Det 1

I'm in the long process of attempting to diagnose a stuttering problem with my truck. It appears both sensors are the same part number; do they operate independently, simutaneously, or in cooperation with each other?

CoastalDav

See the thread next to yours. Similar problem. The info we provided was not the problem there. It could be yours.

https://www.dieseltruckresource.com/...r-t259265.html

Dave

Det 1

Been there, done that. Saw the sticky that used to be up above and one of the first things I did when this problem raised its ugly head was check the wires, tape them individually, and put a plastic loom over the entire harness. This saga has also led me to replace the TPS, fan clutch, govenor pressure sensor, and extra ground straps from the motor to the frame. Each of which has resolved it's particular issue, but hasn't fixed the stutter. I've driven the truck with the tech in the passenger seat watching the star scanner/monitor. When the stutter occurs there's not been anything noticable indicated on the scanner, but lead the teck to say "Boy, that was severe". It's been a very frustrating 2+ years and has led to the original post. If it's not either of the sensors, or both, then the most likely next stops are ECM or transmission (any one want to take a guess which is the most probable?). Both sensors are to be replaced this Friday. Not being much of a gearhead, I'm just curious how they function. Thanks for the reply, though.

CoastalDav

Please post the result if you find out want is causing the shutter. I suppose you've been thru the injector wiring harness as well.

Good luck.

Dave

Det 1

Frankly, no I haven't checked that. This isn't just a simple miss; i.e. one cylinder failing to fire. I believe it's either a total, temporary interruption of fuel flow or a torque converter lock-up issue. If it's fuel flow about the only things left to look at are the cam/crank sensors or the ECM. If it's the transmission it's either an internal transmission problem or the ECM. A local shop, a dealership (reliable), and a phone conversation with Dave Goerend (nice guy) have been involved and have different opinions on the cause. No one has been able to definitively diagnose this issue so I'm using a least expensive-most likely approach. The sensors are the least expensive and (my opinion) the ECM is the least likely. If the sensors don't cure it a Goerend tranny is likely in my future. The truck has 140K on the clock and I tow a heavy 5er. I'll make a post when we find a cure.

dieselfreak21

Have you had the injector checked? 140k is about the time they go south and based on you signature I assume still running the factory filtration. They need a leak down test done. Also if the harness is bad it could be cause. My truck would do the same thing. Had injector rebuilt and hasn't happened yet in about 5k miles.

browndg

hope this helps,I had bthe same problem for about 6 months, changed the cam sensors and the problem stoped for a while. short version, there was a wire coming from my remote start connected to or sharing a tach wire that was interffering with the signal of the cam sensor. just thought i would share my results, no more hic-ups.

Det 1

Thanks for the suggestion. I'll see if they can do that while it's in the shop on Friday.

cLAYH

I have a similar problem, when it happens it throws a crank sensor code but I replaced both sensors and checked all the wiring as per the sticky thread. Only seem to happen in high RPMs.

Mine's a stick so its not a TC/tranny problem.

Thinking of pulling off my CPS tone ring and seeing if its damaged. It has had its mounting bolts reamed out to be turned back some to increase timing but I put it back to the stock location when the edge went one.

I've even tried a completely different set of injectors for awhile and it didn't help.

Det 1

Well, if we make the assumption (and that's dangerous) that we all have common problems then maybe we can narrow it down. 1)cLAYH has replaced his sensors but the problem persists. I haven't gotten any sensor codes but I'm replacing them just to eliminate the possibilty they're the cause. So, for this exercise we'll elimnate the sensors as the problem. 2) Both types of transmissions are involved so we can take them out of the equation as well. 3) cLAYH replaced injectors with no positive results. 4) I've put tape and loom on the wires near the A/C high pressure line but that made no difference.
With the information posted so far the remaining possibilities are the injector suggested by dieselfreak21 and the remote start/tach wire issue suggested by browndg. I do have a remote start on my truck.
Browndg, can you advise how you changed the connection to resolve your problem?

cLAYH

No remote start on mine. However we do have a few differences. I get a crank sensor code and you get a cam sensor code.

Also just because my sensors weren't the problem doesn't mean you don't have one. You could try swapping the sensors and seeing if that changes the codes.

On mine jiggling the wire harness near the crank sensor sometimes makes the problem go away for awhile other times not. Its really tough to diagnose as it comes and goes. Might do it all the way to work one day but be fine coming home and not do it again for a month or two....

Det 1

My truck really had the stutters today. I was able to get a good transmission tech to take a test ride today while it was acting up. He was "pretty sure" it's not a transmission problem. Most helpful was that he was able to get me hooked up with a shop about 20 miles away that does a lot of work on pulling trucks. This is his slow season so I, after another test ride, I left it with him for a few days. He's going to swap out the sensors to see if it has any effect. He's also going to check a couple of grounds between the ECM and the motor that, according to him, can affect the tranny at shift points. One thing that was a constant today, whether in OD or in tow haul, was that the shudder always happened while under light acceleration. Neither tech would rule out a transmission problem, but both were leaning away from it. Hopefully I'll find out by the end of the week. Whenever, I'll be sure to post the resolution, or lack of it, here.

Det 1

Well, crap, we thought for awhile we'd cured the problem. Swapping out the sensors didn't make any changes, but the tech thought he'd noticed a consistency around 1400 rpm. We're pretty sure the previous owner had a programmer on the truck. The tech thought maybe when they'd removed it not all of the programming got put back to stock, so he temporarily installed a Smarty Jr. He ran it for several miles and couldn't get it to reproduce the stutter. I picked it up and brought it home. It's about a 30 mile trip and the truck ran great until the last 2 miles. Then it stuttered about a half dozen times before getting to the driveway. Have to wait until Monday to see what the next step will be.

AirGrabber

1-Have you checked ALL the connections made for the remote start and the pacbrake? Including all splices and grounds and the controller. Always cancel out any additions to your truck as being the problem.

2- when returning to idle, while in gear, like when approaching a redlight, does your truck still have the studder or rpm's seem to fluctuate more than normal?

Det 1

1)-The stutter problem existed over 2 years before the exhaust brake was installed. Still need to check the remote start connections, but that will take a couple of weeks; the shop that installed it is booked up for that long (I know because I schedule the appointments for them).

2)-No. It will sometimes have a hard shift into first gear, but it's nothing like what is experienced at other times.