|
|
Post by Mike the marksman on Jun 18, 2021 14:48:55 GMT -5
I'm having a frustrating issue with a 2014 Ford focus that I think I've narrowed down, but I just want to get another opinion in case I'm wrong.
Car lost power on the highway, stalled at the end of an exit ramp. Car would restart but only stay running for a couple seconds before shaking and dying, like it ran out of fuel. At first I suspected a bad fuel pump or clogged fuel filter.
Got it home and started doing some troubleshooting. I borrowed a code scanner from Autozone and it pulled codes P2195 (O2 sensor stuck lean, bank 1, sensor 1) and P2227 (Barometric pressure sensor- range/performance). In my research, one common cause of both these codes (though not the only cause) is a faulty mass airflow sensor. I disconnected the electrical connection to the MAF sensor and the car started and stayed running, but when I re-connected the sensor it immediately starting shuddering and died. I tried cleaning the maf sensor with CRC maf sensor cleaner, but it didn't improve anything.
I'm going to buy a new MAF sensor after work, but before I do, is there anything else that I should look at?
|
|
|
|
Post by Peegoo 🏁 on Jun 18, 2021 15:13:06 GMT -5
MAF sensor is a common problem that causes the symptoms you mention. You're not getting misfire errors, so that rules out ingition coils/wires/plugs/injectors.
How many miles on the engine? I'd do a pressure test on the fuel pump too--just to rule it out as a possible contributing factor.
|
|
JDC
Wholenote
I STILL say: "If it ain't broke, don't fix it"
Posts: 528
|
Post by JDC on Jun 18, 2021 15:19:00 GMT -5
Not a mechanic by any stretch of the imagination but isn't an air filter replacement a good idea either before or at the same time if you're already going to replace the MAP sensor?
|
|
|
|
Post by Mike the marksman on Jun 19, 2021 14:40:37 GMT -5
Replaced the MAF sensor and that fixed the problem. It has about 98K miles and the previous owner put an aftermarket cold air intake on it, which isn't secured very well, and I think it vibrated the MAF sensor to death. As soon as I can I'm gonna get an OEM air cleaner box from the salvage yard and return it to stock.
|
|
|
|
Post by Peegoo 🏁 on Jun 19, 2021 14:48:39 GMT -5
Outstanding! You can often fix a MAF issue by removing it and cleaning it because simply hitting it with aerosol solvent isn't the best way to get it clean. But! If you're taking the time to remove the thing, you already have things disassembled--so you may as well replace it with a new one and be done with it. That is why I didn't recommend pulling it and cleaning it, because that may have not done the trick and you'd have to get a new one anyway.
People often replace the intakes with crap like K&N, etc., to "improve air flow," but that completely subverts the engine designers' intent & specs for the best performance, reduced emissions, and fuel economy.
|
|
|
|
Post by K4 on Jun 19, 2021 18:44:31 GMT -5
I saw this late, it is rather funny that the car will not run with a bad MAF plugged in but will with it unplugged.
One would think the engineers could make it go into limp mode with bad signals and then just light up the CEL.
Good catch.
|
|
|
|
Post by Vibroluxer on Jun 19, 2021 19:53:41 GMT -5
I was in CT when mine started acting up. I was driving to PA. I found that when I was idling, the engine vibrated and chugged then would die but when I put it in gear and hit about 20 mph, it ran pretty well.
I made it home.
|
|
|
|
Post by De ville on Jun 19, 2021 20:11:05 GMT -5
Carburetors had their problems, but...  |
|
|
|
Post by guildx700 on Jun 20, 2021 14:34:54 GMT -5
Carburetors had their problems, but... Yup. The old GM Rochester Quadrajet was a simple but effective carb, used in many cars. When modified properly it was a great carb, and the 800 CFM big bore version of it could support decent horsepower levels. Biggest flaw was the soft aluminum throttle body that the throttle shafts ran through. The steel throttle shafts would wear the shaft bores in that aluminum throttle body and cause issues with the carb. Most folks never found that problem, and after replacing the usual float and such finding the carb still had issues they'd ditch the Quadrajet for an aftermarket replacement. I actually had a kit to repair the worn shaft bores. It consisted of a long, stepped size drill boring bit to rebore to fit bronze bushings in, which you would secure with epoxy. That repair would last almost forever. I made a lot of money performing that on endless numbers of Quadrajets back in the day. |
|
|
|
Post by LTB on Jun 20, 2021 15:13:48 GMT -5
I saw this late, it is rather funny that the car will not run with a bad MAF plugged in but will with it unplugged. One would think the engineers could make it go into limp mode with bad signals and then just light up the CEL. Good catch. Yep they often did this (make it run bad) so you would replace the defective item that helped emissions. |
|
|
|
Post by Mike the marksman on Jun 25, 2021 8:15:48 GMT -5
$60 later, between the junk yard and the Ford parts dept I finally pieced together a factory air intake and threw the cheap CAI in the dumpster. The car is quieter (no more intake noise), looks cleaner under the hood and seems to run much smoother. The salvaged air cleaner box still had a MAF sensor in it, which I cleaned and put in the glove compartment, just in case.
|
|
|
|
Post by Leftee on Jun 25, 2021 8:43:20 GMT -5
It’s not the cars/trucks so much as what people have done to them.
I see that a lot in the class 8 truck world.
|
|
