TDI 1st Gen Tacoma Swap

[jmodge]

Vane levers wear into the ring. If there’s significant play at that point you most likely will never get it to act correctly.

 

[jmodge]

But without seeing what you’re dealing with it’s just a guessing game.
Have you disconnected the rod from the vane actuating lever? The lever should cycle with zero resistance. Somehow the vanes are partially closed if you’re getting boost when the ecu isn’t calling for any, such as when in limp mode

 

[jimbote]

As I was adjusting it this time I was reminded that the rod isn't long enough. Even when the adjuster is just off the threads of the rod there is still a little bit of play in the vane lever. I'm sure I bought some random diaphragm for the lowest price and it just doesn't fit well.

Thete are some turbos that use shorter actuators at the threads and even some with a shorter adjuster heim. Maybe you ended up with one of those?

 

[BimmerTim]

But without seeing what you’re dealing with it’s just a guessing game.
Have you disconnected the rod from the vane actuating lever? The lever should cycle with zero resistance. Somehow the vanes are partially closed if you’re getting boost when the ecu isn’t calling for any, such as when in limp mode

I've had the rod and lever apart a few times and it always feels like the lever moves freely. I think I need to actually set set the down position via vacuum. This time I didn't, but last time I did. I'll do that this week and report back. When I first got everything back together after the IP, injectors, and head refresh with the tune it didn't seem like it was going into limp mode. Then it did once, and then all of the time. Now, post "adjustment" it only does it on the highway.

Thete are some turbos that use shorter actuators at the threads and even some with a shorter adjuster heim. Maybe you ended up with one of those?

Could be. I didn't know there were long/short combos. It would make sense that this engine would be the oddball, since it's from an early 99 mk4.

I took a couple of videos to show what I'm seeing now for symptoms.

This video is showing that at higher RPMs, around 3k, if I let off throttle I'm still making around 10psi. That drops off as RPMs drop, but it seems odd that I would be making that much boost off throttle.

This video is showing a 2nd gear throttle stab and boost spike over 30psi.

For a bit more background. When I do go into limp mode off-throttle boost is 0, and max on throttle boost is 10psi, but only up around 3k. Mostly stays between 5 and 10psi in the 1500-2500 rpm range.

 

[jmodge]

If the rod is set to max length and you’re still getting boost try this. Pull the vacuum line so the diaphragm is at rest. Remove the snap ring to see if the vanes are fully open and the diaphragm is not restricting movement. This I’m asking assuming that with vacuum applied the lever hits the stop screw.

Has the cartridge ever been removed? It seems to me I had installed a vane ring flipped on the wrong side once and it limited range.

 

[BimmerTim]

If the rod is set to max length and you’re still getting boost try this. Pull the vacuum line so the diaphragm is at rest. Remove the snap ring to see if the vanes are fully open and the diaphragm is not restricting movement. This I’m asking assuming that with vacuum applied the lever hits the stop screw.

Has the cartridge ever been removed? It seems to me I had installed a vane ring flipped on the wrong side once and it limited range.

I can't get the rod end off of the actuator arm with the diaphragm installed. When I "fixed" it this last time I just went by memory of where it was installed. I need to verify that the actuator is hitting the stop at 18"Hg. I doubt it, honestly.

To my knowledge, no, but the engine has all of the miles. I have not pulled the cartridge, I have only pulled the compressor housing to clean and clock it.

 

[BimmerTim]

Checked the rod adjustment with MityVac and gauge today. The rod is 100% too short. I checked that the vane actuator arm moves 100% freely from hard stop to hard stop.

When I apply 18 inHg to the diaphragm the threaded rod doesn't reach the adjuster portion even when the lever arm is on the stop.

I think what I did last time was just put minimal threads into the adjuster to get it as close as I could. Now I obviously need to do something about it, since it's causing issues.

 

[jimbote]

Checked the rod adjustment with MityVac and gauge today. The rod is 100% too short. I checked that the vane actuator arm moves 100% freely from hard stop to hard stop.

When I apply 18 inHg to the diaphragm the threaded rod doesn't reach the adjuster portion even when the lever arm is on the stop.

I think what I did last time was just put minimal threads into the adjuster to get it as close as I could. Now I obviously need to do something about it, since it's causing issues.

Can you measure the extended threaded rod (no vacuum) and the heim adjuster? I'll compare to what i have here.

 

[BimmerTim]

Can you measure the extended threaded rod (no vacuum) and the heim adjuster? I'll compare to what i have here.

I finally got out there to take a look at this. With the vacuum actuator off, from the bracket to the tip of the threads is 1-7/8".

