Normal boost level?

[XOC]

So my boost gauge that wasn't working was due to the other end of the tube coming off the T connection they had put into a hose coming off the exhaust side of the turbo. The connector was just a rubber nipple that pushed back on to the T.

So ... the gauge is working now .. a little. If I floor it I'm seeing around 5 psi on this gauge, and btw I am pretty sure I have the engine tuned to one level above stock on the edge programmer.

What psi should I expect? I had the impression I'd be seeing 10-15. If that's true, and I have some kind of leak, is this like a nightmare to troubleshoot, meaning I should just bring it in to a shop, or should I be able to do it myself?

 

[JRJ04]

im not as familiar with obs trucks...but that seems a little low. i think you should see somewhere in the 10-15 range as well. leaks are not typically hard to find...if you have one 9 times out of 10 its gonna be around the boots. look them over for any obvious cracks or tears and make sure everything is nice and tight.

 

[XOC]

I'm not sure what you mean by boots but I'm guessing you mean where the turbo connects to the intake / exhaust. I don't know if it's my lack of familiarity with diesels, or just general craziness of how it is done, but I took a quick look the other day and I was really surprised to see some of the turbo "plumbing" ... especially this one hose coming off the exhaust side and appearing to dead-end into a bracket mounted to the fire wall on the passenger side.

 

[JRJ04]

not quite...sorry for not clarifying better.

So the boots im referring to (you have a total of 6) are just in front of the turbo. 2 of them are connected to the intercooler pipes near the turbo (1 on each side) and then 2 more are connected where the intercooler pipes connect to the intercooler (1 on each side) at the front of the engine near the radiator. The final 2 are near the 1st 2, but directly below them. These are in between the intake spyder (the goldish looking thing where the top 2 intercooler boots are attached to the intercooler tubes) and the engine.

All of these boots are make of a rubber material that can crack/leak over time.

Hope this helps! If not, ask more questions and I'll dig for some photos!

 

[hheynow]

What psi should I expect?

15 psi max

 

[BJS]

The first place I would start looking is at the connections on your boost gauge. If you have adequate power and are not smoking like a freight train then you are getting more than 5 psi boost to the engine. From the description of the location of the tap you're not measuring boost pressure you're measuring exhaust pressure and possibly post turbo which is a worthless measurement.

The tube should be taped into the MAP line which goes from the passenger's side intake plenum to the map sensor on the fender just above the a/c evaporator & blower box.

As for boost leaks there are only 3 (likely) places on an OBS, the v-band clamp at the turbo outlet, and the two boots on the intake plenums.

stock unloaded you will get no more than 15 psi boost, with a load it is possible to get up into the 20's, light programmer will get you a bit more boost all around.

 

[XOC]

Thanks guys. I have a feeling I may have mistook the anatomy of the plumbing on the passenger side. I'm going to take a much more careful look and also try plugging the meter straight onto the T if I can open the throttle manually.

... Is there an easy way to access the throttle cable so I can rev the engine while I am standing next to it? If so, can someone explain where I should find it?

 

[95_stroker]

... Is there an easy way to access the throttle cable so I can rev the engine while I am standing next to it? If so, can someone explain where I should find it?

There is no throttle cable on a PSD, this was the first diesel engine in a light duty pickup that was 100% fly by wire (computer controlled), since this the other two have followed with the the 24V Cummins and the 6.6 Duramax. But the 7.3L PSD was the first.

In the pic below you can see the tube coming up off the passengers side intake and going up to the MAP sensor, you can also see where my TEE is tapped into the line just prior to the MAP. That is where you need to be installing your TEE.

 

[95_stroker]

Hope this helps! If not, ask more questions and I'll dig for some photos!

Jourdan, the 94-97 model year PSD's were not inter-cooled, hence they also have a non-waste gated turbo and came stock with the wheel that all the SD guys want to put in their compressors.... aka the WickedWheel...

 

[JRJ04]

whoops forgot about that!