Bob. I have the Lima 2.5. Idling at 800rpm, coolant temp @182, MAF is 23 cfm. His truck idling MAF reading is 50cfm. Is mine wrong? Is his wrong? Are they both correct because they are different engines?

1999, Reg Cab, 2.5, 5 speed, 145k. (Sent from my DROID BIONIC using FRF App)

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

My thoughts. Please correct me if I am wrong.

Did the OP ever do a fuel pressure test?

It is probably not a leaky injector because both heads are rich?

I think I read that the truck has an after market exhaust. If so, is it possible that it is just restrictive enough to cause the slightly rich condition.?

Could something else be causing a restricted exhaust?

Could a faulty ECT sensor cause the rich condition?

1999, Reg Cab, 2.5, 5 speed, 145k. (Sent from my DROID BIONIC using FRF App)

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As I think this out. The 3.0 is a larger engine so it should have more CFM of air going thru the intake.

FYI: WOT my MAF is @450 cfm. The OP said at WOT his MAF was @ net 250cfm. I am not sure what net? means?

1999, Reg Cab, 2.5, 5 speed, 145k. (Sent from my DROID BIONIC using FRF App)

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

I don't think so. Maybe he can update if he has.

True, probably not. Still possible in the unlikely event that there were leaky injectors in both banks.

The mass air system should have no problem adapting to an aftermarket exhaust in good working order.

Plugged cat or muffler but that should show up as noticeably decreased performance.

Maybe but should be easy enough to check. After an overnight cold soak, ECT and ACT signals should read very close to the same voltage/temperature (before starting the engine).

I don't have any info on mass flow rates, just MAF voltage. My 2003 Ford reference says that the 2003 3.0 MAF signal should read about 0.8~1.1V at hot idle. However, I couldn't say if that range is correct for any other year 3.0L.

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2003 FX4 Level II, Supercharged 5.0L V8, Headers, Duals
BW4406 manual transfer case, Aussie Locker, Torsen L/S, 4.10's
Bilstein 7100 rezzies, Cadillac/Mustang rear discs, Duff traction bars
Keypad Entry, Lock LEDs, ABS switch, sway bar discos
Heated seats, Explorer EATC, Trip Computer and consoles

2003 XLT 2.3L M5OD-R1 reg cab, 2011 Taurus SEL, 2016 C-MAX Energi Plug-in Hybrid

Great info!.......I never thought of checking the coolant temp against the intake temp when cold as a way to check the sensors calibration...brilliant .......my $20 Torque pro scanner is great, however no sensor for Maf voltage is showing up....thanks again

FYI: My 2/1 o2 is showing 1.27 V.
1999, Reg Cab, 2.5, 5 speed, 145k. (Sent from my DROID BIONIC using FRF App)

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

This morning i checked the coolant it was 28f and the intake was 23f. I am guessing the actual temp outside was about 20f..................CEFGW?

1999, Reg Cab, 2.5, 5 speed, 145k. (Sent from my DROID BIONIC using FRF App)

__________________
2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

Good idea on the temperature comparisons. I'll go ahead and do that today.

I did not do a fuel pressure test.


Finished off a tank yesterday and averaged 16.7mpg, which is right on target. Plugs are healthy, and performance is still right where it should be.


Such an odd issue.

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Something I also just noticed - the clutch fan is always running. Could this be caused by a bad relay, or bad sensor?

Any new update?

My CEL light popped on this week and I have code P0172 and P0175. When I reset the codes they reappear in about 10 miles. The truck runs just fine and once my wife comes home I'll check the O2 sensor voltages with my scanner. I need to get this thing inspected next week so I'm working hard this weekend to get her fixed.
2002 3.0L Flex

Took her on a 1800 mile road trip on our move from Houston to NYC and she made it without a hiccup. the fault codes are still there but I firmly believe the truck is being a hypochondriac. everything is running great, averaged 26mpg drafting the moving truck. I believe it's either the computer or the MAF, as the MAF had a higher-than-zero reading (like 27cfm or something) when the truck was not running. I would start there.

That's odd but glad it's running well.

I scanned my sensors and one of the upstream O2 sensors isn't moving like the other. It stays right around .650+/- volts and moves just a little while the other one is up and down like it should. I think that's my problem and since the truck has 105,7xx miles, I just bought all three O2 sensors and will change them tomorrow afternoon.