My fix was to cut the threads back so they are about 3/4" long, thread a nut all the way down, then put a 1" long coupling nut with a bunch of red locktite all the way down to the first nut and lock them together. Then I took an M6 stainless threaded stud and red locktite that into the other side of the coupling nut, then another nut to lock the stud into the coupling nut. Finally, I cut the stainless stud so that threaded rod tip to vacuum actuator was 2-3/8" long.

I reinstalled and was able to get the actuator arm to touch the stop at 18inHg.

It is no longer going into limp mode for over boost. I still need to log the requested v actual, but I drove it for about hour and it was fine. So, I drove it home and it was totally fine. Obviously, much slower than overboosting to the moon. Haha. I can also get haze out of the exhaust, which I was never able to before.

It was also edging 100 degF yesterday and the A/C was blowing out of the center vent at 47 degF. I love it.

I popped a Scangage in to just monitor a few things. I found that once warm the coolant temps stays between 195-207 degF. Maybe a little higher than I would like on the high end, but not crazy. My favorite finding was that my IATs were only about 5-10 degF above ambient, so I'm SUPER happy with the intercooler performance.

The only annoyance from yesterday was stalling the truck a couple of times, because the A/C adds enough load at idle that it just behaves differently than I'm expecting. If I turn it off it drives normally.

Since putting the truck back together it's basically only idled or been beat the pants off of trying to sort out the little issues I was having. I filled up yesterday and still found it got 26.5 mpg. Now that everything SHOULD be good, or better, we'll see if we can get it over 30.

 

[jimbote]

Very good. Yeah, occasionally, I stall mine with AC on.

 

[BimmerTim]

Yeah, I figure I'll just have remember and/or stall it once in a while. Not too big of a deal.

I just drove it around a bunch to Home Depot and Menards around town and I also noticed that once I've been driving for a bit the boost is more likely to spike boost up to and just over 20-22psi. For the first bit of driving it won't even spike to 20, only 18-ish psi. Maybe this is not an actual issue, but for me the extra boost slips the clutch. Which I do have a Supra clutch to install, so maybe even then it's only an issue temporarily.

Otherwise, I think I might see if @burpod has any suggestions for IQ/timing that I can adjust to smooth out the tune. It seems a little lacking on low end and I think the idle could be smoother.

But, all in all I'm pretty hyped on this thing and driving it is great.

 

[BimmerTim]

Drove it a bunch today. Down the highway 30 minutes and back. Around town to run some errands. No limp mode. Plenty of power all over compared to the OG Tacoma engine.

I love this truck.

 

[jmodge]

Good to hear you got your actuator issues sorted out, congratulations.

 

[BimmerTim]

I finally installed the long probe and hooked up all of the VDO gauges in the truck today. It's so much easier to wrap my head around the sweeping EGT gauge compared to the numbers. Obviously, with the probe in the exhaust flow the readings are higher and faster now, which is nice.

When running at around 70-80 mph in 5th at 23-2500 rpm, if I hold the throttle steady it'll sit at about 1200 degF. Going up a grade it'll sit at about 1450 degF. If I really lay into it I can get it to about 1500-1550 degF, but not really any higher. Similar story with the A/C on, but on average the temps are slightly higher.

I also realized that I never really showed the latest gauge panel setup in detail, so here are some pictures.

I'm going to live with these gauges and setup for a while to see if I like the layout and not having a real radio. If the Bluetooth only is tolerable I'll probably change the gauges to a different style. Mostly because I'd like to have a more useful third gauge than outside temp. I just don't want a mechanical oil pressure gauge and they don't have an oil temp gauge in this style.

But, so far so good.

Next things are just more wrapping up of little bits. Specifically, I still need to wire up my glow plugs, though I haven't really needed them to this point. Once those are wired in the CEL should be gone. I also still have to figure out how to integrate the Tacoma cruise stalk in. It works very differently than the VW one, so I'll probably have to brush up on my coding and fiddle with an Arduino.

The exhaust is not finished completely either. It's currently just dumping down after the muffler, which is directly under the passenger seat, and it drones like a mofo. The muffler I have installed is a Vibrant Streetpower. I've really liked those in all of my car applications, but I think it might be too loud for my truck taste. Thinking about either changing to or adding a Vibrant Ultra Quiet resonator to see if I can get it quieted up some. I also have a high flow diesel cat to install. The intent there is to lessen the diesel smell at idle or when you're standing around it running.

Any other changes or upgrades are out a bit and not set in stone.

 

[jimbote]

I ran my exhaust like yours for the first few months. It was droney, but when i exited out the bed side it got much better. No muffler either.

