U7185 Duramax LLY glitch

[RobertJacob]

I loaded the 65RWHP (std tune) into my 2005 Chevy. I got great performance and fuel economy right away. After driving it for about 500 miles or so I got on it and suddenly the engine wouldn't rev past 2000 RPM in any gear. I pulled off the road, shut the engine off, checked my air intake (which was fine). After I started it up again, it was fine. This has happened twice since then. Any ideas?

[mikel]

Are you running any other aftermarket tuning devices in the truck?

[RobertJacob]

I am using the K&N cold air intake kit but no tuner other than the pedator.

[lccmo]

RobertJacob, Have you changed your fuel filter lately? What code did you get a 1093? If so and you have changed your fuel filter go to one of the larger duramax forums and search of 1093.

[johan]

Lccmo has a good point, i change my filter every other oil change. It could also be a P0101 air flow issue which i have seen with some aftermarket air intakes but that only seems to happen on Cali. emissions equipped trucks.

[RobertJacob]

Ok, after reading the replies and my original message, I thought I should give more data. This problem acts as if the rev limit has been changed to 2000 rpm. The engine revs and cuts and revs and cuts if I try to push past 2k rpm. I have driven another 500 miles on the 85 hp tune and it is just fine.

[lccmo]

RobertJacob

have you checked the codes? Does it do it stock? Have you changed your fuel filter? The 2000 rpm limit sounds like a 1093 code, the usual causes of a 1093 are
1) clogged fuel filter
2) the rail relief valve spring is weak.
3) running a BIG tune - (65-85 isn't big )

Usual fixes for a 1093:
1) change the fuel filter
2) add a lift pump
3) shim the relief valve.

Goto www.dieselplace.com and do a search for 1093.

[Tigermax]

[quote="lccmo"]RobertJacob

have you checked the codes? Does it do it stock? Have you changed your fuel filter? The 2000 rpm limit sounds like a 1093 code, the usual causes of a 1093 are
1) clogged fuel filter
2) the rail relief valve spring is weak.
3) running a BIG tune - (65-85 isnFuel rail pressure relief valve and EGR plate. Just got mine replaced under warranty

[rokbrnc]

I just had this happen as well. I have been running the Diablo tuner set at "65" with an S&B air intake for about a month now. I changed the fuel filter at the same time and it has been running great ever since.

However today when I got on the freeway, it revved to 2000rpm and then surged and would not go back above 2000rpm. I checked the code, and yes it is a P1093 which I looked up the info on from thedieselpage.com forum which says this can also be attributed to sudden changes in atmospheric temperatures. I am in NorCal and yesterday we had a high of 88 degrees, today it's only going to be 58 degrees.

For now I have reinstalled the factory tune, and reset the code. Is this something that I should be concerned about though in the future? Is it a fluke, or possibly related to the use of the tuner?

[Kellen]

I have this problem a number of times. Does it happen when you floor it and then back off suddenly? If so, your truck has a minor momentary loss in fuel pressure and when it catches back up the influx in different pressure trips the code. It is a pain in the ass but that tiny glitch will throw the code. Also after you floor it lay off the throttle easily and that should help.