Boost issues

[srichard]

I noticed yesterday that the truck doesn't boost past 32psi any more.

When I installed the Quad Race box, it would hit over 40psi in all 3 setttings (60-100-130) but now seems limited at 32psi.



Before I call up Quad, I was wondering if there might be anything else I should check out?



thanks in advance.

 

[JCleary]

First thing they'll tell you at Quadzilla is to check all the connections.



They mean unplug and re-plug all the connections: Rail, MAP, Com port, box, switch. They recommend using dielectric grease on the engine related plugs if you're having issues. They may also ask about the light on the module. Supposedly it has a self-diagnosing feature.



After that, they'll tell you to send it in so they can test it (if your problem hasn't been solved).



They'll probably hook you up with a new wiring harness. The boxes have a low, as in super-low failure rate, but the harnesses seem to have issues.



You may want to ask this in the 3rd gen forum, you may get more responses.



If it isn't a problem with the box, maybe you have a boost leak somewhere?

 

[srichard]

yeah, I *had* to do some testing this morning... and I found that actually it seems like the boost is coming on slower.

In 2nd gear, it won't get any higher than 32psi, but in 4th or 5th I can get it to 38psi (eventually).

So that tells me that the Quad box is still doin' its thing with the boost fooling.

I recently installed the Scotty 5 - so maybe I have not tightened a clamp enough? would an air leak on the intake side cause a boost decrease? or if the filter was over-oiled, would it cause enough restriction to affect boost up speed?

 

[Graphic man]

you may also have a boost leak..... check all boots and make sure there tight



fuel makes boost, so it also could be the box de-fueling, did you get any codes? maybe a over boost code?

 

[srichard]

nope no codes, but the truck does feel slower. I'll have to check everything for leaks. thanks.

 

[JCleary]

Check to see what color the light is on the box. If the switch is bad or disconnected, it will default to the 60 setting/green. If there's no light, then there's no extra power.



Sounds like you may be stuck in the "off" position.

 

[srichard]

nah, the box is on. I can see the LED while driving, so I know the box is on the right setting.

I checked for codes again, nothing.

I looked unde the hood and visually checked the hoses and intercooler, but didn't see anything obvious like cracks .

Any idea how to find a boost leak?

thanks

 

[srichard]

you may also have a boost leak..... check all boots and make sure there tight



fuel makes boost, so it also could be the box de-fueling, did you get any codes? maybe a over boost code?

I am starting to wonder if myabe my fuel pump of injectors could be having problems. I mean, the truck feels like it's running out of steam on the top end, but the low to mid range seems ok.

I put on the box when the truck had about 4000 miles, it's now 2000 miles later, and I wonder if my fuel delivery is just not keeping up.

It's frustrating that I am not sure how to go about trouble shooting it. I'm pretty experienced mechanic when it comes to gas engines, but I am still learning about diesels...