 

[BimmerTim]

I ran my exhaust like yours for the first few months. It was droney, but when i exited out the bed side it got much better. No muffler either.

Is it still loud-ish? I suppose I could just start with running it all the out from under truck to see.

 

[jimbote]

Is it still loud-ish? I suppose I could just start with running it all the out from under truck to see.

Not loud enough to be annoying, but I've had over 14 years to get used to it

 

[PickleRick]

Another vote for 2.5 inch back exhaust with no cat/resonator/muffler. A turbo is a muffler!

 

[BimmerTim]

Another vote for 2.5 inch back exhaust with no cat/resonator/muffler. A turbo is a muffler!

Ha! I had that on my old mk4 tdi. Too loud for my old ears these days.

I just ordered a bunch of 2.5in stainless straights, bends, and v-bands. I'll get it out from under that truck and see what's what.

 

[jmodge]

Mine’s 3” all the way back with a muffler. I would have to look at what was done with the downpipe to flange, pretty mellow though.
Gauges are on the windshield post. I don’t know if those pillar pods are still available, but I imagine you have the skills and resources to make your own if you so desire. I like them there rather than glancing down.

 

[PickleRick]

I hear the drone of my mud terrains over that of the exhaust unless I'm romping on it, even with the top off. Not they the KTT soft top really does anything for sound dampening.

I can't imagine my life without v band clamps. Having the exhaust and/or down pipe removable in second is what all OEM car manufacturers should go to.

 

[burpod]

those are some crazy high EGTs for just cruising!! o.0 granted for a truck but still... thats way too much

 

[jmodge]

I hear the drone of my mud terrains over that of the exhaust unless I'm romping on it, even with the top off. Not they the KTT soft top really does anything for sound dampening.

I can't imagine my life without v band clamps. Having the exhaust and/or down pipe removable in second is what all OEM car manufacturers should go to.

LOL, probably why I think my exhaust is mellow.

 

[BimmerTim]

those are some crazy high EGTs for just cruising!! o.0 granted for a truck but still... thats way too much

Keep in mind it's not only a truck, it's also got really long gearing, it's lifted, and it's on 33" tires.

The IQ was set to max, which yielded about 6.0-ish mg/str. I put the adjustment value back to 32768, which brought the IQ to about 3.8-ish. EGTs seem to be about the same, maybe a little higher if I push it hard.

I would gladly do some logs to get your thoughts on the setup. The ECU is socketed now, so if there is anything tune-wise that would be better, I'm open to that as well.

When I was talking with Kerma about the original tune, I told them I wanted low smoke and low EGTs. I'm not looking for max power by any means.

 

[PickleRick]

Do you have a smaller set of tires you can try?

When I'm at 70-75 I'm between 2800 and 3000 rpms. EGT will climb to maybe 1000-1100 going up hills maintaining those speeds.

It's usually closer to 800 on flat ground.

It will rise a little higher doing those same roads at 60 which is about 2300 rpms.

I think I've mentioned this before but on my 285/70/17 tires running 4.10 gears the performance on back roads at 40-45 mph was dreadful as I was at about 2000 rpms and constantly had to either lug the motor or downshift up hills or dealing with Sunday driver types

In city daily commuting the traffic light to traffic light acceleration suckes.

Going to 4.30 gears made it peppy and much more fun at all speeds. I'm not taking a lifted 1st Gen 4 runner to 80-90 mph, it's a death wish. 70-75 is my personal max.

 

[PradoTDI]

That does seem pretty hot. I’m running 31.5” tires, 4.88 diffs, and a 0.69:1 5th gear which puts me at around 2500 rpm @ 70 mph. My vehicle weighs 4700-5000lbs under normal conditions, has the aerodynamics of a brick and usually has an RTT on top.

Engine modifications are 0.216 injectors, a BHW turbo, and until this spring a Malone stage 4, now running a Burpod tune. EGT at 70 on flat ground was always 1000-1100°F with the Malone tune, now it is 900-1000°F. Pulling hills or accelerating would put it in the 1300°F+ pretty quickly, I once saw 1650°F on a full throttle 3rd gear pull. With the Burpod tune it can still get over 1300, but takes a lot longer to get there.

 

[BimmerTim]

Do you have a smaller set of tires you can try?

When I'm at 70-75 I'm between 2800 and 3000 rpms. EGT will climb to maybe 1000-1100 going up hills maintaining those speeds.

It's usually closer to 800 on flat ground.

It will rise a little higher doing those same roads at 60 which is about 2300 rpms.

