12HT tuning help

[TheBussman]

Have a boost controller and it’s maxed out. No boost leaks the last time I checked, though it bleeds off pressure fairly quick. I’m referencing boost from a tap in the crossover tube and can see 24psi on a long hill, maybe more but I back off at that point. I have a full 3in exhaust. I’ve contacted gturbo but they just tell me to “get a dyno tune”. I am at 6,500 ft of altitude. Compression test was great. Exhaust temps never go over 1,000F pre turbo.

It seems to me like it pulls really hard and spool is pretty quick, but just smokier than it should be. I wonder if the injector rebuild wasn’t quite right, they didn’t provide a balance sheet or anything. I’ve been tempted to have my spare set rebuilt from a more experienced shop with Toyota diesel familiarity.

pretty normal to bleed off the pressure quick as you have some intake valves open as long as you don't hear anything leaking or see any bubbles using soap. have you tried turning down the boost controller? I dont really know how big that turbo is, but adjusted lower is less backpressure and that could help reduce the smoke, with EGTs that low it certainly seems you dont need more boost. With inline pumps having the cyls out of balance will certainly make more smoke but any injection pump shop should know how important that is toyota/denso familer or not. it's the same idea on a bosch pump. one time i had injectors rebuilt and one of them was 500PSI lower then the rest.... its possible, they did use denso nozzles?

 

[Kmehr]

pretty normal to bleed off the pressure quick as you have some intake valves open as long as you don't hear anything leaking or see any bubbles using soap. have you tried turning down the boost controller? I dont really know how big that turbo is, but adjusted lower is less backpressure and that could help reduce the smoke, with EGTs that low it certainly seems you dont need more boost. With inline pumps having the cyls out of balance will certainly make more smoke but any injection pump shop should know how important that is toyota/denso familer or not. it's the same idea on a bosch pump. one time i had injectors rebuilt and one of them was 500PSI lower then the rest.... its possible, they did use denso nozzles?

No bubbles with soap and water on the intake track, so feeling good there. Interesting idea on boost controller, might giv e that a try. The shop told me they used denso nozzles, and I sent them the spec sheet from the manual, but who knows without testing them.