Primer fuel Hose Sizes and power under Load

[PowWowWow]

Good evening all,

94 Turbod HZJ80R 80 Series

Just did new Injectors Torqued with Copper grease seated no issues. Fuel lines clamped back down no issues no apparent leaks. Followed Roscos advice on bleeding via the glow plug holes this was very effective at keeping the fuel lines sealed.

Primer pump was replaced as old one was leaking, hose size on original took 12mm hose new one only takes 8mm.

As a lot of gear is upgraded to turn the HZ into a HD I’m wondering if the change from factory size is affecting power under load. Do I need to use a 1HDT Primer that take 12mm fuel hoses as this is the size found at the INJPMP and at the feed from the Fuel tanks.

My cruiser is fine at the low end but anything over 75kmh it is struggling with up hill and it feels as though the pump is starved of fuel.

This could be an old topic just trying to figure this out before spending more money

Regard Lew.

 

[PowWowWow]

Primer installed and plumes of diesel just more photo evidence for the friendly folk on here. Lines were bled until stead plumes from each cylinder.

 

[mudgudgeon]

Early 1hd-t had 10mm feed lines, Toyota upgraded this to 12mm due to fuel starvation issues.

It's probably better to have the 12mm lines

But, if the hard lines are original 1HZ lines, having 12mm hose at the primer/ filter isn't likely to matter.

My cruiser is fine at the low end but anything over 75kmh it is struggling with up hill and it feels as though the pump is starved of fuel.

Struggling how? Just sluggish? Or do you feel a stumble? Does it blow any white smoke when you feel it's struggling?

Do you feel it struggles under load at other times? I had a fuel issue with mine that showed up under load or hard acceleration at 2000-2500 rpm.

Have you used a clear hose to check for air bubbles in the fuel?

Have you checked the timing?
Does you IP have a boost compensator installed?
What have you done to tune it?

 

[PowWowWow]

The cruiser is stumbling. So it’s been sitting for weeks at a time. Then bled and driven each weekend for multiple trips over Saturday and Sunday no loss of power. Come Monday doesn’t fire up. I had a leaky primer which took the larger fuel lines.

I suspected that if it was leaking fuel it must be sucking air. Swapped it out but now it takes the smaller lines and now I have a loss of power under load. Last 2 weekends with the old primer and larger lines no loss of power but air was getting back into the system. Now with new smaller lines I’m getting less power uphill, could be unrelated, But it’s the only thing that’s changed between the weeks.

 

[PowWowWow]

I’m very much in the early stages of giving this cruiser love too still learning as much as I can. I haven’t tuned the injector. However I’ve installed gauges and am running 10 pds of boost

 

[PowWowWow]

I believe I’ve sorted the air in the lines issue but only this week will tell when I go to start it and if it turns over but if it’s still sluggish, I’ll try a new primer and larger lines. Like original.

 

[PowWowWow]

I believe I’ve sorted the air in the lines issue but only this week will tell when I go to start it and if it turns over but if it’s still sluggish, I’ll try a new primer and larg

Early 1hd-t had 10mm feed lines, Toyota upgraded this to 12mm due to fuel starvation issues.

It's probably better to have the 12mm lines

But, if the hard lines are original 1HZ lines, having 12mm hose at the primer/ filter isn't likely to matter.


Struggling how? Just sluggish? Or do you feel a stumble? Does it blow any white smoke when you feel it's struggling?

Do you feel it struggles under load at other times? I had a fuel issue with mine that showed up under load or hard acceleration at 2000-2500 rpm.

Have you used a clear hose to check for air bubbles in the fuel?

Have you checked the timing?
Does you IP have a boost compensator installed?
What have you done to tune it?

When you say hard lines are you referring to the lines between the injectors and injector pump or fuel lines from fuel tank.

 

[PowWowWow]

Apologies for the sporadic replies, IP does not have a boost compensator and it hasn’t been timed by me, certainly don’t think the previous owner timed it it would have been timed when the turbo was installed many years ago.

 

[mudgudgeon]

Hard lines from the tank to primer were upgraded to 12mm

 

[mudgudgeon]

it would have been timed when the turbo was installed many years ago

I wouldn't assume it was ever timed or tuned right.
Maybe it was, but they often aren't.
Lots of shops would just fit a turbo and turn up the fuel, wham bam, more power ma'am! Happy customer until things go Boom! 6 months, a year, two years down the track.

A boost compensator gives you a lot more adjustability when tuning. Ideally, you wouldn't turbo a 1hz without adding a boost compensator.

