‘93 Hilux Surf 2lt-e rough start up and black smoke

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Hello,

I own a 1993 Hilux Surf SSR-X 2lt-e.
I recently replaced the head (big surprise, I know) and now it starts very rough. When I first start it for the day it spews white smoke and idles very roughly for a minute or two. Once it is warmed up it consistently bellows black smoke.

I assume that I either am getting too much fuel or insufficient air.

In the last months I have replaced the injectors, o-rings and seals on injection pump, fuel rail, glow plugs, head, gasket kit, radiator, and thermostat.

if anyone has an idea as to what I might be experiencing, I welcome all feedback.

Thanks so much!
 

GTSSportCoupe

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Is your EGR emissions system still intact? Chances are pretty high that it's not working right. If the VSV's are not plugged in, or if vacuum supply is not connected right or leaking (or other problems), then the system can starve your engine of air.

The main reason your engine has a throttle plate is to create a vacuum at idle that can be used to draw in gases from your exhaust (EGR system). It should only do this when the motor is hot and idling though. When working right, the computer can open a secondary small throttle plate to allow air by when the engine is starting or still cold. If this small throttle doesn't open, then your engine will run as you describe.

My recommendation, remove all the EGR stuff and remove the large throttle plate from your throttle body. DO NOT remove the throttle shaft or adjust/remove your throttle position sensor though. Fabricate block off plates to cover the holes where your EGR pipes used to be at the exhaust and intake manifolds. There are a few 'how to' threads on this in these forums.

If you don't want to do all that work, you can disconnect the secondary throttle linkage, and force it to stay open with some wire. Or you can force the vacuum actuator to keep it open all the time by switching vacuum hoses around (remove VSV's from the loop so they can't do anything any more).

I think the EGR system is a big part of the problem these motors have, as it really limits the air supply causing them to run hotter and not cool down properly. The EGR soot mixes with the PCV sludge and plugs up the intake manifolds too.

Now, if you have removed your EGR system already, I can give you some other ideas as to what may be causing your problems....

Good work on all the things you've done so far!

If you really want to understand the EGR system better (and the engine in general), I highly recommend reading this manual.
 
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Wow. This is great.

Thank you so much for your detailed response!

I would love to read this manual. Can you send a link?

I will keep you posted on what I find.

Thanks again!
 
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One more thing:

I first brought my Surf to a mechanic who over-confidently took it apart but was unable to put it back together properly. I have since then reassembled everything but am left with a couple questions.

The bigger one is what is supposed to attach to this? It seems like a vacuum line but I followed a 2lt-e vac diagram and didn’t see anything about it?

8FCA5202-EB73-4FFF-BF84-8BDC401BE199.jpeg
 

GTSSportCoupe

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One more thing:

I first brought my Surf to a mechanic who over-confidently took it apart but was unable to put it back together properly. I have since then reassembled everything but am left with a couple questions.

The bigger one is what is supposed to attach to this? It seems like a vacuum line but I followed a 2lt-e vac diagram and didn’t see anything about it?

View attachment 2761564




FYI: I posted the manual in my first response above. Should be displaying as a big PDF...no?

What you've circled is your problem. That's what I was talking about in my post above.

Go to Megazip, look up your LJ78 exact year and look through the drawings. You'll find one that shows all those vacuum hoses and where they should go.

I can't help you using mine as an example, as I ripped all that stuff off my motor a decade ago now.

Maybe someone else here with an intact EGR system can take some pictures for you though?
 
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So I was digging through old photos hoping to find the vacuum line that goes to this. I found a photo but it’s not a vacuum!

it may just be a fancy plug? I doubt that’s the case though. Do you have any idea what this cylinder does or where to find one? My mechanic SWEARS he doesn’t have mine.

D5CF3D07-4903-4B4B-83F1-5EE4EAC4EF2A.jpeg
 

GTSSportCoupe

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So I was digging through old photos hoping to find the vacuum line that goes to this. I found a photo but it’s not a vacuum!

it may just be a fancy plug? I doubt that’s the case though. Do you have any idea what this cylinder does or where to find one? My mechanic SWEARS he doesn’t have mine.

View attachment 2761775



Ahhh, sorry, I see now. That is just the vent for the VSV; the filter is missing is all.

In any case, I think this area is where your problems may be. Check that the vacuum line from the vacuum pump (attached to alternator), connects fine over the top of the engine to supply vacuum to your emissions equipment.

The little UFO looking thing in your first picture above on the left is a vacuum actuator that opens/closes the little valve in the throttle body I was talking about. You need to make sure it is keeping the little valve open when the engine starts and is cold.
 
