20psi boost is that to high?

gooday to all..my08 CRTD IS BOOSTING 2Opsi under load is that to much for this engine..i know the question is a little vague but if u can help me out with an answer would be appreciated or if u need more info. let me know. cheers xcape08

Gday mate,

have you fitted a Dawes valve? have you set the boost to 20?

Seems too high? have you got a Pyro gauge? what are you temps like? why have you boosted it up so high? Has it ever been dyno'd? is the fuel set up to suit the 20psi?

not really mate they can see figures anywhere from 16-22psi the CRD's seem to hae all the issues solved now

when i first bought the Patrol new, i had problems with burning a lot of fuel,a lot of black smoke rear end,had it dyno'd fuel ratio was way out,only way to try and solve it was by having more boost and air flow,ratio of fuel to air did decrease but still,blowing some smoke under load.i do have a EGT gauge and temps. under load are reaching about 500-550 C.normal driving around 200-400 C.when the Patrol was only 14months old i had to have the exhaust manifold done due to warping(heat to much fuel).Nissan Australia didnt want to know anything about it.just recently i had to have the EGR valve replaced,couldnt be repaired again, cause heat or to much fuel. Last week i found out the exhaust manifold has warped again and the turbo has a slight oil leak.I have sent al this info to Nissan Australia through a Nissan dealership and im waiting for a reply tomorrow,even though its out of warranty,the do provide a good will warranty,fingers crossed they will come to the party,the are aware of the cars history.So the reason why its at 20 psi..was to try and level out the fuel/air ratio,but im concerned wether this is causing other problems. the patrol does have gas as well(.injected).
thanks for answering my thread but if uve got anymore info ill be much appreciated ur thoughts.

hi MudRunner thanks for ur reply,i did reply with more answer to ur questions,if u can give me some more feedback that would be great

Hmmmm... Mate i am certainly no expert on the CRD 3.0 engine but what you have written about your car would indicate that there is a fault i would have though that Nissan Australia should Own. If your Dyno Tuner had to bump up the Boost to 20 to even out the fuel /air ration from a factory setup surely that cant be right and surely that cant be your fault?? If anything Nissan Australia should have been looking early at why that was needed?

Push them hard mate. Has it been doing that only since the Gas went on? that will be their out i reckon?

Anyone else with any ideas?

hi MudRunner...no the patrol was blowing black smoke when it was stock standard.i was getting egt temps under load and towing of nearly 700-800C..when the car was only 18months old i had to have the exhaust manifold done under warranty because it warped. i used to complain all the time to the Dealer didnt want to know about it.they kept saying it was in Nissans tolerance...blah..blah blah..so thats when i had to look at other alternatives to get the ratio right. the gas injection has never been an issue, i dont run it most of the time.

While CrD ZD30 can run at higher boost than previous Di and for sure can run hotter EGTs (up to 700°) something is amiss if a tuner needs to compensate with increased boost for what appears to be too much fuel being injected. (black smoke) How's fuel consumption?
Also I'd like to know how did the tuner raise boost to 20 psi. As far as I know engine ECU is fully in control of boost, it also uses EGR to control it as well. So e.g. if one blocks egr than boost levels are much higher.
Few things spring to mind, is VNT turbo working correctly and just in case that trim codes for injectors stored in the engine ECU are correct?
Cheers

hi Rumcajs...the tuner got by the ECU by bypassing the airflow meter..electronically, it tricks the ECU,so it allows more are flow,he also put in a VNT valve to get the higher boost.The code injectors is what if been trying to find out from Nissan,if its correct and set right...but again it falls on deaf ears,they keep saying its within the limits.Fuel comp. isnt great but its better than what it used to be. The EGR isnt blocked, but i did have to replace it with a new one only 2 weeks ago because it was shot,full of soot and the trap door was shut closed,Nissan couldnt tell me what could of caused it.
it is a problem ive been trying to solve for a long time, but cant seem to get the right answer.
anymore suggestion please pass them on. Cheers

Injector trim codes are stamped on the housing/body of the injector and the codes are entered as parameters in the ECU for each and must be correct for every cylinder. So either take it to Bosch fuel injection service joint and ask them if they're able to confirm the settings for each injector or take it to those idiots from Nissan to do this simple check and insist they do it in front of you.
I'm afraid the changes your tuner had done will now make it much harder to track down the real cause of what seems like over fueling.
Remember upping the boost and airflow values causes more fuel to be injected so if fuel metering is incorrect/suspect for example (let say that injector/s are leaking/ trim codes are incorrect) black smoke is evident.
Cheers

Edit: I was thinking about this a bit more I'm wondering what is the rest of the exhaust like if the exhaust manifold is warping from the heat. I'd be checking if the cat is also not partially blocked from all that exhaust soot. Also Nissan had some issues with some CrD model had no trim codes entered in the engine ECU.