Optical Sensor Question

[ff43sc]

I read in a previous post that the optical sensor can sometimes cause stalling. Is this something that can be easily removed and cleaned or will it cause a problem to try to remove it. i am going to check my electric connections tonight as my truck has stalled a few times recently and today while driving it missed almost like not getting enough fuel....last winter the fuel tank , fill spout and sender were replaced along with all the fuel lines, fuel pump etc due to severe rusting of tank, spout. resulting in alot of water in tank, tank was dropped replaced and all new fuel...worked fine through summer until about a month ago when these problems developed...

[suburbanK-2500HD]

Hi

do you get the SES lamp, or any other codes. when this in happening.?

[ff43sc]

no ses light, no sts light, no codes on scanner....very intermittent...

[Hubert]

NO ses light indicates PMD/FSD or fuel delivery related. I'd check lift pump, fuel filter, and battery connections. Also consider get a spare FSD/PMD. For your daily driver you depend on Dtech or latest Stanadyne new in box. Buying a used FSD/PMD one only muddies the trouble shooting water in my opinion.

Not sure if you regularly use diesel fuel additive but I would suggest it and making sure you use good fuel.

I believe low lubricity fuel puts more strain on the fuel metering job of the IP/FSD.

[Hubert]

The optical sensor is inside the IP. Not for the faint of heart but doable I have read. It will throw a code if bad more than likely.

[ff43sc]

I cleaned all the connectors on my IP harness today and installed a #9 resistor. when i removed the optical sensor connector, the inside terminals were wet. It is leaking diesel fuel into the connector....none outside, Is this normal? or does that mean the sensor has a seal leaking and could this be the cause of my intermittent stalling?

I see the snap ring on the top does it simply lift out or require special tools/procedures...and how much do they cost...

i had read before about the "filter" harness between main harness and the optical sensor. I had my pump replaced about 4 years ago. but this is the original filter....
I am considering replacing this, as my truck is 13 yrs old, has 230,000 miles and has recently been "missing occasionally...

i will be replacing pmd with remote mount, harness, etc also soon.....
as always thanks for all replies and any help you can provide....

[Hubert]

I cleaned all the connectors on my IP harness today and installed a #9 resistor. when i removed the optical sensor connector, the inside terminals were wet. It is leaking diesel fuel into the connector....none outside, Is this normal? or does that mean the sensor has a seal leaking and could this be the cause of my intermittent stalling?

I see the snap ring on the top does it simply lift out or require special tools/procedures...and how much do they cost...



Thats just part of it the connector and maybe some electronics potted in a housing that goes through a top cover on the IP I think. The optical sensor itself mounts in or on the cam ring a little farther inside the pump. It reads a slotted wheel connected to the rotor of the IP its to measure IP time accurately.

If the PCM does not get a good signal from the optical sensor it will code after 4 or 5 misreads in a row. Now if its fishbiting or rough drivabiltiy it could be an issue with the filter or wet connections. But stalling generally points to bigger things. And I am guessing pretty confidently if it were a miss big enough to be a stall due to optical sensor error it would code. There are something like 255 windows that it reads per revolution of the IP rotor. You might find some pictures if you search for posts talking about optical bump mod.

[ff43sc]

I picked up a filter harness and also installed a DTECH pmd w/remote mount kit yesterday. The truck seems to be running stronger and hasn't stalled since they were replaced. I use the truck to plow snow and we have a large storm coming through tonight so that will be an excellent test...
thanks for the info....