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So all vacuum lines seem to be fitted properly. After loads of more research I’m starting to suspect I have an issue with my glow system. My mechanic had the glow system hooked up INCREDIBLY wrong. I thought that I had finally figured it out but am now second guessing myself.

Does anyone have photos of their busbar post? I saw that someone said “both wires” but I only seem to have one wire going to the post.
Any photos would be awesome!

image.jpg


image.jpg
 
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So I just tested my (brand new) NGK glow plugs for power. I put the positive lead of my multi meter to the glow plug directly and the negative to the battery ground.

When I switch the key to heat the glow system, multi meter will read 3-5v for about a second and then read zero.

The car does start so I assume the plugs are working in some capacity?

At this point I am assuming that I am either missing a connection or have shorted a relay somewhere. Is it possible my


My (now ex) mechanic didn’t know how to hook up my glow system and ended up bolting the power wire for the busbar to the side of my intake manifold. I assume he thought it was a ground wire? Could this have shorted something? I have replaced the relay near the fuel filter as well as the resistor in the I take manifold with OEM toyota replacement parts.

I’m feeling pretty stuck at this point.

I also got both batteries tested yesterday and they are each in need of replacement. 350CCA on one and 400CCA on the other. The car starts so I assume the battery is not my issue.

As always, any info/incite is incredibly helpful.

Thanks!
 
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Disregard all I’ve said about glow plugs not working. I had my multimeter on the wrong mode… sorry for being a total noob.

GTS,
How do you propose I ensure that the valve in the throttle body is open on cold start? Is there a way to test this?

also, what is the “secondary throttle cable” doing? It seems to have slack in it?
I saw a forum saying to check that upon full extension I should see 1mm of stopper coming out of the rubber sleeve on that cable. I have that.
 

GTSSportCoupe

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@pnwhilux

It sounds very possible that your glow system may have been damaged by your mechanic grounding it out. I actually made the same mistake long ago on my truck, and it blows a 'fusable link' near the battery positive.

Anyhow, to properly test your glow system, you need to start with a cold engine, and have an assistant. Hook up your voltmeter as you've described. Make sure you're clear of fan/belts. Have the assistant turn the key to 'on' while you monitor your voltmeter. You should see ~11V for about 7 seconds or so, and then hear a relay shut off. Have the assistant start the engine at that time. Keep monitoring the voltage, and you will see an after glow voltage around 5-6V for another 30sec-1minute or so. If it doesn't work this way, let me know and I can give you some ideas of what might be happening.

Generally though, your smoke issues will most likely be from one of these things:

1 - EGR system butterfly not working right and starving motor of air. The motor will be smokey for a long time after starting if this is the issue.
2 - Glow system not pre-heating the engine, making it difficult to start and smokey once it starts. The smoke should go away quickly once started if this is the problem.
3 - Low compression on one or more cylinders leading to missfiring and smoke. Smoke should go away quickly once the motor is firing on all cylinders.
4 - Air in fuel lines. Likely from a leaking primer pump, leaking fuel line/hose. This can cause your engine to missfire and smoke until the air has worked it's way out.
5 - Injection system issues such as faulty/damaged injectors or injection pump.

You just need to eliminate one thing at a time. EGR should be easiest to eliminate, as is the glow system. Compression is a fairly easy test. Where air gets into the fuel system, usually diesel gets out, so look for 'sweating' diesel. Injection system will be most complicated to test.

Regarding testing your EGR secondary valve as a potential problem, you just need to force it open and start your motor.

Here are a couple pictures I found that show what I'm talking about. First one shows the main and secondary (emissions) throttle plates with the intake neck taken off. In the second picture, the thing the guy is hold is what actuates the secondary throttle plate, and his fingers are on the throttle shaft that you will need to monitor (or force open).

You can force that throttle plate open just by attaching a vacuum line to the actuator. Or just remove the actuator so you can open/close the valve manually. Or, remove the intake neck, and unscrew and remove the little emissions plate. Or just visually monitor it when the motor is started. So many options.

image-jpg.1361652


img_2489-jpg.1361731
 
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Hello again!

So I’ve tried everything we’ve discussed and have had no luck thus far.

I repúlales my injectors and sent them back to the rebuild shop to make sure they weren’t faulty (they were not).

I am now curious if the people I bought my ln130 from had adjusted the fuel enrichment screw to compensate for problems they were having. And now that I have replaced and repaired all the known engine issues it could be running too rich.

My question to you is regarding the Enrichment Screw on the injection pump. I have read all the forums I can find but still seem to be lost.

I pulled the “thimble” off of the top of the pump and then removed the 10mm nut. I am then left with a VERY small hex-bolt. Is this what I am supposed to turn counter-clockwise? People are referring to it as a screw so I am a little confused.

Again, thank you so much for any and all help.

Cheers.
 

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