New Delica Owner - Low power, leaky turbo, running cold

[team_ream]

Hi Everyone,
I am a recent Delica convert, though I still have a few Toyota Vans and am worried I might need to switch back!

I just picked up a gorgeous '91 Super Exceed that has allegedly had a major overhaul, including head gasket in the past few years and everything inside and out looks nice and clean.

I bought in LA and drove to San Francisco and must say, I was a bit disappointed with the freeway speed, but I could live with it. It was my first experience driving a diesel and my revs were often getting close to 4k while only maintaining speeds of about 110km/h - very slow on CA interstate 5.

Anyway, since getting it back here to SF I have noticed a significant loss of power. Lucky to top 100km/h on highway, revs much lower, and loses speed on hills. On some of SF's steeper streets I can't even hit 20km/h in first. Other than the power issue, it runs very smooth, no smoke and relatively quiet.

It took MANY phone calls to find a mechanic willing to even LOOK at it and the one who did definitely thinks there is an issue potentially with thermostat, turbo or both. Temp gauge is barely going above cold even after driving over an hour. Also, like I mentioned, everything under the car is quite clean, but the turbo is looking quite oily. Could I have blown it pushing to hard on my LA>SF drive? Quite an expensive first repair and seems like it will take a few weeks to get a new turbo.

Not to mention, it will be difficult to get this thing registered in California. It currently has oregon tags, but California doesn't make import ownership as easy as everyone else.

I really think the Delica is a close to perfect vehicle and uses interior space way more efficiently than my toyotas, but worried that it will be a bigger headache and money-pit than it's worth.

Any advice is greatly appreciated and I'd love to hear from some fellow US Delica owners. Thanks!!!!

deli-01.jpg (148.46 KiB) Viewed 4782 times

[team_ream]

PS. I'm learning but currently not very handy in the automotive realm.

[Growlerbearnz]

First up: welcome, and that's a good looking van!

4000rpm at 110kph is definitely not right, and (hopefully) just means you're in 3rd gear. There's a button on the automatic shift lever labelled "overdrive"- it should be pushed in, and the warning light on the dashboard (below the PRNDL) should go out. With the overdrive on you should be doing 2700rpm at 110kph. Usually you'd only turn the overdrive off if you were going up a long hill, as diesel engines run cooler when revving higher- but not as cold as yours! Which brings me to...

It sounds like you might not have a thermostat installed, but first you should check that it's not just a broken temperature gauge. Go for a drive for about 10 minutes and then feel the top radiator hose. If you could burn yourself by holding onto it too long then engine temperature is ok and the temperature gauge is broken. If it's just lukewarm, then you'll need to check the thermostat. With a functioning thermostat installed, the engine should warm up in about 5 minutes, you should be able to burn yourself on the radiator top tank, and the gauge will run in the 1/4 to 1/2 range. Diesels don't make much power when the engine is too cold.

Regarding the oily turbo, I have a theory: There's a small tube that connects the turbo to the fuel injection pump, so the pump knows what pressure the turbo is running at and can inject more or less fuel to compensate. If that hose pops off at the turbo end, the pump will not inject enough extra fuel and it'll be very slow. Also, oil will come out the disconnected fitting on the turbo and make a mess. Here's what the tube looks like with the engine cover open:

4D56boostTube.JPG (52.03 KiB) Viewed 4768 times

And here's where it goes when it disappears under the drivers seat:

4D56tube2.jpg (70.66 KiB) Viewed 4768 times

There's a whole heap of parts not installed on the second picture, TBH it's a bit of a nightmare in there. The best way to get at the turbo is to remove the drivers seat, fold back the carpet, detach the handbrake and fuel flap cables, then remove that section of floor. Check both tube fittings, add small hose clamps if necessary, check the tightness of the hose clamps on the turbo's outlet. Check the large bolt on top of the turbo that holds the oil feed pipe in place, but *dont* overtighten that one- it's a hollow bolt and will snap off if you're not careful. A torque wrench and a workshop manual from the FAQ/downloads section is your friend. Or maybe find an actual friend who has some mechanical experience

Driving from LA to SF at 4000rpm *shouldn't* have broken the turbo, and if it had the oil would be on the inside of the engine, but it's a really *really* good idea to figure out where the oil is coming from and fix it.

