1HDT injector pump adjustment advice

[PTW]

Hi there

My recently purchased vehicle only gets up to 400degC EGT on a long 3rd gear hill. After doing a search on here I am still a bit confused as to turn the adjustment screw which way. I read conflicting theories on running leaner v' more fuel. So should I be adjusting clockwise for more fuel to get peak effecieny of around 550-600 EGT ? My guess is yes, but value your input.

ps I just had the injectors replaced yesterday and it is hot idling a bit lower too, for what it's worth.

Cheers Paul

[hdj105]

You don't say where you are measuring EGT's, but 400C peak after full throttle on a long uphill run leaves room for more fuel.

Turning the main fuel screw clockwise will increase the fuel and thus the heat (and power). Unless you have increased the boost and the aneroid is now going into "overboost" (protection) mode where it will actually decrease the injected fuel.

Don't need to worry about running the diesel lean, everytime you take your foot off the throttle it runs lean by itself.

[PTW]

The pyro is into the exhaust manifold.

After having the injectors changed yesterday my exhaust pipe has a lot more soot in it. Boost has not been touched. I'll try 1/8th turn increments CW then and see what happens. Thanks for your help mate

edit - could it be possible that it is now running too rich with the new injectors and would the EGT's lower because of that. Excuse my ignorance of diesels but I'm just trying to learn.

Cheers Paul

[hdj105]

edit - could it be possible that it is now running too rich with the new injectors and would the EGT's lower because of that. Excuse my ignorance of diesels but I'm just trying to learn.

400c is quite cool if the probe is mounted pre-turbo. How does the vehicle perform otherwise? Is it intercooled?

If it were running rich the temps would be higher (you need to stop thinking petrol engine).

Diesel = more fuel (rich) = more heat

[PTW]

edit - could it be possible that it is now running too rich with the new injectors and would the EGT's lower because of that. Excuse my ignorance of diesels but I'm just trying to learn.

400c is quite cool if the probe is mounted pre-turbo. How does the vehicle perform otherwise? Is it intercooled?

If it were running rich the temps would be higher (you need to stop thinking petrol engine).

Diesel = rich = more fuel = more heat

It has a DTS intercooler on it and yes to clarify the probe is pre turbo. I can't really guage how it feels as I don't have anything to compare it too but I "feel" it is sluggish for the torque it should have. I guess the key is to tune it to the EGT which I have been told would be 550-600 under an uphill loaded condition. I shall stop thinking petrol too and go and give it a tune this arvo.

Thanks very much for your help too.

[PTW]

Well I had a few goes at trying to adjust it. From a benchmark peak EGT 325 on the first run I only managed to get it to 425 max before I couldn't reduce the idle down any further and even that was around 800-900 rpm. This was wound CW 3/4 from the initial setting. Put it back a bit so at least the idle has dropped to around 700rpm now. Perhaps as you said earlier that boost controller is coming into play and reducing it in compensation. Will try and find a good tuner and put it on the dyno.

[hdj105]

Well I had a few goes at trying to adjust it. From a benchmark peak EGT 325 on the first run I only managed to get it to 425 max before I couldn't reduce the idle down any further and even that was around 800-900 rpm. This was wound CW 3/4 from the initial setting. Put it back a bit so at least the idle has dropped to around 700rpm now. Perhaps as you said earlier that boost controller is coming into play and reducing it in compensation. Will try and find a good tuner and put it on the dyno.

How long is your long run, i.e. how long can you keep your foot flat and what rpm is the engine at?

What boost is you peaking at, and where are you measuring it from?

3/4 of a turn should have seen more of a result. And why can you not adjust your idle down - have you run out of thread?

[PTW]

Well I had a few goes at trying to adjust it. From a benchmark peak EGT 325 on the first run I only managed to get it to 425 max before I couldn't reduce the idle down any further and even that was around 800-900 rpm. This was wound CW 3/4 from the initial setting. Put it back a bit so at least the idle has dropped to around 700rpm now. Perhaps as you said earlier that boost controller is coming into play and reducing it in compensation. Will try and find a good tuner and put it on the dyno.

How long is your long run, i.e. how long can you keep your foot flat and what rpm is the engine at?

What boost is you peaking at, and where are you measuring it from?

3/4 of a turn should have seen more of a result. And why can you not adjust your idle down - have you run out of thread?

About a k long 3rd gear gets to 3200 max, 13 deg incline. It's peaking at 10-11psi around 2k from memory. Boost gauge is teed into the compensator on the pump and post intercooler.

As I turn the screw up the idle also rises. It got to the point where I had both those idle screws not touching and could not get it lower than 1000rpm.

Perhaps the boost compensator is coming into effect and retarding fuel ??

I have booked in to Northside4x4 next week anyway. They have a Dyno and focus mainly on 4x4 but I have heard some very good reports from guys in the WRX Club that I'm in regarding there tuning. He mentioned that they don't normally touch that adjustment screw and that there is other adjustments that they make to the pump or something. I will have more of an idea when I see them next week anyway.

[hdj105]

[
About a k long 3rd gear gets to 3200 max, 13 deg incline. It's peaking at 10-11psi around 2k from memory. Boost gauge is teed into the compensator on the pump and post intercooler.

As I turn the screw up the idle also rises. It got to the point where I had both those idle screws not touching and could not get it lower than 1000rpm.

Perhaps the boost compensator is coming into effect and retarding fuel ??

Test hill sounds ideal.

Boost sense also ideal, so gauge is reading the same as the compensator and what the engine is receiving. My intercooled 1HD-T used to peak at 11.5psi.

The compensator should not be pulling fuel out at that boost pressure so I doubt that is your issue.

Sounds like you may have something strange going on with your pump

[PTW]

Actually measured it on the way home 2km long. I used it when I was finetuning my STi as well. The incline is good to load up turbos.

I bought a Haynes manual today. It doesn't mention that adjustment screw at all only the max rpm, idle and a/c idle It does however talk about rotating the pump to adjust timing or plunger stroke so perhaps that is out. Fingers crossed it is something simple. Otherwise yes perhaps the pump is sad Will post up anyway what he finds

[PTW]

Well I had it on the dyno this morning and it runs lean up top, hence the low EGT. Suspect boost advance in the pump. So I'll get a new / reco pump when I get back again. I also have to block off the the area around the intercooler as the air is passing thru an inch gap at the back and around the sides. A rubber shroud definately and possibly deflector plate at the front should help things there.