Hey all,

I just wanted to post about an issue I'm having with my '03L w/ 22.5k miles. When I get into the boost the truck starts to shudder and not accelerate smoothly. It mainly happens at 7psi and higher. The sound is like the sound one makes when gargling water, but mechanical in nature.

I also thought our trucks had 8psi stock and my gauge is going up to 10psi, is that ok? My only mod is the K&N kipk, and everything is tight, no check engine light.

I just put on my nitto drags and can't even test them due to my truck running like this. I tried it with a/c on, off and heat on/off no changes to how it runs.

Can anyone chime in?

Thanks,
Dan

 

Sounds like it's time to change the fuel filter.

 

1. check all those vacuum hoses that are on the engine, look for disconnected ones and hairline cracks

2 fuel filter

3. Clean the MAF sensor with non-resdue leaving behind contact cleaner (electronic cleaner, brake cleaner)

 

I'll take care of the fuel filter tomorrow, and clean the MAF sensor too, hopefully that'll solve the problem. I didn't see any cracked/broken vacuum lines when I installed the K&N recently, but I'll double check that also.

Thanks!

 

Check the vacuum line coming off the top of the EGR. My truck had the same deal after the intercooler swap. Thats what it ended up being.

 

UPDATE:

Just changed fuel filter, no difference, didn't help.

I tighted all the clamps for the K&N and checked for vacuum leaks - didn't find any though.

Any other thoughts?

 

It could be the MAF if there was too much filter oil on the K&N. Clean it carefully with contact cleaner - might help.

I had the same thing happen on another vehicle, installed the K&N and the MAF got oily from the filter, cleaned it and it ran fine.

 

Dan,

You should change your plugs, it is possible you may have gotten a bad tank of gas and you may have deposits on the plug or plugs, you may have even lost a tip to a plug. We have seen that here on the dyno a few times. We use TR6 plugs and gap them at approx .038.


Anthony@JDM

 

Check you plugs. Could also be a bad coil pack... pay particularly close attention to the rear most, passenger side coil pack. Those are known to go out due to a slight coolant leak from an improperly tightened hose above it.
Isn't this still under warranty??

 

Ya, it should still be under warranty, but I was hoping it'd be something cheap and easy for me to handle. Plus, I didn't want to get any crap about the K&N from them.

Dan

 

Plugs is the very first thing I'd recommend looking at / swapping.

BTW: You have got to be joking? Right? I'd say that with the right tune and plugs you should'nt sweat it til you see 18psi.

Rich

 

Dont worry about the K and N... or put the stock one back on... 10 minutes top.... you will waste more time then it is worth for you. That is what the warantee is for.

ON a side note, I had the exact same problem and tried everything everyone allready said. Took it in to the dealership, and it ened up being the fuel pump.