[ancientmariner]

I have a 2005 Mariner 3.0L 4WD - I bought the car a while ago, for $700, with a cracked windshield.
It has about 150K on it now, and I've worked through various issues to get it drive able.

Among other things, it has a rebuilt PCM (Circuit board medics), new fuel pump, injectors, cops and plugs.
At this point it seems to run mostly great - Lots of power and acceleration.
BUT, I have persistent codes P2196 / P2198, along with an intermittent hesitation from stop, if it's fully warmed up.

I've changed out both upstream O2 sensors and the MAF sensor - Still get the codes .
So, does anyone have an idea where I might look next ?
Sorry if this has probably been discussed somewhere here, before, but I couldn't find any definite answer.
Anyway, thanks for any suggestions .

 

[JohnCT]

I have a 2005 Mariner 3.0L 4WD - I bought the car a while ago, for $700, with a cracked windshield.
It has about 150K on it now, and I've worked through various issues to get it drive able.

Among other things, it has a rebuilt PCM (Circuit board medics), new fuel pump, injectors, cops and plugs.
At this point it seems to run mostly great - Lots of power and acceleration.
BUT, I have persistent codes P2196 / P2198, along with an intermittent hesitation from stop, if it's fully warmed up.

I've changed out both upstream O2 sensors and the MAF sensor - Still get the codes .
So, does anyone have an idea where I might look next ?
Sorry if this has probably been discussed somewhere here, before, but I couldn't find any definite answer.
Anyway, thanks for any suggestions .

With a scanner, check the short and long term fuel trims and a scanner with live data is even better. Persistent rich is odd.

What's the fuel mileage like? My 05 3.0 AWD does about 16 city winter and 17.5 summer around town.

Great name BTW!

John

 

[tomw]

Did a duck duck... got this:

[Solved] Ford Edge - p2196 and p2198 (NOT Oxygen Sensors)

Affiliate Disclosure: As an Amazon Associate, we may earn commissions from qualifying purchases from Amazon.com. Here is a list of tools I use every day at the shop. Let me know if you use them too in the comments!

www.diagnosticmechanic.com

stuck purge valve... and a list of other opportunities for investigation beyond O2 sensors & MAF.
tom

 

[ancientmariner]

OK - Fuel trim :
Keep in mind that I'm a real dinosaur when it comes to interpreting this stuff, but I do have a low end scanner, and I just got back from checking this. Got the car up to temp, and checked parked - Not driving around.
@ Idle - STFT = -28% +/- LTFT = -3.9%
@1500 - STFT= -30% +/- LTFT = 0 %
@2500 - Similar - I didn't write them down
So, yes, with negative numbers like that, I guess I have a problem - Engine is running rich, but I kind of knew that.
The only driveability issue is the sometimes stumble, coming from a stop - Especially when engine is fully warmed. BTW - Pretty crappy gas mileage, I'm getting about 14-16 mpg. on highway.
At speed, it has plenty of power - It will downshift and wind right to out 5K, to pass someone etc, so I don't think it has severely clogged cats, or anything like that. But like I said, I'm a dinosaur, and they weren't very smart, I'm told.

I could check live data driving it, but it just seems out so far with no load, that I don't know if it would tell me anything different. I wish it was a perfect world, where the scanner would just say THIS sensor, or THAT one is toast, etc.
The problem is that I just don't have enough experience to know the most likely suspect.
I guess the next thing to change will be the evap purge valve - I will report back.
Thanks again.

 

[dwightbresemann]

Charts.

 

[ancientmariner]

There's my problem - I don't understand this.
The first chart says that the P2196 rich code is set because it's actually too lean ??
I don't have a P2195 code.
I'm doomed, I think ......

 

[dwightbresemann]

My experience, when I get these codes on a Ford product. I find bad injectors. Replace all injectors with NAPA Echlin. Clear KAM

.

 

[dwightbresemann]

You are reading it wrong. The PCM has lost control of fuel trims. At one moment, the PCM thinks it's running lean, so it adds fuel, but it's now over fueling and the PCM has lost control.

 

[dwightbresemann]

Verify you have 5 volts to the fuel pressure sensor.

 

[ancientmariner]

5.02 V at pin #2. Maybe sensor itself is bad - It's a Bosch unit, was in the car when I got it.
The injectors are almost new - Maybe at most 150 miles on them. Not NAPA - Ultra Power from Rock Auto, I think.
I'd like to eliminate sensor problems before I swap out the injectors, again. But maybe that's wrong thinking.....

