2lt feels like it's bogging down (1 Viewer)

[4Ruster]

Hey all. Here for another question yet again. 1986 4runner, 1985 early rocker 2lt. So I just had my injection pump serviced and calibrated back to factory specification. Fantastic job done. It runs so much better but I'm still noticing down low (under 2500 RPM) when driving and I get to a hill and load it up a bit, it builds a bit more boost (typically will cruise flat around 1-2 PSI), around 3-4 PSI and I hear the turbo spoiling up but it doesn't really accelerate, so I give it more throttle, and it builds maybe up to 6 psi of boost but barely accelerates faster.

I have to give it quite a bit more throttle to get to actually accelerate up the hill to hold speed and I don't know how I feel about running 9+ PSI everywhere. It has a used Subaru TD04L turbo on it. It burns oil but the impeller spins fine.

The gearing in my 4runner is 4.56, so going down the highway I really only go 80 km/h at 2500RPM already in 5th gear, but any hill I get to, I need to downshift to 4th just to hold speed otherwise it feels and sounds like it's bogging down, boost and EGTs will go up, but it still slows down a bit.

Is this just normal or am I looking at a turbo/mechanical issue?

 

[AirheadNut]

Your boost levels are much lower than I would expect, and too low to make any appreciable power. 6 psi on a diesel is peanuts, my 2L-TE powered LJ78 would regularly run 10-12psi when at cruising speed, and would pull steady 14psi on acceleration or when climbing hills.

What EGT numbers are you seeing when you are trying to pull hills? Thinking either your fuel isn't turned up enough to make proper boost, your waste gate is out of adjustment, or you have a boost leak somewhere.

 

[4Ruster]

Huh. Well here's a video driving around. I can get 14 psi but I have to floor it and only above 3000 RPM

Wastegate doesn't start opening until 12 ish PSI and is fully open at 19.

EGTs are around 500-900 driving around.

 

[AirheadNut]

Definitely making boost way later than it should, you ought to see reasonable boost levels by 2000 rpm and be able to hold boost under partial throttle. If EGT's are peaking at 900ºF under normal conditions then your tune is probably too lean and could do with more fuel. Based on your video I would expect the engine to feel almost naturally aspirated under normal driving conditions; no wonder it feels slow!

You said the turbo is leaking oil, it occurred to me that if the turbine shaft bearings were worn it could take significantly higher than normal exhaust pressure and flow to create boost. Have you checked play in the turbine shaft recently?

 

[Dougal]

What's the full spec on the turbo? You might have a turbine housing that's too big and/or exhaust leaks.

 

[4Ruster]

TD04L-13T

I took it up a hill and it was only holding 5 PSI unless I floored it, and I'm not flooring a 2lt

 

[4Ruster]

Have you checked play in the turbine shaft recently

There's a bit of side to side but no in and out play

 

[AussieHJCruza]

TD04L-13T

I took it up a hill and it was only holding 5 PSI unless I floored it, and I'm not flooring a 2lt

Why not floor it? If your tune prohibits flooring it due to EGT or ECT, it needs to be sorted.

We have no idea what max boost and EGT are if you won't run at WOT under load.

 

[bj70bc]

yes, wot is the way to check the tune, thats the info you need to know

 

[AirheadNut]

Even so that engine should build significantly more boost than that on medium throttle. I know nothing about turbo specs and sizing (that's @Dougal's wheelhouse) but given that is correct I still think you've either got a boost leak, a bad turbo or too lean of a tune.

 

[bj70bc]

Even so that engine should build significantly more boost than that on medium throttle. I know nothing about turbo specs and sizing (that's @Dougal's wheelhouse) but given that is correct I still think you've either got a boost leak, a bad turbo or too lean of a tune.

yuup
airheadnut for the win