Is Injection pump working too well?

Got a. 1991 Hiace LH119 here. I posted a few months back about how I sent my Injection pump off to be rebuilt and USPS lost it. Long story short, they never found it. Luckily  I was able to find a rebuilt one in Australia ( I’m in California) and had that one installed by my mechanic.

Now with the new one installed, I have noticed my mpg has gone noticeably down, it smells overalls “diesely”, and the idle seemed to be higher then before.

Is it simply that the pump needs to be adjusted, like it’s pumping too much fuel? Thanks for any help.

I'm told the fuel adjustment is very touchy, you might try turning it a small amount and see what difference it makes, if worse try a bit in the other direction. Something like just a quarter turn, no more than that, also I heard that tightening the lock nut is inclined to move the adjuster so you have to keep a firm hold on that while tightening the nut.
I'm not a diesel mechanic, I'm just repeating what I've read elsewhere so treat this with caution.

I dont have one or any knowledge of toyota diesel engines, but if its like the standynes on gms there is a screw behind a cover that adjusts the fuel amount. It is very touchy, like an 1/8 th of a turn is a huge difference!

I think it's just on the side of the pump somewhere, fairly reachable.

Thanks all, I’m currently away from the Van but gonna do the adjustment first thing when I return and give y’all an update. I’ll
Try and take some pictures too.

Murphy's law of course dictates that whichever way you at first turn the adjuster will be the wrong way so will make things worse.

I finally got around to adjusting the fuel adjustment screw. Prior to adjustment I was getting a lot of white smoke blowing out the exhaust system and also a reduced MPG.

I adjusted the screw counter-clockwise which reduces the amount of diesel through the injection pump. When you turn it, you can audibly and visibly see the rpm’s lower. I thought this would remedy the problem but I’m still getting white smoke dumping out the tail pipe even after lowering the fuel amount. Any thoughts? Thanks

Ooh white smoke not black, that sounds like coolant leaking into cylinders. Too much fuel would be black smoke. Head gasket gone?

I checked coolant level and it is still full so I’m assuming that it isn’t head gasket but I will monitor level. I’m gonna try and tinker more with the adjustment of the fuel to see if the situation changes. Thanks

Hello and sorry to hear of your woes.

This is worth a read as there could be related problems: https://learndiesels.com/diesel-smoke-guide/. I can’t comment on all of these but can offer a few pointers that are hopefully useful.

If you are confident enough to remove and replace an injector pump then I take it you have already run quite a few other diagnostics and tests.

If you didn’t have comparable smoke before the new pump then it could be pump related, or related to its timing. I’ve not removed my pump, but probably will do so for some other work so am keen to learn from your experiences if I can.

Can you be certain that the new / reconditioned pump is good, and is it and its settings as close to original as possible? Here I mean the throttle, idle and advance lever settings? Did you take measurements of these for the old pump that you can transfer for setting up the new one? Did the pump come with any certification?

Is the engine a 3L and is the pump to engine timings correctly set to the pump fuel delivery with the valves etc. I used to have a Peugeot diesel that had a manual belt-driven pump like the Toyotas and it was possible to tweak the injector pump timing (at idle) by loosening off the mounting bolts and rotating the pump by a couple of degrees while the engine was running. This moved the fuel injection timings and you could hear and see the difference and find a sweet spot. On ‘seeing’ the smoke colour and amount changed and in ‘hearing’ the degree of knocking changed from unacceptable to sweet to odd.

The other thing to reference is the other timing elements within the engine, such as the crank to cam (plus the fuel timings as above). Can you see and check the alignment of the crank and cam to be sure there isn’t a jumped tooth? When my timing belt was last changed the mechanic painted small dots on the sprockets and belt and when I change it (shortly) I’ll be doing the same and counting the number of teeth between the sprockets. An incorrectly set engine might self-destruct and I don’t know the tolerances, but it will certainly not burn fuel properly.

Here the engine timing sticker for mine:


The next thing to consider is that if there was no smoke before has something gone wrong with the engine while off the road? Has something foreign got into a cylinder and damaged something, or has a ring failed? While hopefully this is not likely, a compression or leak-down test should reveal if there is low compression somewhere. Or a valve open, but this should be obvious in other ways. Or cylinder head / gasket with coolant mix. There are chemical tests for combustion gas in coolant but a cylinder head gasket problem is usually evident with coolant level dropping / over pressurisation or bubbles in the coolant. If you do a pressure test I think it should be preceded by a visual inspection of each cylinder when at its BDC. I do hope this is all unlikely.

Sorry to give you a list of possible problems and the link suggests a few others, too such as air in fuel and air restriction. These should be fairly easy to eliminate I hope.

Lastly I’m guessing the smoke is white; it’s not easy to tell from the pictures. You write that it smells ‘diesely’ which is poss better than sweet (coolant) or oily (well, oil obvs). Good luck with your endeavours, please update here and be methodical.

HTH

Thanks for the reply. I’ll try and answer your questions as best I can.

To provide some context the story goes as such: I noticed a significant diesel leak, took to a shop. They removed the injection pump, likely not taking note of the throttle, idle, and advance lever settings. I sent injection pump through usps to be serviced and it was lost forever. I found the exact pump in Australia, they rebuilt, tested and sent it back to me. I’ll add a picture. The shop then fitted it right back on. They also did the timing belt at that same time.

Since then, it ran fine, but I did notice lower MPG and a significant smell diesel while running, but no smoke besides the usual black puff.
Now I’m noticing the smoke has turned this white color as shown above. Maybe it’s got a hue of blue but I can’t be sure. What I do know is that my coolant level is fine BUT my oil level seems to be dropping. That could be from a slight seep I have but I still need to trouble shoot this.

The engine is the 3L and am about to go take it for a test drive after adjusting fuel screw to see if I still get bad smoke on acceleration.

Hello.

That looks like a very tidy pump and its appearance suggests care and attention in the refurbishment.

There might be a number of unrelated issues that have appeared close together since you say the while smoke problem didn’t occur when the belt and pump were added. It also sound like everything is buttoned up so now harder to check, test and adjust.

I also have a 3L engine but it’s not in a running state. If you need any static measurements or pictures let me know. The full engine manual is Toyota publication RM123E, which occasionally appears for a lot of money on eBay, but I don't have a copy. There are plenty of other electronic resources for engine manuals out there including: https://www.hiacesoutheast.com/hiace-manuals.

This link has the best manual I’ve found for electrics, but I think your issues are very mechanical. The link is also a good source for engines and other mechanicals, which I hope you find useful, but expect you've already found it. I've a few other engine manuals so ask if you're stuck for other sources.

Cheers