TruckA's 1984 720 4x4 gasser conversion to SD22

#31

Could be the IPC linkage bushings are worn out -- nylon busihings on the rod between the IPC motor's arm and the IP. The IPC's arm rotates to the STOP position but doesn't quite pull it far enough. Symptom is often that the engine will slow down but not quite stop.

Or, maybe the IPC isn't moving the IP's arm at all. The arm is detented to the RUN position so you can drive it with no IPC connected at all, in many climates.

Philip can provide a link to more info, but there's a topic that covers the DPC/IPC stuff.

#32

The nylon bushings looked okay, so I'll have to keep digging into why it didn't want to stop. The fuse has blown twice for the glow plug system, it blew the first time when I took the truck out on the first drive, and the second time when I tried to start it up cold a few days later. So there's a short or another issue going on somewhere.

What a difference having a clean glow plug harness makes. I was still having trouble getting the engine to fire when cold, it was sounding like only one cylinder was firing. After testing the voltages at each glow plug, only the rear plug was getting voltage. After sanding the crimped terminals and scrubbing the glow plug contacts, it fires up like a champ!

I also found a craigslist special on some alloy wheels for the truck this week, so they're now on the truck. Even though they are Toyota wheels, I'm not bothered, I'll paint the center caps black so the logo will be less noticeable. I had messed up trying to paint the stock chrome wheels that were badly rusted, and I didn't want to repaint them again, so I was glad to find a whole set of wheels and tires for $50.

It looks like I may be able to get tags for this truck next week and start getting out on the road. That also means that I need to get my turbo Mighty Max ready to be sold which is a little sad, but I will like the cash.

#33

Latest bought used turbo is finally installed. Its a TD05 from an early 90's Mitsubishi Eclipse. I know the pipe from the turbo to the throttle is sloppy, but its a temporary setup that I'll replace once all the bugs are worked out. This time, instead of a rubber hose bursting again, I bought 3/8 steel line and brass fittings from Lowes and used my flaring tool to make some good oil feed and drain lines. I made a series line where the oil feeds from the block to the turbo, and then there's a hard line underneath that connects to the vacuum pump mounted on the back of the alternator. I also tapped into the coolant hard lines near the thermostat to feed the turbo, it was nice to find that the fittings are a standard 3/8" pipe size. The downpipe is made of 2" steel pipe and two large 90 degree elbows to make the U-turn back up to the turbo. I used a 1/2" turbo flanges bought from roadraceengineering.com for the exhaust inlet and outlets. I started the truck last night and didn't see any leaks, and I'm waiting on the battery to finish charging and I'll try it on the road. The turbo did spool and I saw 2-3 pounds of boost from revving the engine. Hopefully it will work out this time for good.

David

#34

Thanks for the update, and I esp. appreciate the pictures.

One point of clarification: though 3/8 NPT will fit the thermostat housing, the OEM thread isn't NPT. See this post for details.

Love the galv water ells welded back-to-back! Great lash-up

Looking forward to more reports.

#35

The welder did the chore on the elbows, I had it set on the highest setting and it penetrated well. I decided the turbo gods hate me, this turbo has a shot oil seal as well as did the turbo before it. I don't see how I'm damaging them when I install them. I've been using the same turbine housing so I don't have to remove the whole turbo, only the compressor side of the turbo with the internals attached. I'm not going to roll the dice on another used turbo and rebuilt turbos are $500+, so I'll try a rebuild kit on this latest turbo. Still frustratingly boostless at the present time.

#36

TruckA wrote:The welder did the chore on the elbows, I had it set on the highest setting and it penetrated well. I decided the turbo gods hate me, .... Still frustratingly boostless at the present time.

I'm speechless. If you were only 1/2" tall and started walking from the air filter .. through the engine combusion ... through the exhaust system ... you'd be crying by the time you reached the turbo. Experienced engineers make exhaust / turbo systems look easy.

#37

TruckA wrote:... I decided the turbo gods hate me, this turbo has a shot oil seal as well as did the turbo before it....(

Your lucks down, dont play the lottery

I used the galv pipe for a exhaust on a chrysler slant six that is my hobby motor, to rig up twin donaldson mufflers with a rain cap, I welded it sucessfully at something around 120 amps except I didnt lay a bead all the way around, I just threaded them tight and laid a small bead to keep it from loosening, just avoid breathing the gasses that come off of it, its vaporized zinc, that probably solidifies in your lungs.

