I need some help tuning my 12HT.
Background:
- 12HT purchased from overseas, purported to have very low miles, but who really knows
- Is in my 1981 FJ45 with H41
- injectors were rebuilt about 100 miles ago by a Central Plains Diesel in Kansas
- original turbo was leaking oil so I replaced it with a G Turbo G333
- 3in exhaust
- while injectors were out I did a compression test, 380 PSI on all cylinders, I'm at 6,300 ft, so correcting this for altitude puts this in the very healthy range
- turns over with the slightest bump of the key
- cooling system works great, aux temp gauge never goes over 180*
- I have EGT and boost gauges
- installed a G-turbo waste gate controller
- spill timed recently to OEM 11*
Issue:
I replaced the turbo at the same as I installed the new injectors. I didn't have EGT or boost gauges when it was running the factory turbo. When running the OEM setup (which I didn't do for very long, maybe 200 miles), I didn't have really any smoke, maybe a light haze.
With the Gturbo and rebuilt injectors, I'm getting more smoke than I want. I can hit 24psi in 3rd gear, but it takes a while to get there, and it's only for a brief second before I have to back off. It's not "black out the sun" smoke, but it's quite a bit heavier than I want. It doesn't seem to spool nearly as fast as it should. Gturbo's website says "with a proper tune can see 20psi as low as 1600 rpms." I'm not anywhere near that. I have the boost controller as tight as it will go. I will say, smoke aside, it has quite a bit of pep and will really scoot, so it's putting out a noticeable increase in power. Smoke doesn't really clear until 16psi or so, and then it reaches max boost so quickly, its only momentarily before I have to lift or shift.
Foot to the floor on a long grade and I've yet to get it over 1,000* F measured pre-turbo.
What I've tried so far- backing off the off boost fuel screw. I removed a factory safety wire, so that appears to have been untouched. The main fuel screw has a OEM cap on it, but it's pinched, which makes me think it might have been adjusted at some point. I've read that small increments on the off boost here make a big difference. I've backed it off 1/2 turn and can't notice any difference in smoke or spool. Before I keep screwing with it, I'd like some input from those in the know. It seems like the Gturbo should be able to handle all the fuel a stock pump and injectors can throw at it without smoking, but I'm clearly throwing a lot of unburnt fuel out the tailpipe.
Background:
- 12HT purchased from overseas, purported to have very low miles, but who really knows
- Is in my 1981 FJ45 with H41
- injectors were rebuilt about 100 miles ago by a Central Plains Diesel in Kansas
- original turbo was leaking oil so I replaced it with a G Turbo G333
- 3in exhaust
- while injectors were out I did a compression test, 380 PSI on all cylinders, I'm at 6,300 ft, so correcting this for altitude puts this in the very healthy range
- turns over with the slightest bump of the key
- cooling system works great, aux temp gauge never goes over 180*
- I have EGT and boost gauges
- installed a G-turbo waste gate controller
- spill timed recently to OEM 11*
Issue:
I replaced the turbo at the same as I installed the new injectors. I didn't have EGT or boost gauges when it was running the factory turbo. When running the OEM setup (which I didn't do for very long, maybe 200 miles), I didn't have really any smoke, maybe a light haze.
With the Gturbo and rebuilt injectors, I'm getting more smoke than I want. I can hit 24psi in 3rd gear, but it takes a while to get there, and it's only for a brief second before I have to back off. It's not "black out the sun" smoke, but it's quite a bit heavier than I want. It doesn't seem to spool nearly as fast as it should. Gturbo's website says "with a proper tune can see 20psi as low as 1600 rpms." I'm not anywhere near that. I have the boost controller as tight as it will go. I will say, smoke aside, it has quite a bit of pep and will really scoot, so it's putting out a noticeable increase in power. Smoke doesn't really clear until 16psi or so, and then it reaches max boost so quickly, its only momentarily before I have to lift or shift.
Foot to the floor on a long grade and I've yet to get it over 1,000* F measured pre-turbo.
What I've tried so far- backing off the off boost fuel screw. I removed a factory safety wire, so that appears to have been untouched. The main fuel screw has a OEM cap on it, but it's pinched, which makes me think it might have been adjusted at some point. I've read that small increments on the off boost here make a big difference. I've backed it off 1/2 turn and can't notice any difference in smoke or spool. Before I keep screwing with it, I'd like some input from those in the know. It seems like the Gturbo should be able to handle all the fuel a stock pump and injectors can throw at it without smoking, but I'm clearly throwing a lot of unburnt fuel out the tailpipe.
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