1HZ engine issues in two 70 series cruisers - HZJ78 and HZJ73

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HJZ73Beast

HJZ73Beast

Joined
Jun 9, 2016
Threads
2
Messages
5
Location
United States
Hi folks, need little help from anyone familiar with the 1HZ engine. We are 4 people from the UK, travelling across the USA in two 70 series cruisers - a HZJ78 and a HZJ73. We got to Blanca, Colorado and have both hit pretty bad engine issues, unbelievably at the same time. I will describe the problems and hopefully someone can offer some knowledge... Firstly the HZJ78 - It has been losing power and kicking out white/grey smoke for some time. We drove up through the first ascent in the rockies and it basically lost all power, wont go over 40mph, and there is a discernable knocking sound coming from the engine. We have bypassed all fuel lines & filters to check for blockage and no change. We went to a mechanic and he diagnosed it as an injector issue with a stethoscope, as number 3 & 5 injectors have a distinctive 'Cow bell' sound when listened to. We have changed all 6 injectors for brand new ones and the problem is worse if anything - still kicking plumes of white smoke, no power, and the knocking sound in the engine is worse. Strangely the 'cow bell' noise in 3 & 5 injectors remains the same as before we changed the injectors...

The HJZ73 has a similar issue but not as severe - It has a loud knocking noise which is coming from the underside of engine, but also seems pronounced around the Bellhousing (not sure if this is just noise transfer) it is losing power too, but less so than the 78. When diagnosing with the stethoscope, it too has the distinctive 'cow bell' noise from number 3 injector.

We are currently stuck in a windy campsite in Blanca, so the amount of investigative work we can do on the engine is limited because of dust contamination. Any help or advice would be very much appreciated, whether it's people's experience with this issue with the 1HZ engine, advice on what it can be, or advice on any good toyota/diesel mechanics in the Blanca, CO area.

Thanks in Advance!

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Just talked with someone on the phone about this a few minutes ago.

Blanca is kind of boonie, not too bad though. I-25 is not too far away.

Red Line Land Cruisers in Colorado Springs would be a logical option. @RLMS

Robbie Antonson in Boulder, CO knows these engines well and is a great diesel mechanic. But might be a bit far.
 
If both trucks started plying up around the same time I think you guys picked up bad fuel from the same service station you need to drop a few liters from both tanks and look for water contamination. It's easy to check craw under the truck with a bucket and unscrew the drain bung but it does get messy trying to get the bung back in so where some rubber gloves.
Good Luck
 
Contamination to both? Either bad fuel, or coolant issues? My first instinct is head gasket too.
Drain everything and have a look would be first advice. Best of luck with it, keep us posted. J
 
I was following this earlier on the facebook TLCA. Apparently they fueled up separately at two different stations. There was a lot of talk about altitude causing the issue. If your on FB check it out. It is pretty cool to see the community jump in to try and solve the issue in real time. It will be interesting to see what the verdict is.
Toyota Land Cruiser Association (TLCA) Public Group | Facebook
 
If the trucks filled up at different fuel stations and are still having similar symptoms I would guess altitude is an issue especially if these trucks were tuned for sea level. Blanca CO is over 2300 M high. I would try turning down the injection pumps and see how the trucks run. Over fueling can create a lot of strange symptoms.
 
2 1HZ's having similiar symptoms at more less the same time...most likely points to an environmental/external factor. pump setting, altitude, bad fuel, heavy rigs, or a combination. The white smoke being un-burned fuel and the knocking being lack of combustion.
Paging @Jan-78FJ40 and West Coast Cruisers Michael for input...
 
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I missed two trucks simular sounding noise.. fuel filters first as I have heard a plugged 1hz filter and it makes a nasty cow bell sounding thud .. second as mentioned altitude.. Pretty sure BEBS do not both go at the same time;)
 
Unless who ever serviced these trucks used the wrong oil then both could fail around the same time with big end problems. We need more info on these trucks to help diagnose. I was thinking high altitude causes black smoke not white or grey but to be honest I have never had this problem downunder as no mountains only hills where I live.
 
HJZ73Beast said:
Hi folks, need little help from anyone familiar with the 1HZ engine. We are 4 people from the UK, travelling across the USA in two 70 series cruisers - a HZJ78 and a HZJ73. We got to Blanca, Colorado and have both hit pretty bad engine issues, unbelievably at the same time. I will describe the problems and hopefully someone can offer some knowledge... Firstly the HZJ78 - It has been losing power and kicking out white/grey smoke for some time. We drove up through the first ascent in the rockies and it basically lost all power, wont go over 40mph, and there is a discernable knocking sound coming from the engine. We have bypassed all fuel lines & filters to check for blockage and no change. We went to a mechanic and he diagnosed it as an injector issue with a stethoscope, as number 3 & 5 injectors have a distinctive 'Cow bell' sound when listened to. We have changed all 6 injectors for brand new ones and the problem is worse if anything - still kicking plumes of white smoke, no power, and the knocking sound in the engine is worse. Strangely the 'cow bell' noise in 3 & 5 injectors remains the same as before we changed the injectors...

The HJZ73 has a similar issue but not as severe - It has a loud knocking noise which is coming from the underside of engine, but also seems pronounced around the Bellhousing (not sure if this is just noise transfer) it is losing power too, but less so than the 78. When diagnosing with the stethoscope, it too has the distinctive 'cow bell' noise from number 3 injector.

We are currently stuck in a windy campsite in Blanca, so the amount of investigative work we can do on the engine is limited because of dust contamination. Any help or advice would be very much appreciated, whether it's people's experience with this issue with the 1HZ engine, advice on what it can be, or advice on any good toyota/diesel mechanics in the Blanca, CO area.