I think I've mentioned this before but on my 285/70/17 tires running 4.10 gears the performance on back roads at 40-45 mph was dreadful as I was at about 2000 rpms and constantly had to either lug the motor or downshift up hills or dealing with Sunday driver types

In city daily commuting the traffic light to traffic light acceleration suckes.

Going to 4.30 gears made it peppy and much more fun at all speeds. I'm not taking a lifted 1st Gen 4 runner to 80-90 mph, it's a death wish. 70-75 is my personal max.

That does seem pretty hot. I’m running 31.5” tires, 4.88 diffs, and a 0.69:1 5th gear which puts me at around 2500 rpm @ 70 mph. My vehicle weighs 4700-5000lbs under normal conditions, has the aerodynamics of a brick and usually has an RTT on top.

Engine modifications are 0.216 injectors, a BHW turbo, and until this spring a Malone stage 4, now running a Burpod tune. EGT at 70 on flat ground was always 1000-1100°F with the Malone tune, now it is 900-1000°F. Pulling hills or accelerating would put it in the 1300°F+ pretty quickly, I once saw 1650°F on a full throttle 3rd gear pull. With the Burpod tune it can still get over 1300, but takes a lot longer to get there.

Yeah, I think this all makes sense. I'm on 33in tires, with 3.56 gears, and 0.81 final drive. At 70mph in 5th I'm basically sitting at 2000 rpm. If I drop down into 4th the temps drop too. Maybe loading up the engine that much at 2000rpm is just rocketing the EGT up.

I have 2 sets of 31in tires, but they are 15s and I can only run 16s with the Tundra brakes. TLR, no.

I don't typically do much more than 70-75mph. I was hoping to be able to chug along the interstate at 80 through the plains and parts of the West, but if that's just not in the cards for the truck/engine combo, I don't really have a problem with gearing to only do 70mph.

 

[PradoTDI]

Yeah, I think this all makes sense. I'm on 33in tires, with 3.56 gears, and 0.81 final drive. At 70mph in 5th I'm basically sitting at 2000 rpm. If I drop down into 4th the temps drop too. Maybe loading up the engine that much at 2000rpm is just rocketing the EGT up.

I have 2 sets of 31in tires, but they are 15s and I can only run 16s with the Tundra brakes. TLR, no.

I don't typically do much more than 70-75mph. I was hoping to be able to chug along the interstate at 80 through the plains and parts of the West, but if that's just not in the cards for the truck/engine combo, I don't really have a problem with gearing to only do 70mph.

Yeah, 2000@70 is probably too high of gearing. My 5th ratio seems a little bit tall for my setup, but it does ok. I usually have to downshift to 4th and run at 55 when pulling large grades. That said, cruising speed on flat ground is usually 77mph, I don’t like going much faster than that. Once hit 84, seemed really fast for the chassis and suspension.

A stock Jetta runs nearly 3k rpm at 80 and is happy to do that all day, it doesn’t seem to have an adverse effect on fuel economy. I don’t see much difference in fuel economy between 70 and 77 mph.

 

[BimmerTim]

Yeah, 2000@70 is probably too high of gearing. My 5th ratio seems a little bit tall for my setup, but it does ok. I usually have to downshift to 4th and run at 55 when pulling large grades. That said, cruising speed on flat ground is usually 77mph, I don’t like going much faster than that. Once hit 84, seemed really fast for the chassis and suspension.

A stock Jetta runs nearly 3k rpm at 80 and is happy to do that all day, it doesn’t seem to have an adverse effect on fuel economy. I don’t see much difference in fuel economy between 70 and 77 mph.

4th @70mph is roughly in the 2600rpm realm. I'll have to verify that again.

I do want to drop back to a 31in tire. I want to use up all of the current Toyos, so maybe I'll just run 4th on the highway for now.

 

[jimbote]

Keep in mind it's not only a truck, it's also got really long gearing, it's lifted, and it's on 33" tires.

The IQ was set to max, which yielded about 6.0-ish mg/str. I put the adjustment value back to 32768, which brought the IQ to about 3.8-ish. EGTs seem to be about the same, maybe a little higher if I push it hard.

I would gladly do some logs to get your thoughts on the setup. The ECU is socketed now, so if there is anything tune-wise that would be better, I'm open to that as well.

When I was talking with Kerma about the original tune, I told them I wanted low smoke and low EGTs. I'm not looking for max power by any means.

I have to agree with Burpod. My setup is similar. 265 70 17. Lifted, 4.10s. Cruises highway speed around 8-850. Rarely hits 1100-1200, and thats under sustained full chooch. Stewart Warner gauge with probe mounted in the BHW egt port. Truck is not slow, does not struggle on hills. 31-33 mpg.