#38

Thanks for the heads up about the zinc, if I ever have to do it again, I'll wear a breathing mask as well. A keen member on another board told me about a custom oil line he made once for his GSX from some extra -6AN line (3/8") he had laying around and he experienced the same problem I'm having, oil blowing out into the exhaust. He found that this turbo needs at least a -10AN or 5/8" line to drain properly, and in my case it probably doesn't help that the oil drain line feeds the vacuum pump that has a very small inlet. So, I'll rebuild the turbo and make two separate feed and drain lines for the pump and turbo. I remember reading a post that I think was by Al about a block fitting that may be able to be used for a second drain line. I think I know which bolt it is on the block, but if someone could help me find that thread, I would appreciate it, I've been searching for it for a while this morning.

...

Found what I was looking for:

From this topic:
http://nissandiesel.dyndns.org/viewtopi ... g&start=30

#39

The TD05H has piston ring type seals which are pretty tough. In addition, you have the throttle body after the turbo so it really doesn't see any vacuum to pull oil into the compressor. Remove the air inlet hose on the front and you can pinch the end of the shaft with your fingers. You should not be able to feel any up and down clearance and only a little thrust clearance. Excessive thrust clearance won't cause oil problems, but will allow the impeller to hit the housing. If the shaft moves up and down it needs to be rebuilt, which is cheap for a Mitsubishi if it is only bearings and seals. Mine costs $100 to freshen up, which I've done 3 times in the last 13 years.

The problem with the other block port is that it is partially covered by the motor mount.

I also teed into the vacuum pump drain line, but I enlarged the hole so that I could use 5/8" line instead of 1/2". Making and using a separate port is probably a better solution but mine has been working ok.

Run a line off the exhaust right in front of the turbo so that you can see exhaust pressure along side your intake manifold pressure. The two pressures should be nearly balanced, but the throttle body will mess that up some. Also, be aware that if you run your boost pressure gauge off the intake plenum as you have, it may not be the same as a manifold reading because of the throttle body. That is why Bacho was reading 2-3 lbs boost at idle on his setup.

Be absolutely certain that you have no exhaust leaks because that will really drop the turbo performance, especially with a larger turbo like you are using. Also be sure that the wastegate is tied shut and that there is no leakage past it. I welded mine shut from the inside.

I am really interested in seeing how the TD05 works on the SD22. The gas motor that it came off (2.0) flows a third more air than the SD22, and makes more exhaust heat, so theoretically it is too big, but as I have said before, very little about turbocharging is intuitive, and much of it is counter intuitive.

#40

Knucklehead wrote:Be absolutely certain that you have no exhaust leaks because that will really drop the turbo performance . . .

Ditto on that.

#41

avoid breathing the gasses that come off of it, its vaporized zinc, that probably solidifies in your lungs.

TruckA wrote:Thanks for the heads up about the zinc, if I ever have to do it again, I'll wear a breathing mask as well.

A good practice to avoid the risk of zinc vapor is to soak the galvanized parts in muriatic acid. This will remove the zinc and make for a better weld. Obviously perform this task outdoors.

#42

I felt boost on the diesel for the first time last night. I've rebuilt the turbo, installed a 5/8" oil drain line into the pan, and reworked the oil feed line. There's a few oil leaks I need to plug up and I need to hook the turbo coolant lines back up. It seems to like the 14b and it moves a lot better which makes me happy. Finally it works, more to come.

#43

Knucklehead wrote:-snip-
I also teed into the vacuum pump drain line, but I enlarged the hole so that I could use 5/8" line instead of 1/2". Making and using a separate port is probably a better solution but mine has been working ok.-snip-.

#44

Too late to go that route, mine is coming into the rear left top side of the 4x4 oil pan and I have the brake booster vacuum pump drain line going into its stock location. I just drove the truck in to work from my lunch break and its seeing 3-5psi steady with 7psi if you keep on the throttle. I haven't had a chance to test it on the highway yet, but the EGT numbers look fine so far. Its definitely a little faster, nothing to take it to the drag strip for, but its nice to keep my speed steady and actually accelerate a little when going up hills.

#45

Update,

The truck is now pushing 11-12 psi max and is running well after some more tuning. I'll now have to watch the gas mileage to see how that has changed. Uncle Sam was nice to me this year so I'm shopping for tires, anyone have recommendations for a good value AT or MT tires? I had been looking at BFGoodrich MT's as they last 35-45,000 from what I've read, Hankook DynaPro MT's sound okay but only last 30,000 from other's experience, and I've looked at Kumho Road Venture MT's with similar results as the Hankooks. I'm not sure on what size I want to run just yet, or what largest size will fit without a lift, but I'd like to have a little better off-road capability than the worn AT's installed now, with decent road ride/mileage and wet stoppage.

David

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