Fuel Adjustment Screw

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DelicaMark
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Fuel Adjustment Screw

Post by DelicaMark » Thu Dec 20, 2007 11:21 pm

Kind of hard to get a good shot of this but here we go.
Here is the injector pump. The screw is on the back left when looking from the front. It is about 2-3" down from the top of the pump. Look for the brass coloured protective cap...see next picture.
Injector Pump.jpg
Injector Pump.jpg (52.05 KiB) Viewed 2475 times
Protective cap...that I didn't bother putting back on. It comes off quite easily. I think I used a very small flat head screw driver and tapped the end with another screw driver. I really just tapped it and it started to move.
cap.jpg
cap.jpg (71.07 KiB) Viewed 2474 times
Here is a shot of the lock nut and screw without the cap on of course.
Adjustment Screw.jpg
Adjustment Screw.jpg (44.07 KiB) Viewed 2475 times

I used a deep 13mm socket to loosen the lock nut and then a stubby quickpic to adjust the screw. You can see the blue felt that I marked the screw with so I could put it back if required.

I also found it easier to work back there if I removed the two connectors going to the pump and moved the automatic transmission kick down cable out of the way.

Hope this helps.

-Mark

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CVI
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Re: Fuel Adjustment Screw

Post by CVI » Sat Dec 29, 2007 11:27 pm

Hi! just a word of caution on that screw. That's the full load adjustment and is factory preset to deliver the right amount of fuel at certain load conditions. The reason it's sealed with the cap is ....well ...they don't want us to touch it. There are a lot of shims inside the pump that eventually wears out thru time, fuel quality and kms run. When these shims wear, then another part called the plunger and barrel starts to deliver more fuel than necessary. These can be preset only with a calibration machine. So be careful, you can adjust it turning clockwise for more fuel and anticlock for less but only in very small increments. Good luck.
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thelazybrownfox

Re: Fuel Adjustment Screw

Post by thelazybrownfox » Sun Dec 30, 2007 7:20 am

Hey Mark
I assume you have adjusted this (mixture) screw. Any result yet? What was the mileage on your Delica? Did you suspect a problem before you adjusted this screw?

Thanks
Wayne

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Re: Fuel Adjustment Screw

Post by PolyTek » Sun Dec 30, 2007 12:17 pm

This thread begs the question, at what point should we consider replacing (or servicing) the injector pump so that it continues to operate to spec?
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DelicaMark
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Re: Fuel Adjustment Screw

Post by DelicaMark » Sun Dec 30, 2007 6:41 pm

thelazybrownfox wrote:I assume you have adjusted this (mixture) screw. Any result yet? What was the mileage on your Delica? Did you suspect a problem before you adjusted this screw?
I was trying to reduce the amount of smoke that the van was producing. I would say that adjusting the screw did not do much for reducing the smoke. If anything it was an incremental improvement for smoke reducton along with the EGR valve being disabled. I was going off some of the UK posts about if you blank the EGR valve then you should turn down the fuel by adjusting this screw. I getting the injection pump timing checked out this week and hopefully that will shed some light onto things.

-Mark

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DelicaMark
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Re: Fuel Adjustment Screw - Follow Up

Post by DelicaMark » Wed Jan 23, 2008 11:01 am

A follow up to this post that is required and for that matter a lot of other posts on this and other Delica sites.

I adjusted this full load screw thinking that it was going to help reduce the amount of black smoke that my van was outputting. I did this based on piecing together a few posts from the UK site. The posts totally made sense to me and that is why I decided to monkey around with the adjustment screw.

Now that I have actually had my van's injection system properly tuned by a Mitsu mechanic I realize that this is not a good thing to have done and that it is totally NOT REQUIRED if your van is properly tuned.

I have put the adjustment screw back to the factory setting and would highly recommend not messing around with it because it really didn't solve any problems that I was having and likely will not solve any problems that anyone else is having.

I hope that you all would agree that it is the responsiblity of the users of this site to make sure that our posts are as complete as possible so we don't end up misleading any of our fellow Delica owners. I realize that it will not be possible to always have a resolution but it would be a good best practice for the person that starts a post to try and close up the post.

Sorry for yet another wordy post but I thought it was important to say.

-Mark

thelazybrownfox

Re: Fuel Adjustment Screw

Post by thelazybrownfox » Wed Jan 23, 2008 1:54 pm

Hey Mark

You are spot on. Thanks for keeping your post updated.

Has you fuel mileage increased since the tune? I'll be curious to hear your oppinion of the cost of the tune compared to the black smoke (decrease) and fuel mileage increase. Ant idea what was actually adjusted?

Thanks
Wayne

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DelicaMark
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Re: Fuel Adjustment Screw

Post by DelicaMark » Wed Jan 23, 2008 2:30 pm

Hey Wayne check out this post http://www.delica.ca/forum/hard-startin ... -1850.html for the results of the tune.

I haven't had a full tank of fuel through since the tune so I am not sure on the fuel economy yet. I think it should get better but who knows.

thelazybrownfox

Re: Fuel Adjustment Screw

Post by thelazybrownfox » Wed Jan 23, 2008 3:08 pm

Thanks again Mark

I read that post not 30 sec ago. Great news eh. I'll keep that timing in mind as I go further in my t belt change.
Wayne

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