Intermittent Sluggishness 1997 HDJ80 1HD-FT

Toxicmasculinity

New Member
I am in great_britain
Aug 26, 2016
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Looking for some advice on the best way to diagnose some intermittent sluggishness I've been having. I drive my '97 HDJ80 most days and sometimes it pulls like a train and other time is struggles a bit.

I believe it might be a fuel pick up issue as I've noticed when driving up hill sometimes, it pulls very well then when flat an level again, not as well, but this is only on the odd occasion. It only seems to happen in lower rev ranges up to shifting into 5th and accelerating from 50mph which seems to be the magic number and up and around 2000rpm (could it be a turbo issue?) that I get smooth acceleration.

I'm quite keen to learn from other's experience and to find the problem myself and not take it into a garage. I've recently serviced the engine, so it has had a new fuel filter. I am now going to start at the tank and the pickup to see if I need to get a new strainer on the pickup and if there is any sediment in the tank that might be hindering fuel pick up, owing to the age of the vehicle.

Obviously if that doesn't help then I'll start looking at the injectors etc.

I would appreciate anyone's thoughts on the matter who might have had the same/similar issue.
 

stumog

Well-Known Member
I am in england
Oct 3, 2012
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Your spot on check pickup in tank.

When was the water drained off fuel filter?
 

Toxicmasculinity

New Member
I am in great_britain
Aug 26, 2016
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Your spot on check pickup in tank.

When was the water drained off fuel filter?
I changed the filter about 2 months ago and the the issue went away for the most part from what I could tell but has recently reared it's ugly head again.
 

Toxicmasculinity

New Member
I am in great_britain
Aug 26, 2016
20
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I changed the filter about 2 months ago and the the issue went away for the most part from what I could tell but has recently reared it's ugly head again.
Update.

I removed the fuel pickup to have a peek inside the tank and see if there was any blockages or sedement in the fuel which might be causing the issues I've been having, but to both my relief and dissapointment the fule pickup unit and inside of the tank look pristine.

I decided to syphon all the fuel out of the tank just to be sure I'm getting rid of any contamination/water.

Next step is to drain the fuel filter and put some fresh fuel in the tank and take it for a spin.

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Toxicmasculinity

New Member
I am in great_britain
Aug 26, 2016
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Update.

I removed the fuel pickup to have a peek inside the tank and see if there was any blockages or sedement in the fuel which might be causing the issues I've been having, but to both my relief and dissapointment the fule pickup unit and inside of the tank look pristine.

I decided to syphon all the fuel out of the tank just to be sure I'm getting rid of any contamination/water.

Next step is to drain the fuel filter and put some fresh fuel in the tank and take it for a spin.

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Grimbo

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Dec 3, 2016
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How recent is this issue ?
There has been loads of problems this late summer and autumn with Ag and Plant that seems to stem from the upping of the bio content in fuel from B5 to B7 . This seems to have scrubbed the inside of fuel lines and tanks resulting in fuel filters blocking ....an ongoing problem and some customers were having to change filters every 50-100 hrs or so when normal interval would be 600 or 1200 hrs . Try fitting another new genuine Toyota filter and see if the vehicle then performs as it should .
 

Toxicmasculinity

New Member
I am in great_britain
Aug 26, 2016
20
6
3
How recent is this issue ?
There has been loads of problems this late summer and autumn with Ag and Plant that seems to stem from the upping of the bio content in fuel from B5 to B7 . This seems to have scrubbed the inside of fuel lines and tanks resulting in fuel filters blocking ....an ongoing problem and some customers were having to change filters every 50-100 hrs or so when normal interval would be 600 or 1200 hrs . Try fitting another new genuine Toyota filter and see if the vehicle then performs as it should .
Grimbo, noticed it around August, I've only owned it since July and I have since changed the filter when I serviced it about two months ago, albeit not with a genuine Toyota filter. I will try the genuine filter and see what happens from there.

Thanks for your advice!
 

nielsc

Well-Known Member
I am in belgium
Jun 28, 2016
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I'd check next for air being drawn into the fuel system. By leaking pipes/hoses or a failing primer pump.
If this would be the case then he has to hear his injection pump ticking loud.
Mine did, reason unkown, no air visible trough clear fuel line, so it had to be the lift pump being worn a bit, I fitted a inline electric fuel pump and problem went away, slightly more power too.
 

Toxicmasculinity

New Member
I am in great_britain
Aug 26, 2016
20
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I'd check next for air being drawn into the fuel system. By leaking pipes/hoses or a failing primer pump.
I'll have a look
If this would be the case then he has to hear his injection pump ticking loud.
Mine did, reason unkown, no air visible trough clear fuel line, so it had to be the lift pump being worn a bit, I fitted a inline electric fuel pump and problem went away, slightly more power too.
I don't have any ticking from the injection pump that nielsc described, at least not from what I can tell. Is there a way to test the lift/prime pump other than swapping it for a different one and see if the problem persists? I'll trace the fuel lines from the tank forwards nevertheless just to be sure.
 

Towpack

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Oct 4, 2011
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Also check the small rubber boost pressure hose from the turbo to the IP hasn’t come off or split. Do you have any means of checking boost pressure? With the engine not running try manually operating the lift pump with the priming button, it should go hard quite quickly after 2-3 pumps.
 

