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Failed MAP cause low power?


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30 minutes ago, Me78569 said:

.4 v at idle is way to low.  it should be near 4.5v at idle.

 

Your map sensor is hosed if your truck is giving 4.5v to the sensor.

To confirm I would be looking for 5v on the orange wire-pin A yea? Is there an acceptable range or just a constant 5v?

35 minutes ago, dripley said:

You might be surprised at how much boost you can build even with boost leaks. Take one of the couplings off one day and feel how air the turbo will move at idle. I was surprised. The flow from that will oustrip what I can put in it with my small pancake compressor. The turbo produces a whole lot more volume.

 

Your scanner might read it, but I dont know what have. It does not have to display volts either. It can display psi. You need to see it move when you stick your foot in it. Mine did not move even though I could build about 4 or 5 psi. As mentioned earlier if the ECM does not see any boost it is not going to fuel the engine as it should, hence the weak running truck.

I have an otc genysys. I have managed to seal the boots up pretty good which made a huge difference when giving air from the compressor but I can hear air leaking somewhere but can’t pinpoint it. Kind of seems like the wastegate leaking or somewhere else right on the turbo itself.

 

EDIT the leak is coming out of the wastegate diaphragm/actuator. 

Edited by skyhigh4by
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34 minutes ago, Mopar1973Man said:

Even with the boost hose and bolt missing out of the manifold didn't change boost much maybe lost 5 PSI.20190529_112624.jpg20190529_112612.jpg

So what your saying is a small leak isn’t going to make much difference? The leak in the wastegate actuator bleeds off pressure almost as fast as my compressor can get air in. I assume it’s not supposed to do that? It’s the only leak left as far as I can tell. 

 

Also the boost elbow I have is from an edge ez and it just has a hole right in the side that leaks air out is that supposed to be there? I looked through old parts but couldn’t find the original elbow. 

Edited by skyhigh4by
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A small leak will make a small difference. The bigger the leak the bigger the difference. While your air compresor can compress are 150 psi or whatever yours is capable of, it most likely cannot produce the volume of air that the turbo can. My little compressor will get to150 psi but only produces maybe 3 cfm at 90 psi, could be less. The turbo is capable of many times the cfm of my compressor. A quick, and I mean quick google check said the HX35 is capable of 600 cfm. Others would know better than I. I hope can see what I am saying.

 

The boost elbow that came with my Comp has an adjustment screw in it. It lets pressure of of the actuator so you can build more boost than stock. If yours is missing the screw it is just letting the waste stay closed longer. Do you have a boost gauge? Are you still running the EZ?

 

Dont get me wrong if you have boost leaks, fix them. Your truck will be happier. But for now a MAP sensor is what you need. Fix that then take care of the other stuff.

Just my :2cents: worth.

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Okay thanks. I get what your trying to say about the compressor. I’ll start with the map sensor and go from there. 

 

No the edge is no longer on the truck. It started working intermittently and I ended up throwing it in the trash. With what I know now it could have likely been the map sensor that was the problem and not the edge. I wanted to get a quad anyways but not until I’ve got the truck running right in stock form. 

 

No boost gauge and I would bet the adjustment screw is missing from the elbow. It looks like there could have been threads in there but they’re all buggered up.

 

I cant figure out whether or not the wastegate actuator should leak past the diaphragm or not. I put 25psi into the boost hose and the air just leaks through and out past the rod and the rod doesn’t move. I don’t think that’s supposed to happen?? 

Edited by skyhigh4by
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If you took the EZ off thats why you got the 234 code. The EZ did boost fooling so you can build more pressure. With out it the ECM will defuel the engine once you pass 20 or so psi of boost. I would replace the actuator too. But do the MAP and see how that does and then tackle you other issues. 

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