diesel fuel pump adjustment help please

[gqt]

It's the stock waste gate. All I can think of is it got tuned with the blocked exhaust so taking the exhaust off has resulted in alot of boost. As like I said with the controller on it was fine before I took the exhaust off.

[HammerBuilder]

Mine was stock & used to open wastegate at 11psi on 2 different brands of guages now with pump adjusted I run 13psi allday everyday but when cruising still only sits round 7 or 8 on the highway as said I run 33x10.5x15's bfg muds all time with bout 38psi in them if that makes a difference (thats bitumen pressure)
Oh yeah I also just re-read your post & no there isn't an adjustment on the pump to lower the boost it is controlled by the wastegate diaphram.
On the pump there is a TPS but this also is only to help in delivery or adjustment of fuel output.
Also did you fit the boost controller as some have a little ball n spring on the turbo pressure side & these also hold wastegate shut till boost overcomes this little spring tension which what you are now describing as won't go bellow 15psi so check if it does & take the ball out & give that a try I had to do this on a mates that runs a Turbosmart Boost T, now is fully adjustable right down to standard boost.

Cheers hope this helps this time.
TonyD

[robbo0001]

Mate...I have saved this thread to my "favourites"...Currently running 33s on a 2.8TD with boost and pyro guages fitted. (by myself)
To MY knowledge (second owner) no engine mods...currently max 13 PSI boost and never hit more than 450 degrees C on the pyro. (with no engine/fuel changes by myself)
Looking at winding down fuel a "tad"...if required I will fit a manual boost controller to sdjust.

Highway at 110km...contant 12-13psi (back off accelerator pedal, immediate boost drop)

[97_gq_lwb]

Well bypass your controller and give it a try.
No matter what you do to the fuel the wastegate should open up at a set psi .
So something is faulty.

[gqt]

I'll take the boost controller off tonight if it doesn't rain and again and see what happens. It's just a cheap eBay job manual boost controller. But yeah it's only happened since dropping the exhaust. And I know freeing things up can raise boost. But shouldn't be to this extent.

My boost gauge is in bar. Playing with the diesel pump I can change it slightly on the fwy. Lowest I can get it to sit is 0.7 bar at 110 on the 35's with only a quarter tank of fuel and one passanger. Adjusted it the wrong way the other day and it was sitting on 1.0 bar the same as above with quarter tank and one passanger not towing.

[97_gq_lwb]

Yeah really all it can be is that or your wastegate actuator not working is it an adjustable actuator arm ?
It Can be the rod has been bent for higher boost.
Or they sometimes space the actuator mount out with spacers as well.
Could even be a replacement actuator for higher boost as well pretty hard to tell they look the same as stock just open up at a higher psi.

[HammerBuilder]

Mate...I have saved this thread to my "favourites"...Currently running 33s on a 2.8TD with boost and pyro guages fitted. (by myself)
To MY knowledge (second owner) no engine mods...currently max 13 PSI boost and never hit more than 450 degrees C on the pyro. (with no engine/fuel changes by myself)
Looking at winding down fuel a "tad"...if required I will fit a manual boost controller to sdjust.

Highway at 110km...contant 12-13psi (back off accelerator pedal, immediate boost drop)

Yep robbo0001 the later intercooled did run 13 like yours is, the early 97 & before were not intercooled so run lower boost so maybe gqt's turbo was updated to a gu unit as they are all bolt on bits even the intercooled intake manifold is different.

gqt keep us informed as to what you find & how you go...
Cheer TonyD

[robbo0001]

Thanks Hammer....
I just learnt something new...and thats always good.
I always thought the GQ 2.8TD was the same engine in the GU 2.8TD....happy to work-out the GQ 2.8 is not intercooled OEM.
Glad to hear 13 psi is stock on a GU...and I don't need to worry about overboost issues yet!
Greatly appreciated mate.

EDIT... not a thread hijack..my apologies Qqt

[HammerBuilder]

Too easy robbo I always try to help & I am always ready to listen n learn

Cheers tonyD

[gqt]

No concern on hijacking mate. I'm here to learn anything and everything I can

So found out where my fuel was when I got the car wouldn't of been standard. As had it wound back to there and just found out over the weekend that it was still blowing a heap of black smoke out from under it. So wound down another quarter of a turn, no more black smoke now

Boost wise it's down to 0.6 bar at 110. Can actually fully rev out in 1st, 2nd and 3rd now. 4th hits overboost at 3,200rpm now up from 2,800rpm. So I'm quite happy with it now. And it's doing heaps better on the economy side also still have not removed the boost controller yet though. Will still remove it to see if it makes a difference.