Left last Friday early in the AM heading to SEMO to try and shoot some snow geese.  There were others going, so we caravanned in two vehicles…………..one was mine.

 

About 1/3 of the way down, it starts snowing.  Fifteen minutes later, it's really snowing.  Another fifteen minutes later, and the interstate is essentially one lane.  The snow started North of Bloomington, IL and finally petered out about halfway between Springfield, IL and St. Louis, MO.  Between Bloomington and Springfield was a nightmare. Must have seen 30 cars drive off the road!!!

 

But that's not the "ordeal"!!!

 

Just North of Springfield, my truck starts getting a real touchy throttle. I'm running 45-50mph in the snow, and I touch the throttle and it was like I really mashed it. Pulled over into a rest area to let the dogs out.  Left my truck running…………idles normal with normal rail pressure.  Going out of the rest area, the throttle ramps up slow, and then fuels hard at about my normal shift points. Not enough for my two passengers to notice, but for me to notice.

 

Further down the road, the snow lets up, so we can drive a bit faster.  However, the rail pressure isn't going to where it should and the truck starts a "detonation" sound.  Normally at 65mph rail pressure is 16-17,000psi on my truck.  During this stretch it wouldn't go above 13,500psi.  After a while of milking it up to speed the rail pressure came up, but if I gave some throttle, all I got was the detonation sound.

 

Get into MO and stop to eat lunch and chill after driving thru the snow storm. Should've been there in about 4.5 hours, but it took 7.  After lunch, go to start the truck, and it sounds like my '99.  Rail pressure is low and CEL is on.  Shut truck off and pull out my Smarty to check the code……………P0192………….Fuel Pressure Sensor Reading Low.  Clear the code, and start her again, and she's back to normal idle.  Pulling out of the lot to get back on the Interstate………………she's slow to ramp up and then seems to fuel all at once but level off quickly.  In MO, she's running  65mph but if I try to go faster the detonation sound starts.

 

We pull over to let the dogs out again, and I open the hood for a look.  I decided to open the air filter housing……………….full of snow, and the pleats of the filter were ice coated.  OK, that's my problem I think to myself.  Clean the box out and as much of the snow, ice etc. off the filter.  It's in the teen's temperature wise also. I forgot to tell that earlier.  Button her back up for the last 80 miles of the trip;  but it's the same as before.  Get to Sikeston, MO;  check into hotel, unload and I fart around with the truck, trying to figure out what's up.  Get some dinner………………….to and back for the restaurant it's still the same.

 

Next morning, start her up to head to the hunting spot……………starts up fine.  Get on the road, and once she warms up the throttle thing starts again.  Hunt all day……….lousy day hunting…………….late afternoon start her up to head back to the motel.  Starts normally and actually drives good.  Thought that it just might be moisture somewhere and the 40* temps got it out.  My truck hadn't seen 40* for probably 2 months prior to that.  But once up to normal operating temp, it starts again.

 

Sunday morning go to start her up.  Normally when I turn the key to let the grid heater cycle, the lift pump comes on (Walbro approx. 25psi) and my Quad rail pressure gauge will read 2-3x10 which makes sense.  However, it read a big fat 0.  Started her up and it sounded just like after the restaurant stop, only worse!!!  No way I was gonna move it as we were going hunting, so we stuffed everything into the guides truck.  The hunting was no better than the day before, so we called it early.

 

Get back to the motel.  Truck starts fine, but there's no way I'm gonna attempt to drive home with it acting like it is. I'm not gonna have it puke out on me in the middle of BuFu nowhere!!!!!  So we load all non-essential gear in my truck that they don't need and add one person and 2 dogs to my Buds truck!!!

 

 

 

 

You think something might have froze up? Or just the lift pump is going out? We took a long trip this weekend too but we were lucky enough to not have any problems whatsoever with the truck. I will tell you what, 1200 miles in one day, twice in one long weekend is to much.

My first thought was a sensor out of whack, but that won't throw a rail pressure code since it doesn't think there is anything wrong.

 

My rail pressure reads 20 with 0 pressure, just the big range of the gauge.. so I agree with normal.

 

Was fuel pressure normal while the driving issues were occurring?

 

A failing FCA shouldn't effect throttle sensitivity, unless it's pushing a lot more fuel than needed (i.e. more power) that will also cause the detonation sound. Did the rail pressure ever seem high? I haven't personally seen low rail pressure cause the sound, but I suppose it's possible. I cruise at 12-15K psi with my current tune and no noise.

 

When are you headed back up?