With a boost compensator you can add more fuel overall, but have better/finer control over fueling throughout the RPM range so you aren't dumping excessive fuel in at low RPM.
Excess fuel produces excess heat in the precombustion chambers, and cylinders, which is what will kill a turboed 1HZ.

 

[PowWowWow]

Ahhh okay yeah so lines from tank are 12 and IP takes 12 and old Primer took t12 but now between the 2 it’s hose size has had to be reduced for the new primer. I’m not an expert by any means but I’m assuming pressurised flow of fuel in the smaller hose means less fuel overall is being delivered to the pump under load.

I’ll call a leading injector place here in country Victoria and see what they’ve gotta say might need to be tuned and rebuilt properly.

 

[PowWowWow]

That’s were I’m not sure it’s a DTS Turbo that was fitted like 20 years ago, the EGTs are high for my liking but the tuning/ turbo still has receipts from when it was installed so I feel as tho they mustn’t have done too bad a job of it just hasn’t been hammered by previous owners. I’m not too sure but I think those previous mentioned points are in order

I wouldn't assume it was ever timed or tuned right.
Maybe it was, but they often aren't.
Lots of shops would just fit a turbo and turn up the fuel, wham bam, more power ma'am! Happy customer until things go Boom! 6 months, a year, two years down the track.

A boost compensator gives you a lot more adjustability when tuning. Ideally, you wouldn't turbo a 1hz without adding a boost compensator.

With a boost compensator you can add more fuel overall, but have better/finer control over fueling throughout the RPM range so you aren't dumping excessive fuel in at low RPM.
Excess fuel produces excess heat in the precombustion chambers, and cylinders, which is what will kill a turboed 1HZ.

 

[mudgudgeon]

Any reduction in hose or fitting diameter is a potential restriction to flow.
A short change through a fitting is not as bad as a long piece of hose.

A turbo fitted by DTS 20 years ago is going to be super old tech, and will be a turbo built for a petrol engine.
DTS and others typically ran low boost, like 7-9psi range with the idea that too much boost kills these engines.
They were typically tuned rich to provide hot gas to drive a poorly matched turbo. This also means high EGT.

Higher boost is your friend, hot combustion temps definitely are not. Boost helps keep EGTs low.

What EGTs and boost psi are you seeing?

You want to know what your peak temperature is, so high load, wide open throttle (from close to idle, through to 4000-ish rpm), climbing a steep hill in 4th gear, or D if auto.

EGT readings should be taken before turbo, not after.


Personally, I would be looking to run boost in the 15-20psi range,
BUT the turbo needs to be working within its efficient range. A poorly matched turbo running at high boost can heat the intake air excessively which is a whole different problem.

Any turbo DTS used will not be suitable for 15psi boost. You'll be limited to low boost and likely fighting high EGT temps.

If you're a reader, there's a lot of good tech on this stuff in the Diesel Tech / 24 volts - https://forum.ih8mud.com/forums/diesel-tech-24-volts.24/ part of the forum

 

[PowWowWow]

Spoke to Sloane Diesel Services,

Bought brand new injectors off of them that I installed recently.

They’ve said if Hoses are the only thing I’ve changed and the Primer, they suggested swapping it out for a genuine 1HDT primer that can support the correct size hoses.

Also something I didn’t mention is that the 1HZ Primer that I installed was not an OEM Primer, from their experience they said non OEM Primers have sucked air each time they’ve come into their workshop noting that the small amount of air that these are pulling could also be reducing power output under load.

I’ll be picking up a genuine Toyota 1HDT Primer and fitting it with the right hoses, will bleed again via the glow plugs and if it persists sadly it’s the Injector Pump.

Toying with the idea of detuning it and removing turbo in the future as I don’t have the funds to upgrade the turbo to a propper built system currently and need the longevity versus the power.

Any inputs on detuning?

I will read that linked forum though as I enjoy the reading!

 

[PowWowWow]

Any reduction in hose or fitting diameter is a potential restriction to flow.
A short change through a fitting is not as bad as a long piece of hose.

A turbo fitted by DTS 20 years ago is going to be super old tech, and will be a turbo built for a petrol engine.
DTS and others typically ran low boost, like 7-9psi range with the idea that too much boost kills these engines.
They were typically tuned rich to provide hot gas to drive a poorly matched turbo. This also means high EGT.

Higher boost is your friend, hot combustion temps definitely are not. Boost helps keep EGTs low.

What EGTs and boost psi are you seeing?

You want to know what your peak temperature is, so high load, wide open throttle (from close to idle, through to 4000-ish rpm), climbing a steep hill in 4th gear, or D if auto.

EGT readings should be taken before turbo, not after.


