Help please! 2005 XLS Fuel Problems (?)

[Bipeman]

2005 XLS 205K mi. Heading down the road the other day I experienced what felt just like running out of gas. Truck shuddered and stalled at a light, re-started and went a block or two, rinse-repeat X-3 times and then basically quit, except... cranking resulted in the engine firing up for a second or two then chugging for a few seconds and quitting.. repeatedly.

Had it towed home and decided it was time to change the fuel pump. Figured it should be done in any case at this mileage. Installed a new Delphi pump. Did not change the (original) fuel filter at this time (I know.. I know). Eureka.. the car fired up and ran fine.. for about 30 miles. Next morning.. the problem began to manifest again... made it home.. about 10 miles.. with the truck nearly stalling at traffic lights, and finding that keeping it revved up seemed to prevent this for the most part.

OK... should have changed the fuel filter .. duhh.. Did that. Found the filter to be pretty clogged up and had some black crap come out of it on the engine side as well.. Was pretty sure this had to be the problem... Nope! Same trouble. Truck will start, run 2-3 seconds.. then start to misfire.. chuggetty chug on for several more seconds and quit. From time to time it will suddenly start to run fine, for one minute plus, in park, when rpm is held up to 2500 or so with foot on the pedal.. then it starts running a little rough, then RPM drops.. more chug-etty chug, and die.

The only code I am getting is 2197 -- O2 sensor.

Spraying starting fluid into one of the vacuum ports (the one net to the power brake vac line) gets her running and seems to keep her running (smoothly for the most part) although I did not want to do that for very long.

Questions come to mind... Did the new pump fail? Did the clogged filter cause that and possibly the failure of the original?

I think the next step is a fuel pressure test. Also a problem with the fuel pump relay comes to mind but seems a bit of a stretch as this would likely be all or nothing.

Sure would appreciate any help.. thanks in advance!

 

[Rick]

Maybe crap made it past the fuel filter and into the injectors?

 

[Bipeman]

Hi Rick, Thanks for the reply... Thought about that but since the engine will suddenly start to "catch" when stumbling around, then rev up and run smoothly for a minute I think it is unlikely that all injectors would clear at the same time to allow that.

Starting to think about the Fuel Pump Driver Unit.

 

[TechGuru]

Need to monitor fuel pressure while it's happening. There is a connector for a gauge down by the brake booster.

 

[Bipeman]

Thanks for that Guru... Figured that was the next step.. and could not find where to hook up. Thought I might have to pull one of the little end caps off the rail. Going to go look for that connector now. Cannot get a test set until later this afternoon.

If pressure is fluctuating / dropping would you say it is the FP Driver unit?

 

[abcducati]

Not sure if you've resolved the issue yet, but the fuel rail sensor is often a culprit in these situations (I just replaced mine this past October). It's located under the air intake on the driver's side fuel rail, and causes all of the same symptoms you described. There are how-to videos on YouTube on how to do it, but be warned you'll need to be patient, as the proceedure is a PITA (there is a video that shows a guy doing it without removing the air intake, but trust me, it's WAAAAY more easier with the intake out of the way). I haven't had any problems since making the repair. Good luck regardless!

 

[Bipeman]

Thanks for the input ducati. I did that fuel rail pressure sensor probably five years ago. Truck liked to take me into an intersection and take a dump. Job was a definite PITA! That rear intake manifold bolt.. arrrgh!
At this point the truck may be fixed or near fixed. Hard to believe but cleaning the mass airflow sensor and replacing the air filter (it was in horrible shape - depended on my oil change place for that) seems to have corrected the problem. I am still getting a P0401 and have a new EGR valve going in tomorrow. Also replaced plugs and wires. First time since the car was new. Interestingly the truck starts a little differently now... used to go "Crank-crank- vroom!!" Now it has a softer start.. that is I can feel a couple cylinders fire before it's completely running. Wondering if it has to do with a closer plug gap. I did not re-gap the new ones and they all looked to be about .035.

 

[abcducati]

Thanks for the input ducati. I did that fuel rail pressure sensor probably five years ago. Truck liked to take me into an intersection and take a dump. Job was a definite PITA! That rear intake manifold bolt.. arrrgh!
At this point the truck may be fixed or near fixed. Hard to believe but cleaning the mass airflow sensor and replacing the air filter (it was in horrible shape - depended on my oil change place for that) seems to have corrected the problem. I am still getting a P0401 and have a new EGR valve going in tomorrow. Also replaced plugs and wires. First time since the car was new. Interestingly the truck starts a little differently now... used to go "Crank-crank- vroom!!" Now it has a softer start.. that is I can feel a couple cylinders fire before it's completely running. Wondering if it has to do with a closer plug gap. I did not re-gap the new ones and they all looked to be about .035.

Keep us informed on how it works after the EGR replacement. Have to admit that vehicles now days are way to integrated when it comes to all the 'extra' parts needed to make the engine run (lol). Best of luck!

 

[Bipeman]

The Final report on this is interesting... Replaced the EGR valve and the P0401 and Bank 1 and 2 Lean codes I had been getting went away but were replaced with P0172 andPp0175 - Rich condition, banks 1 and 2, and the truck was running pretty crappy.. rough idle and surging a bit, and the "soft starting" I described earlier was still there. Very perplexing as I am thinking a rich condition can only be caused by a leaking injector or perhaps high fuel pressure. Posted another thread about this and a fellow said to do a full reset (battery disconnect). This solved all the problems and the truck is now running very nicely, and getting 2-3 MPG better than it had in a long time. It seems that the computer stores some parameters that are not reset when you do a code reset and it was still trying to compensate for the earlier lean condition. Best to all!

 

[abcducati]

The Final report on this is interesting... Replaced the EGR valve and the P0401 and Bank 1 and 2 Lean codes I had been getting went away but were replaced with P0172 andPp0175 - Rich condition, banks 1 and 2, and the truck was running pretty crappy.. rough idle and surging a bit, and the "soft starting" I described earlier was still there. Very perplexing as I am thinking a rich condition can only be caused by a leaking injector or perhaps high fuel pressure. Posted another thread about this and a fellow said to do a full reset (battery disconnect). This solved all the problems and the truck is now running very nicely, and getting 2-3 MPG better than it had in a long time. It seems that the computer stores some parameters that are not reset when you do a code reset and it was still trying to compensate for the earlier lean condition. Best to all!

Glad to hear its fixed. Didn't know until you posted about the ECMs storing older codes, but did know about the battery disconnect trick (actually, a mechanic friend showed me how to make sure the codes are clear by not only disconnecting the cables, but also touching the cable ends together for 10-15 seconds to reset it).
I know the Explrers are a tempermental truck, but they are great none the less. Keep on truckin!