gmctd

bigredBCS - it doesn't hurt anything if the hose is plugged, long as you have Boost and EGT gages installed - and pay attention to them.

Also, low Boost could mean more smoke, but the ECM senses Boost via the Manifold Air Pressure sensor and limits fuel when Boost is low, reducing smoke.
The AFC does that in the 12valve trucks

And folks, like charliez posted, do not even put your hand across the intake of any Diesel engine while it is running.

While a Diesel does not, for all practical purposes, develop vacuum in the intake - there are no throttle plates to reduce the headlong rush of atmospheric pressure into the cylinders - your hand is not nearly rigid enough to manage that task.

You could be severely injured in that event.

jrs_dodge_diesel

Thats almost correct.

A gas engine creates vacuum because of the throttle plate. The throttle plate (whether its in a carbed or EFI engine) acts as a restriction, when you have a cylinder trying to suck in air against the throttle plate you end up with negative pressure (AKA - vacuum) behind the throttle plate. If you ever notice on a gas engine the vacuum lines are attached to the intake after the throttle. As the throttle is opened less vacuum is made since there is less restriction in the intake. Even turbocharged gassers maake vacuum. As long as there is a throttle on an engine it will make vacuum. Gas engines require a throttle to control the amount of air entering the engine to maintain 14.7:1 air/fuel ratio (stoiciometric).

Diesels on the other hand, do not have a throttle since diesel engines do not need the air flow to be controlled. Remember, diesels are not limited to a specific air/fuel ratio. Take our Cummins engines for example. The intake starts at the filter, goes through the turbo, intercooler, intake manifold then to the cylinders. Nowhere in the intake is there a throttle. At idle if you measured the air pressure at the intake you would read atmospheric pressure. This is why we need an auxillary vacuum pump.

Hope this helps clear up the confusion.

mr T

its not an issue..the previous owner was just having some fun and plugged the wastegate so that he would have no limits on boost....the amount of fuel dictates the boost levels...if ur close to stock dont worry about it...but do get gauges soon..

ps i have my wastegate plugged off

linetrash75

Are the 03's like 98.5-02 where if the ecm sees overboost it starts defueling if so you will be losing power when making more than factory amount of boost. Do yourself a favor and go to your local hardware store and get a hose nipple that fits the turbo and the hose, then you have nothing to worry about.

Jed

jaybone

Mr-T, Thanks. Thats all I was looking for. The truck is still basically stock, or so I assume the only things different are an EGT guage and straight pipe exhaust. I saw somewhere on here dont leave it(waste gate hose plugged) or your blow your head off the engine if you over boost it. Being stock and hearing all the above responses, does not sound like thats possible if the stock ECM is in control of the fuel system. I just never see any black smoke out if it...Now I think I understand why. Truck runs fine on hwy and the trip computer deal says its getting 22mpg @ 65 mph.

jaybone

Quick ? If there is an overboost condition will the pressue itself push open the wastegate?

mr T

no ..if its plugged its plugged....so u mentioned u have an egt gauge on it?...get urself a boost gauge as well so that u know what ur running...plugging the wastegate is a common mod that u probbaly would have done yourself a year down the line (or less )

gmctd

Exhaust pressure will blow open the wastegate at around 35-40psi - Boost pressure assists exhaust pressure to open it at around 18-20psi when wg actuator is connected to the compressor as normal