Engine/Transmission (1998.5 - 2002) boost psi

[SAndreasen]

What boost psi should I have at cruising speed at 1800 rpm .?

 

[B.G. Smith]

With no load on level hwy. not much. maybe 5 or 6 lbs. bg

 

[SAndreasen]

I'm only getting 0 maybe 2 psi

 

[mrmurphynv]

2002 with in-tank Dodge upgrade after failed boost/injector pump. 10psi at idle 8psi on highway as low as 6 under load on hills

 

[JR]

I assume your talking lift pump pressure? That's about all Your going to see out of the OEM lift pump.

 

[JR]

I'm only getting 0 maybe 2 psi

I believe you have a boost leak somewhere.

 

[SAndreasen]

Fuel psi is 13 down to 7 pulling heavy to the floor . Have checked for boost leaks can't find any

 

[JR]

Did you use a boost leak detector? WIthout One of them it can be difficult to find a leak. At your pressures I'm thinking you have one.

Are you seeing 0-2 psi at 1800 rpm driving down the road and not just idling the truck up to 1800rpm in neutral? There is a pretty big difference between the two.

 

[SAndreasen]

I used a can of ether if you don't believe me it works make a small entry for it and spray and see what happens I make 24 psi under load it will make 4 psi at 3000 rpm in neutral

 

[cerberusiam]

If it makes 24 psi under hard htrottle there is likely no leak. Low load cruisng 0-2 psi is not unusual. Boost is load dependent so speed and air make a difference.

 

[SAndreasen]

Thanks for the reply that's what I was hoping but wanted to get peoples opinion on here

 

[Bob V]

Might be worth checking with a different gage.

 

[bry1216]

MAP/Boost Sensor is dependant on your altitude

I recently had a MAP/Boost sensor failure. The attachment is for the old failed sensor and new sensor at 3,000 feet. This sensor has a sealed area on one side of an electronic component (strain gauge, potentiometric, capacitive, etc..) and atmosphere on the other side during ohm measurements. Install it would be sealed area on one side of electronic component and intake manifold pressure on the other side.

Cruising at 1800 rpm would be relevant to altitude, load and road levelness. I would consider it normal boost pressure for cruising on a level surface with no load.

Spraying ether on an intake with at idle (very low pressure) would find any leak, but a manifold under pressure it would be rare to find the leak. A manifold under pressure with a back streaming effect can cause the ether to enter at a molecular level (very small).

 

[SAndreasen]

Thanks for the info .

 

[Bob4x4]

I would not use ether to find an intake leak,something much less volatile would make more sense and be safer if you feel the need to go that route