Diesel Place banner

1 - 5 of 5 Posts

·
Registered
Joined
·
105 Posts
Discussion Starter #1
I noticed this last month but only once in a blue moon.
Today the idle seemed to be up and down even in drive quite frequently.
The fuel filter was just changed last weekend but I don't think it is the filter because it would do this before I changed it. the can hear the roling idle more than you can acctually see the Tach move. Not sure if it is an injector problem because no smoke (unless I really get on it) or loss of power.
No codes are shown.
This is my '05 and is all stock. I do no the air filter should be changed I am in the process of reoiling my amsoil air filter and paper one that has been in there for about 2 months was the original from the factory.
don't think it is bad fuel because I always buy at a hess station and fuel filters are always fairly clean looking with no water.

As I come to a stop you can feel the idle pulse just before the brakes are completely locked.

Hope it is something easy. Any ideas before I bring her to the dealer.
 

·
Registered
Joined
·
105 Posts
Discussion Starter #2
a few things to add it seems to be most noticable when at operating temp. And this morning I heard a strange noise on the highway three times at around 1800 RPMs when I take my foot off the gas it made what sounded like a knock. I hope it is not an injector. I have 63,000 miles on it.
Would an injector throw a code?
It is like clock work now, up, down, up, down, up, down.
I don't like going to the dealer but all well.
 

·
Registered
Joined
·
105 Posts
Discussion Starter #3
Truck fine yesterday on the way home from work but this morning acting up again (not as bad). The knocking noise was there again at 1800 rpms a good way to describe the sound is it sounds just like pilot injection is off only at a lower RPM than 2400 or when ever it turns off.
No smoke seems to accelerate fine and it goes up to 96 mph or 98 mph with out any problems.
Mabey fuel was contaminated.
I fill my fuel filters up with a can of diesel that has been in the shed for about a 1 year. So no priming is required not to sure thats a good ideal anymore.
 

·
Registered
Joined
·
15 Posts
does it idle up and down like a big cam would make it do?kinda sounds like a fuel pressure regulator?
 

·
Registered
Joined
·
105 Posts
Discussion Starter #5
Dealer updated pcm today with the rough idle and low throttle surge update.
I would have to say it did make a little bit of a difference. You only notice a little bit of an uneven idle sometimes when in nuetral or park. Now after the reflash it sounds perfect when in drive or reverse. I still think there may be a little bit of an issue with the fuel system mainly the FPR. Maybe I will try some stanodyne. I used to use Amsoil Diesel Fuel Modifier but haven't been the last couple of months mabey That is how it started doing this.
 
1 - 5 of 5 Posts
Top