1HD-T idle problem - need help! (1 Viewer)

[David60series]

Something is expanding and losing pressure. IP do this but normally after they are well warmed and usually at higher speeds. It is usually the first sign of a worn out pump.
What happens if you bump the idling up 100rpm permanently?

The few strange things so far:

This problem surfaced on the old pump. Went away with new pump and now back.

Cracking any injector Union evens up the idle.

No other symptoms other than in my opinion it's a bit gutless off the mark.

Also the old scored injectors tested ok on their primary stage still.

Long drive on short boat ramp is tempting.

 

[David60series]

Team,

The 80 has been parked up for some time. I gave it a run at Christmas and towed a trailer to our property about a 250km trip.

The idle shake is still there when hot. Sometimes worse than others.

I've noticed too that when shutting the engine down it had 'run on' with a big shake a few times.

I also reckon it's down in power when off boost too.

Although the cranking compression was very good (470-480psi) I'm just wondering if there is still a valve related problem or compression leak issue. Some valves were found to be out when pump was refitted, with no.1 inlet from memory almost riding. Tolerances were corrected.

Can boost hide a compression/valve related problem? I reckon it's slow to build boost.

I will try and run my AFR meter thus weekend. Previous to the pump rebuild my AFRs were heading south badly at 3000rpm down to mid 17s. I had assumed it to be pump related. If the readings are still strange this might support my theory.

I guess next is valve clearance check then leak down test.

 

[roscoFJ73]

Has the fuel cut off solenoid been removed and tested?

 

[David60series]

Pretty sure fuel cut was replaced. I will check. No - haven't tested it.

 

[roscoFJ73]

Pretty sure fuel cut was replaced. I will check. No - haven't tested it.

I was wondering if its fully open. I also remembering pulling one out and it was coated in slime, but if yours has been rebuilt, this shouldn't be a problem.

 

[mudgudgeon]

I guess next is valve clearance check then leak down test.

Another thing you can do is add a little oil to the cylinder before repeating the leak down test. If it improves leak down result, rings are suspect. If leak down result doesn't change, it points to leaking valves, or head gasket.

If compression is low in two adjacent cylinders, eg, 3&4 low, you may have a head gasket leak between two cylinders. This could possibly affect compression at idle without combustion gas leaking through to water jackets.

 

[David60series]

I don't think it's as straight forward as a head gasket due to such good cranking compression results (2 @ 470 and 4 @ 480 psi). It would be nice if it was though!

 

[mudgudgeon]

What's the compression in the other cylinders?
Leak down test might give a clue, or not.

Agree, it may have nothing to do with head gasket at all, but sounds like you're running out of possibilities, and if you have a tester, costs nothing to do some testing.

I reckon it's either something simple outside the square, or IP related

 

[David60series]

From memory cylinder 1&2 were 470 and 4-6 480psi.

The pump and injectors are under warranty and I've spoken a few times to the shop who are happy to build another IP and injectors to try but I'd like to rule out anything else if possible first.

 

[roscoFJ73]

Bench testing the pump and injectors allows the shop to measure the amount of fuel sent to each cylinder at various speeds. I would have gone there long ago, if only to rule those items out.
For those who don't know, the injector pump is connected to an electric motor. The motor can be spun at speeds replicating engine speed. The fuel delivered to each injector can be measured by volume or pressure.

 

[remy]

Try replace the governor spring, intermediate spring and seat in the pump. You can do it whilst in the car.

 

[mudgudgeon]

Try replace the governor spring, intermediate spring and seat in the pump. You can do it whilst in the car.

Yeah, it's doable, but definitely a job for the shop to do while under warranty

 

[roscoFJ73]

The governor spring has been replaced.
I'm starting to think there is an injector not opening correctly at low rpm, maybe a bad spring or not shimmed correctly. The second video of the exhaust seem to have slight rhythmic miss

 

[David60series]

The governor spring has been replaced.
I'm starting to think there is an injector not opening correctly at low rpm, maybe a bad spring or not shimmed correctly. The second video of the exhaust seem to have slight rhythmic miss

The only issue with this theory is that the problem was the same with the previous injectors and pump. It went away for a few thousand km then came back.

