2008 Ford Ranger 3.0, Auto 2WD with under 70k miles (verified miles thru yearly inspection & maintenance records.)
The issue is a loss of power and gas mileage. Mostly on highways. There are no codes, hidden codes or any indication that any code has ever been tripped. That’s from my honest mechanic & his fancy scan tool (to use Scotty’s words, lol.) I don’t have the money to throw at it right now, plus the mechanic I go to is usually very busy. I’m not bugging him with this pesky problem.
It’s difficult to explain but I’ll try. Let’s say I’m going 60-70 down the highway with no problems. It will accelerate fine one moment and the next time it won’t get out of its own way.
No loose vacuum hose, and no codes or deleted codes.
Otherwise it runs excellent. Even with a 3/4 load I can move along fine. Only sometimes (randomly) on highway it won’t get up to speed safely. Power feels like it cuts 30-40% and it can’t get out of its own way. Mileage goes way down. Then seemingly randomly it stops and run full power again.
I’m thinking some electrical connection needs cleaning with MAF cleaner. Or possibly a sensor is going bad in this 14 year old truck. It could also be injectors, but I thought that would cause at least 1 misfire at some point and would’ve tripped a code.
Fuel filter has been changed. I keep my air filter fresh and change it often. Oil every 3k. I try to keep maintenance on schedule. Rear end fluid seems clean tho I’m going to change it with 75k coming up, same for transmission. It looks clean too.
Ill be changing the rear end fluid and checking the connections whenever it stops raining this week. Hopefully that fixes it. If not I’ll move onto sensors and cleaning the injectors.
Until then I was hoping someone that had a similar issue could help. I won’t know if it’s fixed until it’s driven for 50 miles or so on the highway. Want to get it fixed quickly because I don’t trust these mid-2000s Ford ECUs.
Intermittent issues like that can be perplexing but you can work them to your advantage.
This sounds like a fuel starvation issue but what's causing it?
MAF, MAP, fuel pressure regulator, IAC or ECT sensor issue, fuel pump,...
or maybe none of the above. Maybe it's something else.
It seems like you have a pretty good grasp as to when this "issue" occurs (when it does).
So how can you work this to your advantage?
Spend around $100 bucks and buy a scanner like a BlueDriver or another one which can Log/Record Live Data.
Record some Live Data when the "issue" is known to happen but doesn't.
Then, when the issue happens record it.
It would be useful to compare sensor values and fuel trims between identical RPMs, Speeds, and Loads when the truck is running good against when it's bogging down.
Did the MAF or MAP sensors "drop out" (maybe wiring/faulty sensor). Did the IAC or ECT sensors "dropout"? (maybe wiring/faulty sensor again)
Are the fuel trims spiking to positive? (maybe a fuel pressure issue)
These scanners are "consumer friendly" and there's plenty of videos on how to use them.
Right now you're "flying blind". You need more information
Thanks. Looked at the MAF Rate. It stays around 1.0 going steady under 2000rpm. Get it over 2000RPMs and it will jump to 5.0 while under load. The worst was for about 3 seconds @ 3700rpms it went as high as 10-11 momentarily when it saw the most stress getting to speed. The more load the higher the MAF rate goes.
I have the new sensor, OEM FoMoCo & they are inexpensive enough. Obviously my next step is to check Live Data after I install. Genuinely looked all over YouTube, plus Car & Ranger specific repair forums, can't find how to get these 2008 3.0 MAF's out.
I'm really pulling on this thing & it's not budging. Pull the tab on the bottom, push in the sides and pull the MAF out. But it will not budge.
The videos & repair guides only showed the photo for prior to 05, which is slightly different than this one. I'm definitely missing a step in this process, and don't want to rip the connector because of that.
PS- Cleaned MAF sensor with about 15 sprays on a warm day & let it sit for an hour to dry while I took care of other things, and it does seem better but I could tell it needed replacing so I went and got one. Here we are.)
General rule of thumb for MAF is 1g/s per liter of engine displacement at idle.
