1hz idle speed and how much should it vary ? (1 Viewer)

[sunrk]

My 80's 1hz idle speed is very variable. It seems to range anywhere between 600 and 800 rpm depending on it's 'mood', ambient temp of the motor, etc.. Is that normal? The idle speed setting screw on the injector pump isn't loose.

The 1hz is old (685 k km's now). Injector pump and injectors were renewed with reco parts at about 510 k km about 10 yr ago.

 

[Dusten]

My 80's 1hz idle speed is very variable. It seems to range anywhere between 600 and 800 rpm depending on it's 'mood', ambient temp of the motor, etc.. Is that normal? The idle speed setting screw on the injector pump isn't loose.

The 1hz is old (685 k km's now). Injector pump and injectors were renewed with reco parts at about 510 k km about 10 yr ago.

Did you not find the answer last time you asked?

Varying idle speed with 1hz motor - what can cause it?

Is anyone aware of what can cause the idle speed of a 1hz to vary away from the 'screw setting' on the injector pump? I've got mine wound up a little (I set it to 700) because of the rough idling issue, but sometimes it'll idle up to 800 rpm. I haven't get done anything with injectors (got a...

forum.ih8mud.com

 

[sunrk]

No - I don't know where the mysterious 'dash pot' is that people talk about. Never taken an injector pump apart.

Just seeing the power output appears to be lower that I'm used to and fuel usage is higher than I was getting in the past. I know it's a very aged motor. I'm not in possession of a compression tester or leak-down tester kit(s).

How much difference or improvement in operation would a brand new head be likely to realise? I don't have the ability to rebuild the whole motor.

 

[Dusten]

If you have 600+km in the engine swapping heads is a band aid

 

[mudgudgeon]

I agree, putting a brand new head on a motor with that many miles would not be good value for money.

It's probably gonna be lipstick on a pig.

 

[sunrk]

Thinking that too - but it's def an option. I'm going to investigate crate motors soon once I get the funds I need. At 30 yrs old, a replacement motor will now definitely outlast me (as I'm 53) and the usable life of the vehicle. Unless the body gets too rusted or damaged, I've got no reason to stop using it.