Injector heat shield washers

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Dongshoreman
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Injector heat shield washers

Postby Dongshoreman » Thu May 30, 2019 5:39 pm

Hello everyone,
I have been working on troubleshooting my fuel system (see my other post "Losing Prime), and today I removed my injectors to inspect them. When I took them off I also removed the copper washers, but I did not see the stainless steel heat shield washers. To be honest I was unaware of their existence while I was taking it apart, but after reading a few posts here it looks like they are extremely important. Should they come out really easy with the injectors? If they are indeed missing, could this contribute to my loss of prime?
1983 Diesel Shortbed

2sk8
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Re: Injector heat shield washers

Postby 2sk8 » Thu May 30, 2019 7:47 pm

No, the heat shields will not contribute to your loss of prime. They keep the heat away from the injectors. If you don't have heat shields, you need to install them

I have a couple of sets of brand new heat shields if you want one set.

About you loss of prime:

Looks like you have tried many things to figure this out. You already check the hand priming pump, and fuel lines and so on, right?

So.

I believe you may be losing prime from the injection pump itself. There is MANY places where you can have air leaking into the pump.

How does the injection pump looks like? Is there any fuel leaks?

You may have a leak or several leaks in the Inlet or out line. They need to be torque to 14-18 ft-lb.

Also you may have a leak on the shaft seal. Or the pump seals,

Keep in mind that if you injection pump is original then it's over 30 years old...

Here is a torque and parts list of the VE pump so you have an idea of what I'm talking about.

Please check picture attached
Attachments
VE Pump Torque and Parts.jpg

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Halden
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Re: Injector heat shield washers

Postby Halden » Fri May 31, 2019 6:28 am

2sk8 wrote:I believe you may be losing prime from the injection pump itself. There is MANY places where you can have air leaking into the pump.



I'm not saying it's impossible, but I would think that is highly unlikely. But perhaps we should entertain this idea as this has been going on a long time! With the injection pump being mounted so low and everything being air tight before that it would probably pull fuel through everything as it leaked and no air would be getting in. Unless he had a very large leak which I think would be quite visible.
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Re: Injector heat shield washers

Postby VEGGIE NATE » Fri May 31, 2019 8:43 pm

I think the heat shield you are referring to is actually shaped like a cup that the tip of the injectors sit in. They are hard to remove and if I was you I wouldn’t mess with them.
1986 P'UP LWB,2WD,N/A,5-SPEED,3.42,WVO TWO-TANK

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Re: Injector heat shield washers

Postby Dongshoreman » Sun Jun 02, 2019 10:38 am

I was kind of wondering if this was the case. They didn't come out when I pulled the injectors, but I think they are probably inside. I will double check before I put it all back together.
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Paul
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Re: Injector heat shield washers

Postby Paul » Mon Jun 03, 2019 12:31 am

Not sure which washers you are discussing. Here is a link to a post showing that there are three parts in the hole under the injector.

Way down is a cup that normally is not removed. Next is a thin wavy washer and finally at the top is a copper seal washer.

viewtopic.php?f=1&t=2577&start=15

And, here is a scan from the service manual showing how the wavy washer is to be installed.

Installation Info & Torque snapshot email  .jpg


Paul
'84 P'UP 2 wd diesel, 5 spd with 0.78 fifth gear and differential back to 3.73.

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Re: Injector heat shield washers

Postby Dongshoreman » Mon Jun 03, 2019 9:42 pm

Paul,
Thanks for your input. Once those wavy heat shield washers are installed do they come back out easily? I replaced the copper washers and before I reinstalled the injectors I shined my flashlight inside and I could see something that looked like a washer of some sort, but I couldn't tell if it was just part of that cup that was discussed earlier. All four cylinders looked the same. If the heat shield washers are actually in there they are really tight, is that normal? If not, I may be missing all four. I'm assuming that could do some damage in the long run, am I right?
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Re: Injector heat shield washers

Postby Paul » Tue Jun 04, 2019 12:35 am

Dongshoreman wrote:Paul,
Thanks for your input. Once those wavy heat shield washers are installed do they come back out easily? I replaced the copper washers and before I reinstalled the injectors I shined my flashlight inside and I could see something that looked like a washer of some sort, but I couldn't tell if it was just part of that cup that was discussed earlier. All four cylinders looked the same. If the heat shield washers are actually in there they are really tight, is that normal? If not, I may be missing all four. I'm assuming that could do some damage in the long run, am I right?


Yes, do not run the engine without the wavy washers as they protect the nozzle tips from the combustion flame.

The wavy washers should retain some of their wavy appearance down in the hole and they should be a bit shiny too. The cup is not shiny. And they usually do come out fairly easily. Only problem is to get a hold of them. They are not magnetic.

Jerry Lemond has a tip for removing the wavy washers: He says to use an 8mm bolt and thread it into the washer and then pull it out. I have used this and it works. Helps to taper the bolt end a bit first. The hole in the cup is about he same size as the hole in the washer so don't get too energetic at screwing the bolt in. If a washer does not come out with just a little screwing you probably don't have one.

Here is a photo from one of our members (wish I could remember) who sectioned a head. It is a nice shot of what things look like in the injector and hot plug, Unfortunately, it does not appear to have a wavy washer in the hole. You can see that there is a gap between the nozzle tip and the cup without the wavy washer.

Paul

click on photo for bigger

Thru pre combustion chamber and cooling passage.jpg
'84 P'UP 2 wd diesel, 5 spd with 0.78 fifth gear and differential back to 3.73.

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Re: Injector heat shield washers

Postby Dongshoreman » Sun Jun 09, 2019 10:33 am

Thanks for the picture Paul. I'm almost certain that the washers are in there because when I shined my light in each housing I could see something that looked shiny/wavy inside.
Also, I have put a few thousand miles on the truck since I bought it, and I figure that if I was missing the washers I would probably have some signs of injector damage. When I pulled the injectors recently the tips had a little carbon on them but overall they looked like they were in good shape. If the washers were missing this whole time do you think my injectors would show signs of damage?
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Paul
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Re: Injector heat shield washers

Postby Paul » Sun Jun 09, 2019 4:18 pm

Dongshoreman wrote:If the washers were missing this whole time do you think my injectors would show signs of damage?


Yes, I think the entire tip of the injector would be carboned up rather than just a small circle in the center. Not sure that I have ever seen this though.

Damage? Not sure about that either.

Paul
'84 P'UP 2 wd diesel, 5 spd with 0.78 fifth gear and differential back to 3.73.

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Re: Injector heat shield washers

Postby Dongshoreman » Sun Jun 09, 2019 9:13 pm

This makes me feel secure, thanks Paul. There was definitely only a small circle of carbon on each injector tip, and they looked like they were in good shape.
1983 Diesel Shortbed