Turbo Boost lag ?

[june]

I have a 2002 Auto 3lt GU Wagon, engine mods : 3inch S/S Taipan Exhaust, Taipan catch can, Southern cross intercooler, EGR blocked, Steinbauer Chip,Boost and Pyro guages, heavy duty valve body in auto, manual lock up torche convertor, auto temp guage. Plus other mods. We are travelling , towing a 3 tonne caravan. Turbo looses boost, only sometimes, when going down a gear to climb hills, when i lift my foot off the gas, boost picks up, without further problems,it has only started doing this since EGR has been blocked. My question being, has anyone else, had this happen ? or does anyone have a suggestion as to why this is happening ? Appreciate your thought on this.
Thanks Dave

[BOWZER]

hi mate i suggest you look for a leak in the cooler piping, also have you fitted a dawes valve?

[threedogs]

Sounds like you're over boosting, System shuts down till you lift foot and re plant it, need to NAD IT.
Have you plumbed all vacuum solenoid hoses correctly, search Chaz Yellowfoot {guru} you'll see where
you went wrong.

Go get it DYNOED

[BillsGU]

Just back off the boost a bit. You are over boosting and going into limp home mode. No problem and no danger of damage.

[june]

hi mate i suggest you look for a leak in the cooler piping, also have you fitted a dawes valve?

no apparent leaks, was told i didn'd need a dawes valve ?

[june]

bit hard when towing a 3 tonne van,but, will give it a go, thanks

[june]

not real sure what you mean, new to all this meachanical stuff, but, if you mean to do with the dawes valve, i do not have one

[Sir Roofy]

think you need to look into doing the N.A.D.S,IF YOUR OVER BOOSTING COULD BE OVER FUELING ,could go bang DO THE N.A.DS

[BillsGU]

not real sure what you mean, new to all this mechanical stuff, but, if you mean to do with the dawes valve, i do not have one

Sorry - thought you had a dawes valve. It would be easy to fix the problem then.

You can adjust the rod on the vacuum boost controller - but if it was me I would go to a mechanic to get it done the right way. Preferably on a dyno.

[krbrooking]

Sounds like it is over fueling ( the engine is starved of oxygen) check things like your air cleaner and so on or like the others said down boost, your chip might be adjustable. Also take it for a dive without the van on and give a good boot try and replicate the load on the motor without the weight and see if it still does it

[june]

sorry guys what does nads mean?

[MEGOMONSTER]

sorry guys what does nads mean?

Nissan Anti Detonation system
Catch can
Dawes and needle valve
And something else

Never argue with an idiot, cos he'll bring you down to his level, then beat you with experience. Y2K

[threedogs]

What boost do you have at 100k on a flat road and what EGT are you showing? When you NAD it you take the thinking away from the ECU and adjust it manually which you monitor via your boost and EGT guage, lots of black smoke ,overfuelling and may run hot. Should be easy enough to sort out as you have most mods. Mudski may have Dawes Valves in stock and Dependable distributors in SA will take your order over the phone $85 from memory for a needle valve

Re read your thread buy a DAWES valve and NEEDLE valve less than $150
Still don't know where you're from as someone close by may be able to help.

[june]

when towing 3 t van boost is 18 lb and pyro reads 540 degrees at 100 klms. no van on boost around 11 pyro reads 280 degrees. patrol is fitted for outback touring and is right on it limit of gross vehicle mass of 3 tonne.no apparent smoke. currently live Qld /Nsw border Pottsville.had egr blocked weeks ago by taipan exhaust problem has started since. they told me i did not need dawes valve as no problems exists to warrant one.vehicle has 100,000 klms on clock and owned since new serviced every 5000 klms. i believe i need a dawes as well. i can get one from taipan but they won't sell me one. thanks

[BillsGU]

Sometimes when the EGR is blocked the boost increases a small amount. If you were getting 18 psi you would be right at the upper limit. If you go any higher (it does vary a bit) the ECU sees this as a danger and sends the engine into "limp home mode". You will notice an instant loss of power. This is GOOD as it is designed to protect your engine. There are a couple of ways to wind back the boost so this does not happen - but the easiest, safest and best way to do it is to install the dawes valve. This will set the ABSOLUTE maximum boost to the engine at a level below the limp home level. It also means that it is IMPOSSIBLE for your boost to spike (as is the case with the ECU controlled boost). It is relatively easy for you to install the valve yourself (purchase the valve from a number of suppliers - see other threads for info) or if you are not sure get someone to do it for you (again search this forum for installers).