 

EDIT: It could very possibly be a faulty rail pressure sensor. The pressure might not be reading correctly (explains the P0192) and would open the FCA to get the pressure up. If the pressure was really higher than the reading claimed it would explain the throttle sensitivity, and timing rattle.

 

You are correct not to drive it, if what I just stated is true you could be running 26K psi and not knowing it.

Get the room for another night.  Get my essentials in the room and grab the phone book.  There is a Dodge dealer in Sikeston, as well as fuel injection place, and a Cummins place!!!!  Call the Cummins place, as they have 24 hour assistance and talk with a fellow.  Tells me that they don't have the diagnostic equipment for my truck.  I tell him that I know that, and I tell him I have the code reader (Smarty) and what it is.  He tells me basically what I already know that it could be the sensor or something causing the sensor to throw the code.  Thank him, and hit the lobby computer in the hotel.  I couldn't remember my password or I would've logged in to get some of y'alls phone numbers in the emergency section.

 

So I wind up spending a hour or so here and scanning other sites about the P0192 code and causes and symptoms.  I decide that it's either the "rail pressure" sensor itself or it's the FCA (fuel control actuator).

 

Monday morning, the truck starts normally and I drive the to fuel injection shop;  as it said in their Yellow pages add that they do Bosch systems.  Get there, and we talk, and it's decided that the Cummins place is a better bet as they deal with the "older" systems and not the new.  They had no experience with my year truck either.  They could've ordered me parts……………….so I went to the Cummins place.

 

Get to Cummins and talk with one of the mechanics there about the symptoms and code.  He doesn't know exactly what I saying, but he knows enough to verify my thinking.  He agrees that it's probably either the sensor or the FCA. He was leaning toward the sensor. He said I could borrow whatever tools I needed from him also to swap parts.  Go to the parts guy…………….no sensors in stock, all are down in Memphis but they can get it the following morning.  They have a FCA there in stock.  So I tell him to order the sensor.  

 

Next morning go to start the truck.  0 rail pressure again on my gauge and code P0192 again.  Truck sounds worse than ever.  Turn the truck around so I can get some sun under the hood to see and shut her down.  This is the best "light" I've had to fart around under the hood since this all started.  Anyhow, I pull the sensor plugs apart and I can see some green corrosion in the plug on one terminal. Try to clean it up (45 minutes and several tries), but the truck still running like crap. Throwing code each time.  Finally I go back to the room, grab the  phone book, in case I needed a tow, and decide to try to nurse it to the Cummins place.

 

Long story short, buy the sensor, borrow the tools, swap the sensor, and truck was back to normal.  Returned the tools and showed the mechanic the sensor……………..said he's seen worse that still worked fine and better that were junk!!!  Anyhow cleared the code, drove around the Cummins neighborhood until the truck got to normal temp and put on 10 miles close by.  Twas fine, so I headed home and truck ran great. Right around 500 miles and I'm between 1/4-3/8 tank left.  So, yeah, she ran good coming home without any of the symptoms prior.

 

Rail pressure sensor part Cummins part number………..3949988.  Cost me $215.00 and 2 extra nights in the motel!!!!

Glad you have it home now, I bet it was a stressful wait.

Do whatever you think is best John.

 

Glad you have it home now, I bet it was a stressful wait.

 

 

It was actually "hard" for me to enjoy the hunting because of my truck.  I was running thru scenarios (good and bad) in my mind while laying out in the rice field.  You know……………if this, then that, then that, then that…………trying to think what was up with my truck.  The worst day was Monday after I got back from the Cummins place……………….it's 10:30AM, I'm in a hotel room, the guide is out with another group of hunters and I get to watch TV all day!!!  Stircrazy to the max!!!

 

Taking MightyWhitey to the Dodge dealership it Sikeston was a total last resort.

 

The post which contains all the 3rd gen codes was a huge help to me. I could go thru the diagnostics (minus the DBR III) with my Smarty to a point.  And after talking to the mechanic at Cummins, we both agreed to try the sensor first.

 

Shazam………………it worked to!!!

Haha, yeah I know the feeling. When my truck broke it was on the way into Elk camp, added some stress the first few days for sure!

Glad you got her fixed, nothing worse then breaking down on your way to the hunt, or vacation, or wherever your going. Puts a real damper on what's supposed to be a good time.

I remember a discussion a while back about what extra parts to take on the road, and my reply was no parts to speak of but I do carry the essential sensors. There was some discussion for and against, but this is the exact reason I carry the.essentials. They don't take any room up to speak of, they can fit right in the glove box if need be. As our trucks age, there is no telling how long they will last or when they go.. I can service my rig top to bottom on the mechanical side but them electrical gremlins can come up out of nowhere. It's just one of those things that makes me uneasy leaving far from home, which I do a handful of times a year, and carrying my Smarty and the basic sensors helps to ease that concern a little.

