had good signals at times. Same thing the new one would have shown.
Scanner Danner got a question bud..... i have a ford mustang gt and I have a misfire I've replaced plugs and coils and every normal thing you'd try..... I took it to ford and they said my maf is out of range its suppose to be 156 hz and it's running like 148 or 149...... is that enough to cause running issues?
I got a 98 Ford Explorer. I have engine codes on the other side of the spectrum. I got lean codes on bank 1 and bank 2. Thoughts? 02 sensors? MAF sensor? ECM? Fuel injectors?
+shawn sharpe Thank you! For my Premium channel you can use a VPN to mask your countries origins. This is allowing others to access the content. I hope that helps.
Hey Dan, only just discovered you in the last week or so. Can you ship your book to Australia and can I pay the fee for premium or is it US only? Thanks for your vids. Always learning.
Yes we can ship to Australia but shipping costs may be a deal breaker. Aeswave.com is the company who handles my paperback sales. You'll need to check with them for a price. Also my premium channel is available in Australia. Thank you! Let me know if you have any other questions.
Not ashamed to admit... This is (Over My-Underneath The Shade Trees Head)!!! Did Learn Something Though... 🙄😂😂😂👍 System Default you talked about was something I’d never heard of... Plus i need to get this running (Rich) problem Fixed SAP or plan on spending $$$ for clogged catz... Plus a Good Place to hook my Vacuum Tester!!! And as always... Use Common Sense!!! Which mine is telling me After a couple more test-Get my REAL MECHANIC BUDDY TO COME LOOK AT THIS 02 Ranger 😂 Thanks For the Video!!! 👍
I have a Fiesta SE 2012 1.6. The MAF conector got smashed, and i bought another conector, but i need the diagram of the wires. The wires are almost of the same color. I need to test with a scope before to make sure. Where i got that info? MAF: 3L3A-12B579-BA 6 pin conector. I'm from Brazil, its not easy to get this info here :(
Neat trick on the rev limiter to stop injection pulse to drive the 02's lean. Nice short cut to the back pressure test as well. So the MAF sensor is reporting more air to the ECM than is actually coming into the engine causing the ECM to drive the mixture richer?
also i have been seeing some start stall issues and it was maf problem too. i have had good luck with engine size being close to g/s, but it is way off on smaller engines like 3.0l and smaller. (its just a ball park number anyway) i mostly use load values and max g/s to condem maf. thats if it runs good enough...
Have you ever had a MAF issue only affect one bank? Have an 08 f150 with a 4.6L in the shop that has p0174, misfires on 3 of the bank 2 cylinders and a p0316. Noticed the p0316 could be faulty crank sensor so I tested with a scope and it showed excessive air gap. Pulled it and the magnet was gone. Swapped and still have the same issue. LTFT is about 30 on bank 2 and roughly 8 bank 1.
ScannerDanner I was leaning towards timing next. For some reason I wasn't even thinking about exhaust restrictions. Its not really a low power situation though. Just a rough idle. Kinda smooths out at cruising speeds.
ScannerDanner not entirely sure. The guy came to pick it up the same day I changed the sensors. I told him I needed to perform further diagnosis and he said he would bring it back. Pulled fuel trim before he left and seen bank 2 was still very lean at about +30 and there were multiple misfires on bank 2.
MAF ECM Ground wire makes clicking sound when I tested the wire number 2 of 4 w key on w 0v. But also reads 12 volts on a multimeter before I even turned the key on why would this be on a MAF ECM Ground? Please help
@@ScannerDanner yes I looked at a wiring diagram it made like a short circuit type clicking noise I've even had the test light flicker unstable on the fuse that controls the MAF, in process my battery died while testing the vehicle. I was at my witts on this one so I turned it over to a Mechanic Shop to see if they can figure it out... With a new battery
I have a 2005 Mazda Tribute 3.0 with 162000 miles. It runs great. The problem I'm having is that I get different miles per gallon for every tank full. On one tank full I will get 19 MPG, then the next I will get 15 MPG, then 13 MPG, Then 10 MPG, then 15 MPG, Then 19 MPG, and so on. Originally I used to get 20 miles per gallon. I have replaced the spark plugs, spark plug wires/coils, and every filter I can think of. I’m the type of driver that does not have a heavy foot. What is weird about this issue is that the gas mileage fluctuates so much. Could this sensor be the problem?