 

[dwightbresemann]

The fuel rail pressure sensor connector, is a 3 wire, or 4? Does it have a vacuum line to the sensor also? Do you have a scanner that can show PIDs? Do you have a fuel pressure tester which you can T into the fuel lines?

 

[ancientmariner]

Sensor is 4 pin - Exactly like in your drawing
Yes, has vacuum hose.
Yes, my scanner does PID's - Not that I know how to interpret.
Yes, I have a decent fuel pressure tester, but my 2005 does not have a schrader valve on the rail.

 

[dwightbresemann]

Correct, it won't have a schrader test port. You'll have to find a fuel injection test kit with Ford quick disconnects. With a fuel pressure gauge plumb into the fuel line, you would compare the fuel pressure PID to the pressure gauge (test HC19).

Back to the current injectors installed on the vehicle. Rock Auto have different priced injectors. Naturally, we want to save some money, and we buy the least expensive injectors. Can you read an injector # off one of the injectors and google it? Another test, when shutting the vehicle off (scanner attached), turn the key back on, but don't crank, and read the fuel pressure PID. Does it bleed down, or hold pressure?

Also check the vacuum line to the fuel regulator for any cracks.

I'm posting the correct PIDs valves for your vehicle to compare with the scanner. Page 3 had PID INJ 1-6 open time in MS. If your values are lower, you have bad injectors.

If you were looking for a silver bullet, replace all 6 injectors with good NAPA parts and clear KAM.

If you need more test procedures or diagrams, I'll be happy to help.

 

[dwightbresemann]

Another item to check is crank/cam timing. Since the codes are for one bank, a one link jump can and will cause these codes.

 

[JohnCT]

With regard to 5K rpm - I've had three of the 3.0 V6s, and all made their most power above 5K and they were still building steam when they upshifted (probably to protect the mechanicals). When I had a plugged lower cat in my 05, it would not rev until I emptied it.

How your rich condition affects the rev I don't know, but I hope the rich condition didn't poison the cats.



John

 

[ancientmariner]

Obviously some things I can check, now. I need an adapter for my fuel gauge - More tools to buy :~)
I doubt it's cam timing - The codes are for both banks. If jumped cam timing was the case, then I need to re-think my strategy for the whole car.
I'll see about the injector #'s - I'm not dead set against changing them again if it fixes the issue, but I want to check everything else first.
I just checked the price on the Echlin injectors - Wow! - I'm sure they're fine injectors but ......
Even new Motorcrafts are cheaper - If they were the problem, would the Motorcrafts not work ?

I don't usually have that heavy of a foot, and haven't pushed the rpms, just to see what it could do - It's already an expensive little car ;~)
As far as poisoned or plugged cats go, that's also one nightmare that might just put the end to this whole exercise.

 

[tomw]

maybe not relevant, but with trims way negative, the ECM is trying to cut back fuel by decreasing the injection 'open' time. That can be a case where one injector sticks open and provides too much fuel. The STFT and LTFT being negative on one bank would give a hint, both banks, I would be considering a too-high pressure condition as a possible cause.
If you can access the fuel pressure, two things to consider. First to be the prime run for 3-5 seconds @ key ON. Watch pressure build, and it should maintain pressure w/o dropping like a rock. Same with turning the key OFF, pressure should maintain for some time unless there are leaks. Older models had diaphragms that could leak, or leaky return valves or leaky check valves. Newer don't have a return, so a bunch of failure points are eliminated.
tom

 

[ancientmariner]

I want to thank both you guys - You've given me a lot to think through, and it's a good prompt to change the way I think about vehicle repair. I'm actually pretty good with straight mechanical stuff, and have rebuilt a couple engines that turned out well.
Getting my head around the diagnostics on electronically controlled cars is hard for me - But I'm trying to climb the curve, just finding it a bit steep, is all.
I have to go away for the weekend, but I'll be back on it after - I want to see this through, and will report progress.

 

[dwightbresemann]

I stand corrected, you are correct, these codes are for both banks.

Reading code description for P1296. First, the PCM detects a lean condition, and tries to correct this lean condition by lengthening injector open time in mil seconds to enrich the air/fuel ratio.

It was during this enrichment, the PCM lost control.

First, why did the PCM think it was running lean. Second, why does it think it running overly rich when trying to correct for the lean condition.

We know the front oxygen sensor report air/fuel ratios to the PCM. I wonder what would happen if you disconnect both front Ox sensors? I don't know if it can happen with your vehicle, but make sure the Ox sensors connectors have not been switched between banks. Seen it before.