I am slowly building a road trip box that currently has a vacuum pump, water pump, and belt. I am going to start collecting sensors.

 

The box will only get put in the truck when I am going a ways from home.

The water pump is not a bad idea, I do carry an extra belt as well. I also have my OEM Carter lift pump mounted on the block in the event of a lift pump failure. All I need to do is switch 2 ball valves around and plug it in, good to go. Not so important for you CR guys but a real deal breaker for a VP truck when a lift pump goes.

I forgot to mention a couple things in my above thesis………………...I put my truck back to "stock" tune on Sunday afternoon farting around with it. I did this just in case I had to take it to the Dodge stealer in town.  I did not clear the P0192 code when I did this.

 

Once the new sensor was in, and the truck was running normally, I didn't reconnect my Quad rail pressure gauge.  I didn't want to take the chance of unplugging the sensor and FUBARing something up when I'm 500 miles from home!!!!  Funny thing…………my rail pressure gauge read 3750psi + or - 5psi being unplugged with the power still connected!!!

 

Driving home I didn't notice much difference being stock while cruising……………the big difference is rowing thru the gears……………….torque management/fueling is greatly reduced.  I hadn't driven it stock for a long, long time.  I reconnected the Quad rail pressure gauge today also.  Cleaned up the terminals/plugs and all is well.  I put some high temp. silicone on the top of the plugs because there is a void/depression there that can hold water/moisture.  I think I mentioned above that one terminal had a bit of green copper corrosion on it.

Just under 900 miles driving on "stock" tune since my "rail pressure sensor" ordeal almost 2 weeks ago.  It's truly unbelievable how the Smarty "wakes" our trucks up on the "low end" vs. the "stock tune" from the factory.

Haha, I hate driving on a stock tune. I haven't tried a stock tune on the current build thou, it seems to would be a lot peppier with the BBi's but still doggy and laggy compared to a Smarty tune, and UDC is almost as different again.

 

How far has your mileage dropped off?

Haha, I hate driving on a stock tune. I haven't tried a stock tune on the current build thou, it seems to would be a lot peppier with the BBi's but still doggy and laggy compared to a Smarty tune, and UDC is almost as different again.

 

How far has your mileage dropped off?

Mileage has not dropped off at all.  That's what surprised me coming home after the sensor fix…………I got great mileage…………..20.7mpg running 65-68mph.  I didn't notice the stock tune cruising the interstate at all……………just rowing thru the gears.  Takes way more pedal for some oomff!!

 

I'm heading back to MO this weekend to snow goose hunt again.  I'm gonna drive down on the stock tune, but prior to the way back home, I'll re-install SW-5 for a quick comparison.

What rpms do you cruise at?

 

I really noticed the stock tune towing about 8K lbs last summer, even the slightest grade in 6th at 65 would send the truck into WOT.

68mph on my truck = 2000rpm.

68mph on my truck = 2000rpm.

 

That's why, if you were to bump above 2,000 rpms the timing starts to fall off VERY fast and so would mileage. But at low load and 2,000 rpms and below the timing is decent. In fact based on how the OEM cruise timing table looks the free spin kit potentially adds more mileage on stock than tuned.

 

Are you on stock sized tires? I looked thru some old threads but couldn't find it. If they are I would try 67 mph, with 265/70/17's it should be 2001 rpms with new tires (increase as they wear). The closer you are to 2000 rpms the better the timing, in fact dropping to 1990 rpms would net better mileage yet.

Stock sized tires with about 49,000 miles on them.

 

Cruising 65-68mph my boost usually is 4-5psi. Bumping up to 70-75mph the boost needed goes up to 7-9psi all things being equal.  Similar findings according to my RP gauge also.  Just bumping up the speed that little bit really drops mileage on my truck………….unless I have a good tail wind!!

The stock timing (and maybe Smarty too) really kills mileage above 2000, it's one of the things I fixed on my UDC tune so now I battle wind resistance not timing.

I hope the Smarty guys will get their updates available for Mac computers soon.  One thing about the stock tune is that it's very, very smooth.  Even with me used to the SW5 tune, it's still not as smooth as the stock tune…………………it's not all the torque management either…………..it's hard to describe.

 

IIRC, you said the latest software is much smoother than prior versions.

Edited February 25, 201411 yr by dorkweed