Personally, I would be looking to run boost in the 15-20psi range,
BUT the turbo needs to be working within its efficient range. A poorly matched turbo running at high boost can heat the intake air excessively which is a whole different problem.

Any turbo DTS used will not be suitable for 15psi boost. You'll be limited to low boost and likely fighting high EGT temps.

If you're a reader, there's a lot of good tech on this stuff in the Diesel Tech / 24 volts - https://forum.ih8mud.com/forums/diesel-tech-24-volts.24/ part of the forum

Uphill on the Western Fwy in some of the longer inclines I can do 90kmh at about 470 EGT and this is maxing out the boost at 10 psi. I try not to take it past 500 due to its age and age of the turbo parts etc.

Really steep hills don’t even allow me to take it in 4th, near my joint I have to take most in third otherwise EGTs would be way to high, Id blow my engine up each day if I tried to take some of the hills in 4th daily. But I do regularly see Cruisers drive past my place and most have to do the same so I’d count that as normal driving behavior. Speed limit is 80 but most of the cruisers have to take it 60 with high RPMs in third.

And yeah I never take it past 500, and Boost is maxed out at 10psi it never goes past this.

 

[mudgudgeon]

I try not to take it past 500 due to its age and age of the turbo parts etc.

If you keep your foot planted, will it keep going past 500⁰?
Peak EGT under load gives an indication of how it is tuned. If you lift your foot to stay below 500, you're not seeing the peak and it's not really showing its true colours in regards to tuning

Also, you didn't confirm if the probe for your EGT gauge is before the turbo? Ie. Is it in the exhaust manifold before the turbo, or in the exhaust pipe after the turbo.
Temperature can fluxtuate by 100-200- 300⁰ as gases go through the turbo. After turbo reading of 500⁰ could be 700⁰ before the turbo. There's no way to be sure as many things affect his much the temperature has dropped..

 

[mudgudgeon]

Also something I didn’t mention is that the 1HZ Primer that I installed was not an OEM Primer, from their experience they said non OEM Primers have sucked air each time they’ve come into their workshop noting that the small amount of air that these are pulling could also be reducing power output under load.

I’ll be picking up a genuine Toyota 1HDT Primer and fitting it with the right hoses, will bleed again via the glow plugs and if it persists sadly it’s the Injector Pump.

A small amount of air getting sucked into the fuel can cause havoc with these. Mainly as it changes injection timing. Air bubbles in injector lines compress (fuel does not), which means injectors don't get enough pressure to pop openn on time. This effectively retards the timing, leading to a misfire or poor combustion or both.
If this is happening, you'll possibly feek the engine stumble, or see whiteish smoke out the back.
Temporarily installing a clear puece of pvc tube between the fuel filter and the injection pump can make air bubbles visible.


If you've just changed the filter, or replaced a hose, bleeding injectors shouldn't be necessary. The hand primer will fill the filter and hoses. The infection pump will stay full of fuel. If the engine starts up right away, any bubbles will work there way out in a few minutes of running

 

[PowWowWow]

First off just want to say I appreciate all the communication back and fourth MG, you’re a wealth of information. Probe is located in the dump pipe so after the turbo.

This position is confusing to me as I read a post about the placement of the probe probably 10 months ago regarding putting it pre turbo as you have suggested. I ran this past the mechanic/ engine builder who said it must go in this position. He often works on V8s, he’s built multiple 79 series and is a reccomended head gasket repairer from Hoppers Heads another well reccomended head gasket shop in Melbourne, has also built drag cars so I don’t understand this decision based on his clear background in engine work????

Again Im saying this was confusing for me because I understand why this placement would be better and that it does make sense but he insisted on this location so it ended up there.

Post this about 8 months ago I’ve done everything else but is alarming if my real engine temp could be getting so much higher.

If I plant my foot Highest I’ve seen it before I’d 530 and I’ve backed off as it was due to a lapse of monitoring of the gauge under load.

 

[PowWowWow]

If you keep your foot planted, will it keep going past 500⁰?
Peak EGT under load gives an indication of how it is tuned. If you lift your foot to stay below 500, you're not seeing the peak and it's not really showing its true colours in regards to tuning

Also, you didn't confirm if the probe for your EGT gauge is before the turbo? Ie. Is it in the exhaust manifold before the turbo, or in the exhaust pipe after the turbo.
Temperature can fluxtuate by 100-200- 300⁰ as gases go through the turbo. After turbo reading of 500⁰ could be 700⁰ before the turbo. There's no way to be sure as many things affect his much the temperature has dropped..

MG so would an ideal placement be at the exhaust manifold, I remember reading previously that the 6th cylinder exit was a good placement?