, can you recommend a scan tool like Auto tap or enginenuity for 1988 Ford Econoline OBD1 can't seem to find them. Low dollar medium price high dollar choices recommended. Thanks love to all Jeff
hey scannerdanner. how reliable is a sweep test for a MAF sensor? I did a sweep test with a pico and I didn't get that inital spike. Could this mean that the unit needs to be replaced?
Echowhiskey the initial spike has a lot to do with operator error. If you do not let the idle come all the way back down (empty the manifold of psi) and then also if you do not rapidly snap it, you will not see the spikes I've shown in my book. Other than that, a drive by wire system may give you problems, then contaminants on the hot wire for sure.
The signal of MAF on my ford Windstar 1999 reads 1.6 on idle and decreases on acceleration. These are opposite readings to what I learned from your videos. Please help. The car is working fine.
@@ScannerDanner Maybe he or she has a clogged exhaust.Only a clogged in my opinion would cause a decrease in maf voltage as there will be less airflow into the engine due to an increase of exhaust backpressure. I may be wrong.
Load pid was screaming maf issue, it showed 100% at idle, you should look into that pid it is my go to for suspect mafs especially on fords, and Toyota
That load PID also showed 100% load with the key on. Also it is a processed calculation. Did you see it with the MAF unplugged? Guess I don't use it enough to trust it. What other variables can cause a higher than normal load PID? Thanks Michael!
ScannerDanner Albin Moore taught me the method, yes it is processed data, but it's main input on most systems is MAF, and throttle angle. So on a ford if on a full throttle pull it should hit 90 +%, if it is in the low 80s or below and no issues with the TP sensor you are done it either needs to be cleaned or replaced. Toyota the load will not go as high so high 80s to low 90s any lower and also done misreporting MAF
ScannerDanner I have a 2001 ford Taurus. And it James into rev and drive hard and keeps breaking my mounts.can you help and tell me what the hell is wrong
Got a Ford 3.0 shows 30% load at idle and that was with the serpentine belt off due to a locked up ac pulley. I'm thinking that is a little high and suspecting maf sensor issue. Sound about right? -10% fuel trims at idle as well.
good video but just a quick point, avoid having a oily rag in the trouser pocket as it has been linked to testicular cancer due to oils being carciogenic, cant be too careful.
ScannerDanner Premium I was taught this during my apprenticeship, I'm not too sure about the scientific/medical facts but its always something I adhere to, prevention is far better than cure in all cases.
Thanks for this video! My 2003 Ford Escape 3.0 (AJ engine) has a bad fuel milege. I tested my MAF sensor as you showed, but i have 6 wires on it. As i understood 1st and 6th (E and F letter) wires go to temperature sensor inside the MAF body. I tested 12volt supply and both grounds, everything is ok. Then I connected red wire of my multimeter to 5th (D) wire and black to negative contact of the battery. When i put the key to ON position, multimeter shows 0.07 volts. When i strted the engine, multimeter showed 1.15 volts and after engine got a work temperature multimeter showed 0.76 volts. Does it mean that my MAF sensor is bad? Everybody says that when the voltage more than 1.03, MAF sensor is bad, but nobody says what if the voltage less than 0.9. Sorry for my English!
It is becoming more and more difficult to answer questions here. I have 80,000 people asking me for help now. So I have created a forum to help you guys better. It is free to join and we can exchange pictures, wiring diagrams and waveforms if needed to help guide you through the process of troubleshooting your vehicle. Thank you so much! Hope to see you there. Paul Danner (ScannerDanner) www.scannerdanner.com/forum/post-your-repair-questions-here.html
Not necessarily. But if the computer is not receiving reliable data, it cannot compute reliable values for/from the other input that is gathered and used to compute what changes to make and how to manage the engine. That translates into... it will still run, but it will probably run like crap and do unpredictable things.
Hey my 05 mustang gt doesnt have a check engine light but im suspecting a bad maf.. I have rough idle here n there but under load theres a lag in accelerates. When taking off from a stop it feels like it wants to stall and engaging the clut h is a drag any thoughts?
@@ScannerDanner ok i will thanks! and would a faulty maf cause the drivability issue i have where as im engaging the clutch taking off in first gear it almost feels lke the idle drops or it wants to bogg down? Once its running it feels sluggish and if i punch it hesitates but eventually it picks up. Sometimes when i start the car i can sorta smell gas. No leaks tho..
