i got no boost. any ideas?

[8608 Advanced Member Find all posts View Profile Close 8608]

after a couple of hours on the net tonigt with not luck, i'm asking here.

it seems as though i have no boost, as a result of the stepper motor not working. i'm assuming.

the prado is super slow, like a 2.4L diesel hilux, and won't rev any higher than about 2000-2200rpm.

scan gauge shows -3.5 psi boost, and the stand alone boost gauge shows zero.

free revs on the slow side, but will do over the 22oorpm under load. top speed is about 80-90km/h.

it just feels like a NA trying to push 2.6t on 33"s.

i have checked the turbo control module under the glove box, which seems ok. the scanner doesn't read/log any falt codes, so i can't narrow it down to anything.

nothing around the turbo seems odd, and no wires are melted or unplugged.

i've disconnected the batteries for about an hour, then re-connected them in hope that would have reset things. still no different.

any help is appreciated, or if there are any other things for me to check, let me know.

thanks in advance.

[photoprado Avid PP Poster! Find all posts View Profile Close photoprado]

Sounds like its in limp-home mode. Are you getting any unusual warning lights on the dash?

Disconnecting the battery for a few minutes should have fixed it.

[8608 Advanced Member Find all posts View Profile Close 8608]

No lights on the dash at all. Not even check engine.

I've taken both batteries out overnight anyway. Actually charging them with the c tek while they are out.

It was a sudden loss of power, but no other symptoms.
I thought it was a fuel issue to start with.

[peril Senior Member Find all posts View Profile Close peril]

Its a fuel issue I agree, fuel is managed by the computer, likely the limp home mode or something reducing fuel in a similar way. Perhaps the throttle actuator is not functioning as it should?

I'd expect to be seeing warning lights, so this is a strange one? Watching and waiting to see what eventuates.

[DieselSmart Junior Member Find all posts View Profile Close DieselSmart]

there is a boost line that goes from the map sensor to the intake manifold, usually joined in the middle by a piece of plastic hardline. prados and hilux's are notorious for blowing this line off. I have included a picture for you that circles where the line starts and where it goes to.

This will cause the exact issues you are talking about as I have seen these come off many of times on the dyno and while driving the cars..... I would be checking this first

Please let me know

[pjorek Advanced Member Find all posts View Profile Close pjorek]

that's exactly what i was going to suggest: a vacuum line somewhere or turbo actuator?

[matt150 Avid PP Poster! Find all posts View Profile Close matt150]

I diagnosed Joeys 120 with the same is. The lines split or fail around the hose clamps if a bleed off tee has been fitted. On the drivers side, look down at the turbo and see if there is a small rubber hose between the turbo housing and the wastegate, that's usually the culprit.

Piss easy to fix..

[t303 Senior Member Find all posts View Profile Close t303]

Have you refuelled anywhere different/suss lately? I usually start with the basics; ie throw a new fuel filter on it and split the old one for inspection.

[8608 Advanced Member Find all posts View Profile Close 8608]

i checked the prado this morning, and found the small hose from the manifold to the inline filter had split. i suppose i had a womans look yesterday.

i've had the hose come off before, and i did check, only now it was split on the inside. the short hose does more than a 90 degree bend, so it was hard to see. it is also hidden under the comling.

thanks heaps for all the help, and no doubt this will help all future prado pointed find their lost boost again.

cheers again fellas.

[D4Dforme Senior Member Find all posts View Profile Close D4Dforme]

Will a bigger hose give us more boost?.........cheap mod?......LOL

Dan

[DieselSmart Junior Member Find all posts View Profile Close DieselSmart]

Will a bigger hose give us more boost?.........cheap mod?......LOL

Dan

If giving your car more power was that easy, we'd be out of a job hahahha!

I strongly suggest all PP members change this boost line as 90% of D4D owners will experience this problem during the life of their car, not all the time you will be able to repair it and may find yourself stuck in the middle of nowhere


Glad to hear it's fixed

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

scan gauge shows -3.5 psi boost, and the stand alone boost gauge shows zero.

.

How do you read boost on the scangauge? Is it just the MAP reading?

I must try and put this hose problem in the old memory bank in case it happens to me.

Cheers Andrew

[8608 Advanced Member Find all posts View Profile Close 8608]

How do you read boost on the scangauge? Is it just the MAP reading?

I must try and put this hose problem in the old memory bank in case it happens to me.

Cheers Andrew

http://scangauge.com.au/wp-content/u...urbo-Boost.pdf

you will have to configure it to your altitude.

[roadblock Junior Member Find all posts View Profile Close roadblock]

I reckon I’ve encountered the same issue today. Heading off on a trip towing our van. Was just thinking how well the prado was pulling then heard the pitch of the turbo change to an unfamiliar note. Lost most of the power so I pulled up. A quick inspection under the bonnet and check for codes on the ultragauge showed nothing untoward. Proceeded with the climb up Eton range during which we were flat out getting above 20kph. Pulled up again, shut down and restarted. Power returned for about 15km before losing power again, accompanied by CEL, flashing 4LO and TCS lights. Checked codes again and had P0299 - turbo underboost. Cleared the code, shut down, restart and power back to normal. After another 15km the same thing happened again so we called it and turned for home. Happened another 3 times on the way home even ‘nursing’ it. I’m thinking stepper motor issues as when it recovers the turbo seems to be boosting as normal. Will be calling Baileys first thing Tuesday.

[pjkilby Lurker Find all posts View Profile Close pjkilby]

I reckon Ive encountered the same issue today. Heading off on a trip towing our van. Was just thinking how well the prado was pulling then heard the pitch of the turbo change to an unfamiliar note. Lost most of the power so I pulled up. A quick inspection under the bonnet and check for codes on the ultragauge showed nothing untoward. Proceeded with the climb up Eton range during which we were flat out getting above 20kph. Pulled up again, shut down and restarted. Power returned for about 15km before losing power again, accompanied by CEL, flashing 4LO and TCS lights. Checked codes again and had P0299 - turbo underboost. Cleared the code, shut down, restart and power back to normal. After another 15km the same thing happened again so we called it and turned for home. Happened another 3 times on the way home even nursing it. Im thinking stepper motor issues as when it recovers the turbo seems to be boosting as normal. Will be calling Baileys first thing Tuesday.

Old post, just curious what caused this to happen to you roadblock?

Cheers.