Dead Pedal or something else? / Muffler question
 

Dead Pedal
I don't know if I have a "dead pedal" or not, after reading some of the symptoms other guys have it sounds like it could be a different problem.

I just bought this truck, it's a 99 Cummins 4x4 3500 Dually extended cab automatic, and it will drive fine, but sometimes you'll be cruising down the road or accelerating and it acts just like you completely took your foot off the pedal, pushing down harder, waiting, none of that does anything. You have to take your foot completely off, tap it down a bit a few times, then on usually the 3rd tap it will kick back in just fine and run until it does it again. Sometimes you can drive it for 15 minutes in between these spells, other times it's every 30 seconds, doesn't seem to matter if I'm pushing it 10% down or 80% down. Is this a 'dead pedal'?

For what it's worth, the check engine light is on, I'll bring it by the auto store later today and have them scan for codes.

Muffler Question
The truck has a flex pipe going back to a chrome smoke stack (it's *probably* all 4 or 5 inches, I'll have to measure), which someone took out of the bed and welded up underneath coming out in front of the rear passenger side tire, which is fine with me because I don't care for an exhaust pipe taking up room in my bed. The issue is the truck is so obnoxiously loud while accelerating at around 2000 rpms that I can't hear myself think, and my 1.5 year old daughter has to cover her ears. What could/should I do about this the cheapest way possible that won't hurt fuel mileage or performance while making the sound bearable?

Thanks for any advice you can give me! :)

Sounds like dead pedal to me, I would be willing to bet your IP is dying. You need to get a FP gauge and a good aftermarket LP. More than likely you will have to purchase a new IP as well.

Put a muffler or a resonator on it to quiet it down.

Thanks for the quick response, I've heard of the TPS and APPS, but don't know what you mean by IP, FP (Fuel Pressure?), or LP (sorry, new here and to cummins in general :/).

Any suggestions for a good not-too-restrictive muffler? Or will any 4" muffler from AutoZone work?

IP-Injection Pump
FP-Fuel Pressure
LP-Lift Pump

You can try an apps reset.

Most aftermarket mufflers are straight through design, I personally wouldn't buy one from autozone but that is your choice. I would look at Flo~Pro.

Ouch, this is sounding expensive, maybe the APPS reset will fix it, also I'll get the codes and see what they say before I decide anything.

Thanks for the APPS reset procedure instructions, any hints where I would go for instructions on what the fuel pressure is supposed to be where and general diagnostics for the things you mentioned?

Yep, below is a good way to diagnose your VP.

Just got home and measured my exhaust, it's 5", and I can't seem to find mufflers anywhere. Any ideas? :argh:

Thanks for the PDF, I'll give that a shot.

I had the truck scanned and the codes came back:

P0121: Throttle Position Sensor
P0350: Glow Plug

I'm going to borrow an analog multi-meter tommorow to test the TPS like the PDF you provided mentioned, though the behavior it exhibits is much more like the bad VP44 than a bad TPS, which stinks because the TPS is far cheaper and easier.

Also, I didn't think these trucks had Glow Plugs, so what does that other code mean?

It looks like the best way to go here exhaust-wise might be a whole system. I think I have it narrowed down to 3:


Pypes 5" Stainless, $461.99
Flo-Pro 5" Stainless, $484.60
Flo-Pro 5" Aluminized, $364


However, the catch is this truck does have a gooseneck hitch, and I don't know how to tell if these fit with that or not. Any advice on which to choose and whether there is another place I can get them cheaper from or not?

Post up on the site price quote - request a price section you can tell all the vendors exactly what you want and they'll shoot you good prices. Also My truck was doing the exact same thing with dead pedal when I bought it did the apps adjustment and it hasn't happened for a over a year now. Get gauges yesterday. If you want cheap exhaust diamond eye or expandit is usually the cheapest and I've installed several systems on my trucks and friends and families' rigs with no issues, all with goosnecks.