I have a few questions for you guys. I have noticed what sounds like injector noise, mostly at moderate throttle 1500-2000 rpms. You can see my mods in my signature, I have done the regulated fuel mod recently. Now, I'm not sure if the noise is worse after that or not. It's also very cold here right now, but I keep my truck in a heated garage and it's still loud even after it has run for a while. I've also done the HPX mod and at Idle, it sounds very good. Also sounds pretty good at highway speed and under hard acceleration. The truck also runs good, plenty of power, just some noise.

When I opened the hood and ran the fuel pump, I heard what sounded like air passing through my new regulator. It really doesn't sound right. The needle on the fuel pressure gauge also "twitches" some leading me to believe that there is some air in lines. It's worse when it's running, but I don't know if that's just vibration of the gauge. I haven't pulled the quick connects yet, plan to do that tomorrow. I'm going to have to look, I didn't see where the fuel lines went into the tank on my Excursion.

I thought it might be worse since it's so cold and may have more suction with the cold fuel. I also thought the fuel pump may have problems, but not too sure. The only reason I say that, is I ran a couple hundred miles with a really bad fuel leak and thought it may have stressed the pump. The apparent sound of air passing through the regulator has leaning toward an air leak. Could I really be getting that much air through the quick connects? Guess it could be an injector, but no smoke etc.. Here's what I'm thinking, with the fuel mod there is an increased flow, that combined with the cold temps and thicker fuel is causing more air to be pulled in through the quick connects. Does that sound reasonable? What do you think? Thanks guys.

 

Yes. I would do the in-tank and pre-pump mods. That should rid your system of all air. Kwik said that he noticed a bigger difference after he did that than he did with his air bleed system. I did my pre-pump & in-tank mods right around the time I did my regulated fuel system, so I can't comment on which helped more. But she purrs like a kitten now!!

Look at some of these photos. Notice how much air is in the lines?? That's all from the quick connects. Check out the whole gallery. It's from a hutchinaugusta, which is where we get the term "hutch mod" for the in-tank and pre-pump mods. Here's the gallery: http://community.webshots.com/album/32303501JuYKPH

 

Thanks JT. I have seen those pics before, I should have went back and gave them another look. After looking at he pics of the aerated fuel, I can see where it would make the noise I'm hearing at the regulator!

 

hey guys,
what years are affected by the "cackle" according to everyone's knowledge? I'm thinking that I'm hearing the same noise of a hammer hitting the block but i'm not sure. I own a 99 sd psd. Every so often it seems to quiet down regardless of the tank level.
I'm just curious to see if I'm imagining noises. Or if its a exhaust leak or the "cackle".

 

To add to the earlier question is if it might the fuel at the place where i'm purchasing the fuel.

 

I doubt it's the fuel you're buying. It should happen on your 99. Same fuel system design.

Listen to some of these sound clips to see if it's what you're hearing.
2 with cackle:
http://jtharvey.home.mchsi.com/PSD/movingcackle.wav
http://jtharvey.home.mchsi.com/PSD/stationarycackle.wav
One without cackly:
http://jtharvey.home.mchsi.com/PSD/nocackle.wav

 

I did the in-tank/pre-tank mods, and haven't yet done the regulated fuel return. I've lived with it that way for well over a year.

That mod eliminated the loud injector noise at idle and at mid-rpms, part throttle. I also picked up about 1/2mpg. I will do the regulated return within the next six months. If I notice a big difference, I'll report it. Actually, whatever I experience, I'll report it.

I looked at the situation and thought eliminating the source of the air might be more effective than returning it once it was in the system - that is why I did the tank/line mods first. That, and it was cheaper.

 

yes i agree with you arninetyes. i did the prepump mods and it helped a bit, but i plan on getting a reg. return fuel system in because i still hear alot of fuel problem noise when under a slight load at 1250-1750 rpm. i dont like it, and i hope the Reg. return fixes it. but hink, i would get that intank/prepump mods NOW and see if it helps the air situation.

 

I'm going to try to get the fuel lines/quick connects done today. I have a full tank, so that part won't happen for a while. Thanks.

 

Hmm, I am just not mechanicly incline enugh to do the in tank mods. Are there any places that sell a kit or onything that can correct the fuel cackle issue? At this time I am not experienceing any cackle, but I also keep the fuel tank fuel as much as possible.

 

If your quick disconnects on the pre-pump lines are leaking air, a full fuel tank won't help.

Yes, there are kits that simplify the mod - but believe me when I tell you that it is still a lot of work, as you have to pull the fuel tank to do it. Mine has a 38 gallon tank. Even empty (or with only about 3 gallons left in it) it was a handful.

Still, it was well worth the effort.

 

Just listened to jtharvey's downloaded sounds.. My PS is emitting the same sound, I was beging to think I had a rocker/valve problem. In the thread, someone said they were seeing foam/bubbles in the catch pan under the filter drain tube.. Did they kick the drain valve open after Key-on or is there another quick procedure?

 

Hink I've noticed the same noise at 1500-2000 rpm as well even after doing all that work.
What I've noticed in the past is the motor will sound great while I'm pulling the trailer and for about a week after I get back home from workin' the engine nice and hard. Then gradually the injector rattle begins to return. The engine sounds great at idle and WOT all the time. Just at that mid range RPM and half throttle it doesn't sound so good.
At this point I'm of the opinion that the only cure is a new set of injectors. I think the nozzles have been worn away by the 50,000 miles of pre-mod foamy fuel to inject. The problem is not bad enough to want to spend $200.00+ per injector for some new Alliants. I'd rather give some of that money to Jody Tipton.

 

Now there's no question where Kwik's heading.........givin' in to temptation.

 

I just meant that the tank was full so I wouldn't be able to drop it right now. I will do it when the tank gets low. I can't even get to the fuel lines at the top of the tank. I have an Excursion and the tank is behind the axle, It also has a skid plate so there is no good place to reach above the tank. I need to look at my shop manual and get a better idea of what is going on. I did get the quick connect at the pump changed, the fuel going through the regulator sounds like it has much less air!