Need help, DTC 17 and 18

[JJ Diesel]

I am new to this forum, and have been trying to find what is wrong with my 1995 K2500 6.5 TD. Constant throwing codes 17 and 18. Always DTC 18 and 1/2 the time 17 and 18. I have done the following in the last 6 months.

new tank sending unit, removed sock
new inline filter
All new lines from tank to engine
new lift pump
new filter and o-rings in FFM
new feed the beast line upgrade
2 different rebuilt IPs
new pmd and relocation kit
new optic sensor noise filter
checked all grounds
checked all wiring
modified ops relay
Timed and retimed IP with gmtd scan
clear lines, no air bubbles seen
new cps

What am I missing here? what can be causing these codes. I have them on first start, while idle, and while driving. have researched and done everything I have read up on.

 

[vegtech]

Grounds?

Sent from my ADR6350 using Tapatalk 2

 

[JiFaire]

17 and 18 are optical sensor codes. They can be set off by a ground issue, as mentioned; usually happens when the little ground wire is removed from the IP. It's normally on the PMD harness, but some people remove it when they remote the PMD. Not a good idea, it increases the timing length for the OS. If you moved it, get it back on the pump. You say you put a new optical circuit filter on the IP? Most of us just removed the old one when it started acting up and went without one. You might try that; eliminates one more thing. Also, clear the codes and see if you can get them to return by wiggling wires. Doesn't take much to set a code on the OS.

OS issues can be caused by a little dirt or water in the fuel; run some Powerservice silver (pint) and non-detergent HD 30wt (1 qt) in a half-tank of fuel, see if it cleans up.

Alternatively, Optical sensors aren't terribly hard to change out, but you have to get it back in the right spot. There might be a sticky on that around here, I'll try to find it.

Depending on the miles, you might decide that a new IP is easier or more efficient.

Speaking of things I don't know, how about filling out your signature so we can see things like mileage. Welcome, pull up a stump, and join in the discussion... great guys around here!

Jim

*** on edit *** Found it:

http://www.mamut.net/royh/newsdet9.htm

There is also a great how-to thread on IP rebuild from our friend Simon (Bison)

http://www.thetruckstop.us/forum/sh...chanical-aspect-only)/page2&highlight=rebuild

 

[JJ Diesel]

Thanks for the reply. I will fill out my signature this weekend. I have checked all grounds that I can find.
I have not moved IP ground wire. I think I am missing something on my wiring or grounds but can not figure out what. I have tried it without OS filter and same thing.

Tried shaking wires and nothing happens. I have also removed tank and drained and started with fresh fuel. Truck my go 30 minutes or 10 seconds before throwing codes.

My second IP with codes17 and 18.