You have a 3.0L engine.
So your MAF should be reading about 3g/s at idle.
1g/s is much too low at idle.
Examine the connection tabs on the new MAF to get an idea of what's holding the electric connector onto your old MAF
Thank you. Which sensors should I record? There's more options than I thought there'd be. I'm taking truck on the highway in the next couple of days. I can record updated live data then.
MAF (Mass Air Flow Rate) is showing lbs\min in the data. Will check if I can display data in metric p/s. At 700rpm idle, warm motor, it's showing 1.0lbs/min - 1.2lbs/min. That's around 2.5-2.98 g/s if my math is right. (I'm no mathematician tho, it could be very wrong, lol.)
After cleaning the MAF sensor, it's gotten much better mileage and power hasn't been an issue. Tho I haven't driven it enough since to be sure.
Hopefully, a new MAF sensor fixes it. Motorcraft part was over $175, no way I'm paying that. Hopefully the $25 Duralast or Hitachi works okay.
You can switch it to metric.
I let the internet do my math.
lbs/min to g/s converter:
https://www.translatorscafe.com/unit-converter/en-US/flow-mass/29-2/pound/minute-gram/second/
(that looks way too high)
Record RPMs, Load, MAF, MAP, fuel pressure (if available), IAT ECT, STFTs and LTFTs
I got the Hitachi MAF sensor in there. Only a single gasket seal unlike the 2 gaskets in the original MC part 🙁 . T15 screws holding the MAF sensor on are begging to be stripped without a quality bit. Alas, it's in there though.
Replaced the part & it ran great for a few minutes. Real smooth and felt good with power. However throughout it's much smoother regardless of power drop and it seems steadier, but power just goes kaput. I'll give it time for the ECU to do it's thing.
Checked it after and no other issues that I saw. No codes. The Air Flow g/s was now running at around 4 g/s which is about 33% too much, but overall running much better than previously. We'll see if my gas mileage goes up, it was losing a few mpgs with the power loss. If not, I'll check the injectors.
Start with the basics - clean your MAF sensor and throttle body and MAP sensor.
Throttle body was cleaned, ports too. I’ll try the sensors next (hopefully it stops raining around here soon). Thanks!
Got a Bluedriver as a gift. Someone must have seen my watch history on YouTube 🤣 (I highly recommend it so far)
Well, popped it in the 08 Ranger 3.0 Auto & got some data if anyone would like to take a crack at analyzing it?
Is there any specific data you'll need? I can do another Live Data recording this week.
I've had issues with power loss, mostly on highways. Check a previous thread from this account to see more details on that. (MAF Sensor cleaning helped a lot but haven't put the mileage on it yet to find out if it's fixed)
Ambient temperature was around 80ºF, nice Sunny day. Driving from a standstill, mostly warm engine & transmission, round a small road very slowly, back around some 40mph backroads and roughly 5mins of 55mph driving as steady as possible.
I've cleaned the MAF with MSC recently but it will need to be replaced sooner than later. It would be replaced already if I could find out how these things come off. Normally it's pull the tab on the bottom and push in the sides but it's not budging. It doesn't appear to be the same coupling after 08 with these motors. So haven't been able to find the answer online or in the standard repair books. (Let me know if this last paragraph should be a separate thread.)
Thanks! 👍
Side note: I have data but it's only about 15minutes worth. This thing is easy to use, I'll plug it in next time i take it for a drive to get a better dataset.
I'd just take it to my mechanic but this poor guy is so busy, i'm not gonna bother him with this.
Sounds like fuel starvation as Jack said. I would measure the fuel pressure.
Jack described in his answer what you should look for in your scan data.
I know the fuel filter was changed but I still suspect it. Was it OEM? Was it installed in the correct direction? You could have had a bad tank of gas and it may wreck a few fuel filters before it clears out. One way to tell is to blow some air thru it. Air should pass thru a working filter easily. I have seen them so clogged you could barely blow any air through them. And I have seen new ones clog up as well.
