jetbt25

I have an 01 hy25 truck. over the winter my turbo intermittently stopped working. It started working only on very cold days and would only work two or three throttle ups then it would quit boosting. I have an Edge Attitude so I can watch the boost pressure. And sometimes it would kick in at high pressure like 25 psi and launch me.


But it eventually quit all together. I hear the turbo working it sounds strong.

Does my Edge attitude box have any control over the turbo?

I think I have a wastegate problem since it quit working intermittenly. Does it remain closed and let off boost as throtlte increases or does it start out open and then close to increase pressure?
Also is the actuator boost driven or vacuum driven?

I went under the truck with a light and I can actuate the arm with a pair of pliers and feel the spring resistance and when I let go it returns on its own.

Codes are
PCU
p 0500 speed sensor malfunction
p1693 general faut
0382 intake air heater #2 control circut
0237 boost sensor circuit low

Lot of questions so tx.

jetbt25

I went under the truck where I could see the wastegate linkage and I put pliers on it. Aside from the internal spring resistance it moves freely.
who knows? Maybe the turbo just took a dump.

I wired it closed it there was no difference. 0 boost.

bjytech

I would say its not a problem with the turbo but with the MAP sensor or its wiring since that is what the edge uses to show you the boost pressure and you have a code for it (0237 boost sensor circuit low). Incorrect readings from the MAP sensor will alter the amount of fuel that will be injected as well, possibly lowering performance.

To answer your question about how the wastegate works it starts out closed to help get the turbo spooled and as boost increases it opens up, boost pressure is applied directly to the actuator.

totalloser

^ Yup. Fuel deliver related, not turbo. Diaphragms and springs tend to be pretty reliable, and that's all there is to an actuator. They *very* rarely fail.

I am very un-fond of fully disabling the waste gate on small housing turbos.

SIXSLUG

Could be the edge box also, sometimes unplugging it brings stuff back to normal....especially when throwing codes.

That is a free trial fix before you drop some money on a MAP sensor......

And as far as your turbo stop boosting, that doesn't really happen, the exhaust spins it up and it pressurizes the intake. The only reason it wouldn't work is if it was seized, or if the vanes are gone, which would give other symptoms as well as no/low power, excessive smoke etc.

You may have a blown intake boot, but I am thinking you are defueled due to a bad MAP reading as suggested above....

jetbt25

My buddy is A diesel mech. we did a couple things today. We disconnected the air intake and he did a pressure test on the turbo with an air compressor. Guage accuracy is a little rough but somewhere between 25 to 30 psi the gate opened. And I tried the truck with the gate wired closed and no effect.
Also he had ecode reader thingy deal and we reset it and erased the codes with no effect.

Can anyone pont me in a better direction of how to fix this?

BarryG

As mentioned I would unhook the edge box just to eliminate that possibility as it does hook up to the map sensor at least my juice with attitude and when I had an EZ it did as well. If the waste gate is holding 25-30psi then it is not that. I guess depending on how you pressurized it that should eliminate a major boost leak as well (boots,intake gaskets etc). And also as previously mentioned if the turbo crapped out it would have seized, broken blades or snapped the shaft in which case it would not have worked intermittently. So that leaves the map sensor to check.

jetbt25

It was the Map sensor. 200$ form the dealer only place I could get it without ordering.
200$ and 5 minutes.