What is a P1093?

[MaxACL]

My SES light has been on for about the last six years and I've come to live with it. The EDGE chip causes multiple codes such as:

P 0106, P 0107, P 0341, P 0380, P 0489, P 2141, P 2144 and P 1093.

I can disconnect the EDGE and soon all code go away. But lately (last several months) the 1093 will come on as soon as I hook up to a trailer. It will go away after I disconnect and stay off till I hooked up again. (no EDGE chip).

I change fuel filters often, refuel at the big truck stops, use PS additive and even changed the entire fuel line from the tank to the filter head. This was done because of a "crimp" in the line at the firewall. By the way, the new line was shipped from GM in a box that was too small and the new line was bent over and crimped in the same spot.

The fuel mileage isn't bad, 11 towing, 16 empty, and the performance is great. The onset of the 1093 code will happen at the lower RPMs when I am going from....say 3rd to 4th or 4th to 5th, etc. After entry to the higher gear and the RPM is low. Am I starving my engine of fuel?

Mike

'02, 315,000 miles, ZF6 and all stock except for the EDGE.

[Kennedy]

There are 3 general causes that come to mind:

1) Insufficient flow. A weak pump or regulator or loaded fuel filter/restricted fuel supply. We don't see a lot of pumps go and regulators typically show odd operational characteristics like surging etc.

2) Programming. Harness boxes like the Edge give fuel to the engine without the ECM knowing so it cannot make informed decisions regarding regulation. It's also common to see this on 2001 models due to factory programming issues.

3) Leaks. This is generally too much return to tank via injectors leaking. Could also be air inward, but this generally creates starting issues as does high injector returns.


Adding a good lift pump setup goes a long way to helping the fuel system out and is definitely worth considering.

[MaxACL]

John,

The last visit to my mech in Texas he said the computer wanted x psi and was only getting "less", thus the SES light and code. What can I suggest to my guy in Texas? He's an excellent mech but doesn't see too many D'Maxs.

By the way, I could use your insight on the other post on 2500/3500 light truck... "Mixed Parts"

Mike

[MaxACL]

One other thing John... I just had both fuel lines replaces from tank to filter because of a crimp at the fire wall.

Mike

[More Power]

A 1093 can be caused by a plugged fuel filter or an airleak in the fuel supply (fuel lines, fuel filter assy, improperly installed fuel filter, or a leaking fuel hose somewhere on the engine).

Can you pump the fuel filter priming plunger after running the truck for awhile, and having already bled the air sometime earlier? If so, there's air getting in somewhere.

Jim

[Kennedy]

The first step in diagnosis is to measure fuel filter/system restriction. We have a handy gauge for this that no Dmax owner should be without.

Skipping ahead to the remedy, I'd suggest adding my twin lift pumps to help push the fuel up to the IP. Should help or fix the problem, and if not you are still doing a good thing for the engine.