I Just bought a 94 ranger 3.0 liter 56k original miles on it has no power and has a mis I replaced the fuel pump & filter New plugs wires rotor & cap ,Now on the coil there looks to me like a little silver I don't what its called it looks like a condenser on an older motor with points but there are no wires on it they were cut or broke off and there is a wire coming out of the coil Harness with a connector after the connector the wire is cut off and I dont know where it supposed to go could this be my problem with no power and a mis
@@ScannerDanner :o! oh dear lord jeezus I damn near fainted when I read that, uhmm.. well do you happen to know of a cheaper alternative that can let us view live voltages and data like those tools can?
I think with the newer 8 wire is almost twice the liter and the older ones its 1 per liter . which is not scientific but I think it gets you in the ball park. I don't have any hands on confirmation , I just have been told that it is quite different
Question, trying to fix Brother in laws 1996 f150 4.9 the MAF live data reads 0.10 with key on engine off. It reads the same with the MAF unplugged or plugged. Pretty sure it's a bad ECM. I've checked multiple vehicles with my scanner and all of them read 0.00 live data with engine off. I've checked all fuses and relays aswell not sure what else could cause this except maybe a bad ground although the ground wires seem good. Your thoughts? Any help would be appreciated. Thanks
with the key on engine off, take a test light (incandescent) connected to battery positive and touch on the MAF signal wire (sensor MUST be plugged in to maintain the PCM ground for the MAF circuit) and see if the MAF signal on the scan tool jumps to 5v. If it does, your signal wire and PCM/ECM are fine. Tell me what you see
@@ScannerDanner forgot to mention its a regular hand held scanner Zurich ZR15 reads live data 0.10 (lb/min) with or without the mass flow sensor plugged in engine off key. I don't think this scanner reads Voltage? The live graph does show it jumping like a heart rate monitor with key on engine off. I did try it though and the prob didn't light up and the reading stayed the same. I made a tiny pin hole in the wire to make sure I had contact nothing happend. I searched the interwebbs and seems like if I get that reading with after leaving the battery totally disconnected overnight and not even plugging the MAF back while key on engine off and still getting that reading then it's the ECM since it didn't set it back to zero? Oh snap almost forgot i did take the ECM out and discovered the previous owner had already swapped the original ECM out and put in from I can see a Junk Yard replacement since the exterior shell and the PC board numbers don't match.. Sorry just a little frustrated lol
@@johnny4713ify what are your symptoms and codes? What is the signal voltage reading at the MAF sensor and at the ECM MAF signal pin with the engine running at idle?
@@ScannerDanner bank 1 and 2 running lean. Just checked with engine off key on 12 volts both with or without it connected checked pin hole and again with it off direct. Then just turned it on at idle its reading 14.11 volts same pin hole reading connected then taking it off and connecting it directly to MAF its reading the same 14.11 used Multimeter
+Daniel Warren It does, but it is designed to read a differential psi when the EGR opens. If psi is the same on both tubes, there is no change in signal voltage. So with the EGR closed, I cannot use this sensor to tell me anything relating to psi in the exhaust. Make sense?
+ScannerDanner I think I understand. The sensor is reading the pressure but the data pid doesn't show that, it shows the difference in pressure, Is that right? Dpf pressure sensors are identical but I'm sure the data pid will show you the actual pressure in front of the dpf.
The voltage trace was not good my friend. look at 10:04 on the scan data graph. If you have a good voltmeter, you may be able to catch the glitch in the signal
J Love do yourself a favor. If you can't afford something like a pico scope then look into a hantek 1008c. It's a cheap oscilloscope with automotive based software you can get for less than $80. I have a pico 4425 I keep at the shop but I wanted something cheap to keep at the house in case I was doing something there and it gets the job done.
Youre not showing test and just saying your viewers have been helping you understand grams per second and that you also believe this or that. Ive seen good videos but this one is not good.
, can you recommend a scan tool like Auto tap or enginenuity for 1988 Ford Econoline OBD1 can't seem to find them. Low dollar medium price high dollar choices recommended. Thanks love to all Jeff
, can you recommend a scan tool like Auto tap or enginenuity for 1988 Ford Econoline OBD1 can't seem to find them. Low dollar medium price high dollar choices recommended. Thanks love to all Jeff
Those are all OBD2 (1996-newer) scanners, they're not gonna work on a 1988. Sears has a decent CRAFTSMAN scanner that works with OBD1&2, I think it runs for $270.00. Check it out!