Thanks in Advance!

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i would highly advice to check compression for lost of power to make sure internal basic are in good shape. then go from there to clearified symtoms step by step.white smoke are normally the sign of unburn fuel, injectors may cause this issues, injection timing-late injection timing may cause this problem- could be injection pump waren down too much where there is not enough advance timing on higher rpm,valve clearances- too tigh causes lost of compression and all these can cause bad flame speed to full utilise frame speed for maximimum power when needed. so good luck with these and keep in mind the above advice,who ever works on it.
 
Ok check your oil level.
Is there any change in level (fuel dilution)
Oil analysis is worth the cost. Can tell you what's going on sometimes.

I would check your injector pumps health. Chances are they have never been done, the timing is really important to look at. Expect a 13-1500 bill alone for just a pump.

If that isn't the fix, I would try and pinpoint the issue more, lots of possibilities but white smoke usually means an injection related issue.
 
so i had the same white plume smoke and power loss passing from denver to grand junction over the pass. White smoke means either the air/fuel mix is lean or coolant. I had the same power loss as you at the top of the pass and was smoking when accelerating. Thought i cooked her!. As soon as i came down from 8k feet to about 5500, the smoking stopped and i had power again. Look up high elevation white diesel smoke and there are tons of info out there. Good luck!
 
Right, lean on air. Higher altitude means less air/oxygen. If the pump is still giving the same amount of fuel per its adjustment, then there is more fuel in the mix. Lack of combustion would be due to the extra fuel rinsing/drowning the combustion and really not combusting at all, in this case. Hence the high altitude compensators. Does a 1HD-T boost compensator solve this issue, or is that only for the turbo @ForealBoreal?
 
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1tontoy said:
Right, lean on air. Higher altitude means less air/oxygen. If the pump is still giving the same amount of fuel per its adjustment, then there is more fuel in the mix. Lack of combustion would be due to the extra fuel rinsing/drowning the combustion and really not combusting at all, in this case. Hence the high altitude compensators. Does a 1HD-T boost compensator solve this issue, or is that only for the turbo @ForealBoreal?
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A boost compensator simply increases fuel delivery with the input of turbo boost.

Some 1hz pumps came with a high altitude compensator. My stock pump did, though my dads hzj73 did not come with one. The way I understand it is that the altitude compensator defuels.
 
Guys, thanks for all your responses.

You can read the entire breakdown of where we're at so far on the facebook thread, as well as a video showing the exact issues on the 78, including the 'cowbell' noise in numbers 3 & 5 injectors.

A few key facts you were asking about -

1) We fuelled up at two different stations, one in Oklahoma, the other in Kansas, so cross contamination unlikely.
2) The vehicles were serviced at the same time, 4500 miles ago, with 15 40 semi synth oil.
3) The 78 has an altitude compensator, the 73 does not.
4) The 78 was exhibiting power loss & white smoke symptoms before we ascended the rockies, but when we did ascend, the symptoms got drastically worse.
5) We have checked the fuel pump timing which is good.
6) The air filters are both new K&N and in good condition.
7) We're fairly certain it's not a head/head gasket issue, as there is no pressure at radiator/no overheating/no loss of coolant/no contamination in oil.

So that's where we're at so far. There is one strange common factor on both 78 & 73 - When we listen to the number 3 injector with a stethoscope, they both have the distinct 'cowbell' sound. (see video on the link) Could anyone else with a 1HZ have a listen to theirs, and let us know if this is just the way the number 3 injector sounds on 1HZ, or of this is a common denominator and a clue to our problems?

Many thanks again for all your responses so far!

Toyota Land Cruiser Association (TLCA) Public Group | Facebook
 
If you put your fingers around each injector line near the injectors you should be able to feel a distinct tapping type pulse. If any cylinder does not have this tapping pulse that will be the cylinder low on compression causing the blue smoke and lack off power. My guess is this engine needs new rings
 
Let's get a few things sorted out here:

How much mileage on these vehicles & engines?

1HZs don't typically have problems with the Big End Bearings (aka BEBs) that I have encountered yet. I wouldn't be looking at this or catastrophizing quite so quickly.

Contaminated fuel can and does cause hot running, low power, smoke - generally if contaminated with gasoline. It's surprisingly common when people are not paying attention to the fuel pumps in unfamiliar places.

1HZs can and do have head cracking problems from time to time, but it's usually due to neglect rather than anything else. Don't overheat it, keep your EGTs in check, and don't run it low on coolant - pretty easy to do and keep these engines alive.

EGRs, if equipped, can case loss of power and smoking issues when they get stuck open.

K&N air filters.... I do not like these filters in any way, and they do not belong on any kind of off-highway vehicle, but it's not likely the source of your problem.

I have had loud knocking in these engines when there are issues with cracked pistons or cracked rings/ring lands from detonation from overheating, poor injector spray patterns, or when exposed to aerosols from degreasing agents when the engine is running (which can cause terrible detonation as 'added fuel'). I wouldn't be looking for this first, I'd be looking at other issues - the simpler ones, like contaminated fuel.

White smoke, when not related to coolant consumption/head cracking issues, is then usually related to fuel timing and fuel delivery volume, or fuel quality.

We also see a similar problem in quite a few of the 2LTEs when there are issues with pump advance/timing or stuck injectors (among all the other issues that 2LTEs seem to have all too often).

I'd look for the simple little things first - Occam's Razor and all that - before looking for the big things that are more complex.

~John
 
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