These engines are very basic, strong, and reliable, as long as they're assembled correctly. It sounds like yours might have been put together a little bit poorly- fix the issues and there's no need for it to be a money pit.

[Growlerbearnz]

Here's a more realistic picture of the tube on the turbo side:

4D56boostTube3.JPG (72.59 KiB) Viewed 4767 times

Eww.

[team_ream]

Thanks Growlerbearnz! This is all very helpful and will give me something to do over the weekend!


As for my high freeway revs - that was only happening when very heavy footed (as I tend to be). A slight decrease on the accelerator would result in 2500rpm with little or negligible loss in speed, which I'm guessing was 4th and tranny was going into 3rd when I was flooring it. Now it won't do that. It can get into 4th after awhile and O/D on/off works, but really limited on speed, only hitting 110 on a downhill and slowing to 50-60 on mild inclines. Doesn't seem to downshift when I floor it. Does that add any insight to your diagnosis?

[Growlerbearnz]

Yup, now it sounds even more like the injector pump isn't adding extra fuel when the turbo's on boost. I'd ask if you hear any unusual hissing noises when driving hard, but that depends on knowing what normal sounds like.

It definitely sounds like you're low on power, and having to hold your foot on the accelerator so hard that the transmission thinks you're trying to downshift. It's possible your transmission downshift cable is maladjusted (look for the orange boot on the injector pump) but I suspect it's more related to the low power. The only time the transmission should shift to 3rd on its own is when you're passing (like that's ever going to happen) or slowing down. If it shifts to 3rd on a hill you might be trying too hard. Which reminds me:

One important thing about our primitive diesel engines is that if you hold down the accelerator too far for too long, it's possible to inject more fuel than the engine can use, which overheats the head and turbo. This is a very bad thing. Basically, if pushing the accelerator more doesn't make you go any faster, then ease up. If you're flooring it up a hill but the van is still slowing down, you're doing it wrong.

[team_ream]

OK, so I checked both things that you recommended.

1. Though I couldn't see all the way to turbo, I followed the hose with my hand and it appears to be firmly fastened to the turbo. Anywhere else the oil might be coming from?

2. After driving home from work (about 10 minutes in the city) I felt radiator hose and was able to keep my hand on it indefinitely . Temp gauge did not get above the cold hash mark, though it slightly moved up from the very bottom.

FYI, the downshifting isn't happening anymore. That was happening when the van seemed to have more power. Now it gets into 4th but can't really accelerate much from there. Will downshift when I turn O/D off, so it def makes it all the way to 4th.

Would the next logical thing be to replace my thermostat?
Thanks!

[Growlerbearnz]

1. The oil could be coming from the turbo's outlet- it's connected to the inlet manifold by a short rubber pipe, and if the hose clamps aren't tight enough oil can leak out of there to make a mess (point A on the photo). it could also be the oil feed into the turbo- which is behind a heat shield, so you can't check it easily, but I'd expect the oil to be dripping down from the centre part of the turbo (point B). It could also be the typical valve cover leak- that oil can end up anywhere. Note that my turbo is on a slightly different angle to yours- point A is not going to be that easy to see.

2- Sounds like your temperature gauge is correct and the thermostat needs changing (or installing, if it's not there). Conveniently, the thermostat is down by the turbo so you can check all the turbo's other hose connections while you're there. Or inconveniently, if you were imagining an easy job.

The thermostat housing is at the top of the lower radiator hose, it's held on by two 12mm bolts. You'll need a new gasket as well as a new thermostat. Since you'll be cross-referencing at the parts store it might help to know that thermostat and gasket kit is Mitsubishi part number MD997606, gasket alone is MD149407.