Yes it's def a rhythmic miss.

Yep the governor spring has def been replaced.

 

[sunrk]

Just to prove I do things properly here are some of my parts after arriving and my work.

Did you buy a brand new genuine front axle housing (the large Toyota box)? Out of interest what was the part-number of it and what was the source (Toyota, Amayama, Partsouq, etc.) and cost?

I am having a rough idle issue with my 1hz that's getting close to 634 k km's (motor's original to the vehicle). I'm fairly sure it's not air getting into the fuel system, and I'm suspecting something going on with the injector pump (or injectors), or perhaps a head issue. I know that I could do a head replacement myself if I needed to as new 1hz heads are still made by Toyota (wow).

 

[David60series]

Did you buy a brand new genuine front axle housing (the large Toyota box)? Out of interest what was the part-number of it and what was the source (Toyota, Amayama, Partsouq, etc.) and cost?

I am having a rough idle issue with my 1hz that's getting close to 634 k km's (motor's original to the vehicle). I'm fairly sure it's not air getting into the fuel system, and I'm suspecting something going on with the injector pump (or injectors), or perhaps a head issue. I know that I could do a head replacement myself if I needed to as new 1hz heads are still made by Toyota (wow).

I sourced the genuine axle housing via Mike Carney Toyota in Townsville who tracked one down at a Sydney dealer. There were not many left. It was around $1600 from memory and I used the later ABS model part number as I think the early one was obsolete. The only change was a bracket for ABS sensor.

I have all the receipts filed, but not handy as I'm away at work. It was over 5 years ago so I can't confirm they are still available in Aus.

 

[sunrk]

Ta, toyodiy reports this list of numbers for my config of 80 (3/92 hzj80 aus edition):

43110 HOUSING ASSY, FRONT AXLE
43110-60270
1 $2,217.83
43110-60290 W(FRONT DIFFERENTIAL LOCK) (12/1990 - 07/1992) 1 $2,217.83
43110-60370 (08/1992 - 12/1998) 1 $2,104.67
43110-60390 W(FULL FLOATING AXLE & FRONT DIFFERENTIAL LOCK)

Obviously the prices shown are irrelevant.

 

[David60series]

The only issue with this theory is that the problem was the same with the previous injectors and pump. It went away for a few thousand km then came back.

Yes it's def a rhythmic miss.

Yep the governor spring has def been replaced.

Team,

I started the 80 again on the weekend and drove it with AFR gauge hooked up. I had not done this since the injection was replaced.

It is still showing 24-22 at full load and boost (11psi) but starts heading south to the 20:1s in the 2500 rpm range and into the 18s close to 3000rpm.

I understand that this is not normal if boost is stable and brings me back to wondering about a valve related problem.

When I get the spare cash and time off work I'll take it for a leak down test.

I've sent off an oil test of the engine oil to see if that provides any clues.

Any thoughts?

 

[samuel payet]

Sorry to revive and old thread... but did you ever find out what this was? I have the exact same symptoms in my HDJ80, rough idle and gets worse when hot, a short burst of the throttle will help for a couple of seconds but then it gets rough again. It's driving me nuts!

 

[David60series]

Sorry to revive and old thread... but did you ever find out what this was? I have the exact same symptoms in my HDJ80, rough idle and gets worse when hot, a short burst of the throttle will help for a couple of seconds but then it gets rough again. It's driving me nuts!

You might be in luck due to my bad luck.

I have the 80 in the workshop this week. It has had a leak down test, another compression test and valves checked. All OK.

Spraying Esther into the inlet whilst it's idling rough resolves the problem in the same way applying throttle does so we can almost certainly say it's injection related as the motor is good.

As such, pump and injectors will be coming off for testing.