01 6 speed

No power, no smoke at tail pipe

New fuel filter, brand new lift pump

15 psi at idle, no check engine lights or codes

 

 

Test for boost leaks

Haven't found any with soap test, will check with positive pressure and air compressor tomorrow

If it was a boost leak wouldn't I be blowing black smoke but the ton....

This thing won't smoke at all, and can't get out of its own way....

If you have stock fueling then I wouldn't expect smoke.

I have an edge ez box, and it was smoking before under throttle... Hence my concern

No power, not smoking

And yes I have removed the box to test,

Problem remained

In my mind no power equals not enough fuel and Air, if there is no smoke and no boost leaks sounds like it's under fueled,  since fuel delivery is mostly electronically controlled on this truck, in my opinion problem lies within VP or ECM. I suppose that could be mechanical problem inside VP, something not letting fuel through. All just speculation of course, maybe try double dose of two stroke in case something seized up in VP.

Are there any sensors that could cause this, without throwing a code or CEL?

Oil pressure sensor maybe, check for 5 volts I belive.

Edited December 14, 20168 yr by Dieselfuture

Oil pressure won't do it. 

 

Your map could be stuck reading low.

 

 

I would agree about no boos tleak if you have an edge ez

Do you have access to a live data tool? You can see what all of the sensors are reading with the tool. If the MAP sensor is stuck at zero, it's not going to fuel much at all. 

Waste gate stuck open? You could put 20 or so psi on it and check. I dont think that would set a code.

Yesterday I cleaned the map sensor, drove truck a lil.... Still no power

This morning I started truck to warm up for work drive and when I drove off..... Suddenly the trucks running better than ever... Boost reading on my map sensor again

So you weren't reading boost when it had no power?

Excessive boost will cause limp mode. If you boost is exceeding 19-20 PSI it will trip limp mode without tripping a code. If you do manage to pull hard enough it will trip P0234. I've ran several times with my boost elbow and no boost fooler and it just falls on its face without tripping a code. It relies on the limp mode more so. I would inspect the turbo wastegate. 

 

1 hour ago, Cueballtech said:

Yesterday I cleaned the map sensor,

 

Cleaning the MAP sensor will not fix anything either. 

It wasn't reading any boost on my map sensor... Now it is...

I'm thinking the map sensor is faulty but it never tripped any codes

Yea it can get stuck reading "0" and the truck is just a pig.  

 

 

I would plan to rpelace the map, as Mike said, typically cleaning doesn't do a whole lot.  But if you are like you will just run it and forget and hope haha.

Cueball,

 

This is one of the main troubles with the OBD II system and the sensors that report to it.  ALWAYS remember: the computer THINKS the information is TRUE, even if the data makes no sense.   The computer only checks to see if the sensor reports a value that is out of a specified range.  If the computer sees the value in the proper range it makes the ASSUMPTION the information is true.  It does not use logic to relate that information.  (ie,  it does NOT go "hey we are at 90% load and have been for 5 minutes, why has the coolant temperature not changed or going down?) 

 

So a map sensor that reports a value in the normal range and is stuck there, even though it should "know" that the range should have changed with engine load, it says everything is all okiedokey and therefor no CEL or codes are set. 

 

This is why it is so important to let the human brain see the actual values and apply logic to the values.  (now i will get on my horse to say this is why all these points and ranges should be easily found and verified.  The OBD system is not very self diagnostic.) 

 

HTH

 

Hag

That what's known as failing within specs. I've seen rare times of that happening.

Yet again though it's weird because it was showing on the torque app as no reading.. Not 14.7 which is atmosphere...

That's what had me confused... I'd think if the computer saw no reading from the map sensor it would trip a code.... Like it did when I unplugged it trying to figure this out......

Our truck report an value around 28.6 to 37.7 on MAP sensor.