I'm beginning to think your transmission is ok, it's the lack of power that's messing things up. There are a couple of other things to check on the turbo- like the wastegate. The rod in the picture should have some spring tension on it holding the wastegate lever up/closed- if you pull down on the rod (hard- it's under quite a bit of tension) you should be able to move it and open the wastegate. When you let go the wastegate should close with a click or snap. Sometimes the split pin holding the lever and rod pivot together falls out and the wastegate can just flap open, which means no boost.

DeliTurboBelow.JPG (419.68 KiB) Viewed 4738 times

Another thing to check would be the boost compensator diaphragm on the injection pump- where the boost hose goes in, the top cover is held on by four 10mm bolts. Lift the cover off, mark the diaphragm so you can replace it in the same orientation ("reference mark" in the picture), and lift the diaphragm out. Check for splits or holes in the diaphragm. (ignore "stop screw" on the attached photo- we don't have one of those). If the diaphragm had a split, then the boost signal would also be lost.

diaphragm.jpeg (10.92 KiB) Viewed 4738 times

[team_ream]

HI and thanks again for your help. I'm learning a lot, but still a total noob and thus, at the mercy of my mechanic. Being in the US without quick access to parts, it can be trying, but I want to believe!!!

Here is the update:
I failed at swapping the thermostat myself. Couldn't get around the bracket that holds up the power steering pump or get it off, so I put it all back together and took it to my mechanic. He swapped thermo and adjusted throttle and tranny cables, resulting in much better performance. However, turbo still leaking lots of oil and suggested I swap out.

Got new turbo and had it installed, then learned I need waste gate. Had that done as well.

Noticed zero difference in performance afterwards and maybe even a bit of a decline. Also, noticed the following day that i was getting black smoke on startup and acceleration. Also only getting about 26Kpg.

Brought it back to mechanic to be told i need a fuel injector pump (starting to feel like a money pit at this point). Anyway, I plan on ordering the pump tomorrow. John at Rocky Mountain Imports mentioned it could be the glow plug controller, but the previous owner replaced that, so hoping the pump will solve the problem and keep me out of the mechanic's garage for awhile.

Just curious what some of you pro's think. Are we chasing this thing down properly? Thanks!

[Growlerbearnz]

It sounds like your mechanic is on the right track.

You mention that a new wastegate actuator was installed- I wonder if it has been adjusted to give enough preload? The actuator should be adjusted so that it holds the wastegate shut quite firmly. About half an inch of preload is normal.

Most injection pumps only need a rebuild if they're leaking. Black smoke at idle (and a little when driving around) is more usually a sign that your injectors are clogged and need rebuilding- any diesel shop should be able to test the injectors and diagnose them. I'd do this first before rebuilding the pump- injectors are cheaper than a pump, and a new pump will probably need new injectors anyway.

Black smoke at idle and "rolling coal" when accelerating might be caused by a previous owner adjusting the full load fuelling adjuster on the injection pump, possibly in an attempt to get more power (due to the failed wastegate actuator?). You said the accelerator and transmission cables needed adjusting- that means that someone has been messing about near the pump. While a rebuilt pump *should* solve this problem (re-setting all adjustments to factory spec is part of the rebuild process) it's unlikely that the pump *needs* rebuilding. I would take a look at the full load adjusting screw. It should have a tamper-proof cover over it. If the cover is missing, then I'd try adjusting the screw to inject less fuel overall, and see if that helps. ( I don't recall which direction to turn it, but if you're going in the "less fuel" direction your idle speed should drop. You'll need to re-set your idle speed.)

The glow plugs only help start the engine when it's cold- after about a minute of running they don't do anything. If the engine's running badly when cold, the smoke tends to be white or grey, not black.

[Killbert]

I recommend teeing in a boost gauge and checking for proper boost under load. I think it should be around 11 psi. You can Tee into the line that runs from the turbo side to the top of the pump. It's the line for the pressure diaphragm. Might as well permanently install a boost gauge.

K

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