Toxicmasculinity

New Member
I am in great_britain
Aug 26, 2016
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Also check the small rubber boost pressure hose from the turbo to the IP hasn’t come off or split. Do you have any means of checking boost pressure? With the engine not running try manually operating the lift pump with the priming button, it should go hard quite quickly after 2-3 pumps.
Towpack, so far I haven't been able to locate any hose connecting the turbo to the injection pump and no, I don't have any means of checking the boost pressure.

The previous owner has deleted the EGR, and I'm still trying to get my head around all the rubber hoses and switches which connect to the top of the IP, which I'm assuming has something to do with the cruise control? Could anyone clarify this for me?

The two switches on the left are connected to the electrics, but no hoses attached, taking into account it's proximity to where the EGR used to be, leads me to believe that is what they were connected to. Of coarse the one in the middle and on the right and picture below that, I haven't got a clue what they are for.
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Circled below is a hose connected to the unit on top of the IP but I'm not sue where the other end goes.
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Inked20191026_145223_LI.jpg
 

Toxicmasculinity

New Member
I am in great_britain
Aug 26, 2016
20
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I'd check next for air being drawn into the fuel system. By leaking pipes/hoses or a failing primer pump.
Traced the fuel feed hose from the tank to the lift pump and on to the IP, but can't see any diesel spots on hoses themselves, I'm tempted to just replace both, just to be sure.
 

Grimbo

Well-Known Member
I am in great_britain
Dec 3, 2016
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Try the fuel filter first ....simple and easy .
All the little brown and blue solenoids you indicated are EGR related....
24v's are known for a flat spot or fueling issue at about 1800rpm on light throttle ....it feels like fuel starvation ,
This can be simply sorted and was an emissions related thing ....all about no black smoke as the throttle is floored .....mine passes every MOT with very low readings despite being tweaked and the EGR blanked
 

Toxicmasculinity

New Member
I am in great_britain
Aug 26, 2016
20
6
3
Try the fuel filter first ....simple and easy .
All the little brown and blue solenoids you indicated are EGR related....
24v's are known for a flat spot or fueling issue at about 1800rpm on light throttle ....it feels like fuel starvation ,
This can be simply sorted and was an emissions related thing ....all about no black smoke as the throttle is floored .....mine passes every MOT with very low readings despite being tweaked and the EGR blanked
Grimbo, if they are EGR related, can I do away with them then? Also I don't get any smoke when flooring it, so there's a positive I guess. The exhaust fumes are really strong though, even more so than what I've noticed from larger diesel engines I've been around to in the past, but I'm sure that's normal? I'm still new to the 1HD-FT, lol!
 

Towpack

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I am in england
Oct 4, 2011
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The hose I described "from the turbo" is actually this one from a take off just below the heater housing and takes boost pressure to the top of the IP. The small brass connector you can see just underneath my fingers is a take off to a boost gauge in the cab.
IMG_0541.JPG


This one, now disconnected and blocked off, is a vacuum hose for the EGR actuators...

IMG_0542.JPG


This one is for the PS and AC idle up actuators......


IMG_0540.JPG


I intended to remove the EGR actuators when I removed the valves but found it brought up an ECU warning light on the dash so left them connected electrically.

The "off boost injection volume" Grimbo speaks of is an easy one by adjusting the screw on top of the pump to the high spot of the cam underneath. Im sure theres a thread on here about this and other tweaks somewhere.
 

nielsc

Well-Known Member
I am in belgium
Jun 28, 2016
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One of them is the BACS (Boost altitude compensation) solenoid, the other is the SICS (Startup Injection Control) solenoid.

SICS gives more fuel when starting cold, this one you can disconnect and hook up directly to it’s vacuum source, this will give overall more fueling. It’s the one with the rubber hose going to the vacuum canister between the injection pump and engine block.

The BACS alters the movement of the boost compensator diaphragm to reduce or increase fueling depending on altitude.
The rubber hose goes to the rear of the injection pump, underneath the boost compensation diaphragm.
This one you can also disconnect, and leave the hose open, make sure it points down so no dirt or moist can get in it.
However It’s not necesary to disconnect this, and i believe if you do, it’s best to re-tune the boost compensator.


The ones on the right side of the engine are indead the vacuum switch valves for the EGR valves.
 

IRLGW

Well-Known Member
Dec 2, 2011
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3 Problems Noted...
1). Your Diesel is looks the wrong colour - its white so there could be some vital nutrients missing....

2). The rocker cover says 24v and not 12v...

3). Too many wires.

Have you checked the tank breather?
 

Toxicmasculinity

New Member
I am in great_britain
Aug 26, 2016
20
6
3
3 Problems Noted...
1). Your Diesel is looks the wrong colour - its white so there could be some vital nutrients missing....

2). The rocker cover says 24v and not 12v...

3). Too many wires.

Have you checked the tank breather?
Haha, you've got me there! All I've had a chance to do so far is fit a genuine Toyota fuel filter, it's helped a little bit but still every now and then it almost feels like it's barely got enough power to get up a hill, but other times it seems fine.

No I haven't checked the breather, didn't realise that was a thing. Where is it located?
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IRLGW

Well-Known Member
Dec 2, 2011
1,017
258
83
It runs from the tank to your filler cap but if the filler cap is faulty then it doesnt breath properly, (there is probably a thread somewhere). If after driving for an hour or so, or when the tank is low you get that whoosing sound when you open the cap, then its blocked and the whoosing sound is the air running into the tank which is under partial vacuum. the fuel cap is servicable I believe and the there is a diaphram under a spring I think. you could try driving with the filler cap loose but just make sure the tanks not too full.
 
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