Author Topic: So many lines! What do they all do?  (Read 25766 times)

Offline fmxr47

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So many lines! What do they all do?
« on: February 20, 2016, 08:32:49 AM »
I've got this k20 that was a 6.2 but now has a 6.5 td in it, I just got it and it has a biodiesel tank at the rear of the truck and a bunch of bs in between, I need to eliminate the biodiesel set up and I'm only using the passenger side tank and deleting the selector valve. I think there is a fuel heater of some sort because as you will see in the pics I have some massive hoses off these little solenoids that go straight to the therm housing into the head. Any info on this setup would be appreciated, or pictures of how the heater hoses should be routed along with the fuel hoses!! Thanks a bunch


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Offline 1967KaiserM715

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Re: So many lines! What do they all do?
« Reply #1 on: February 20, 2016, 11:22:43 AM »
Honestly, I would ditch the model 80 fuel filter(what is on the firewall) and get the FFM(Fuel Filter Manager) for the 6.5. OR get a remote spin-on

either way, you should have 1 line going to filter from the fuel tank, 1 line out(2 if using the 6.5 system-one would be for a water drain, the model 80 should already have that built in) going to the injection pump. then one line running back to the tank(this is your return, should be 5/16" line)

I honestly don't know whats going on with all the heater hoses, you need 1 coming from the coolant crossover to the heater core, then one coming from the heater core to the radiator. It does look like you will need to plug one port on the crossover, as it looks like someone drilled and tapped it for the extra lines, the reddish line towards the bottom of the pile should be the original heater hose going to heater core
Current Vehicles:1985 GMC K10(Daily) 1991 GMC K2500(Daily) 1975 Beetle(not running) 1985 Mercedes 300D(not running) 1952 M35    1967 M715(not running)
 1986 Chevy K30(under repair)

Offline fmxr47

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Re: So many lines! What do they all do?
« Reply #2 on: February 20, 2016, 11:38:34 AM »
i did find the stanadyne filter housing under the truck, this will replace my firewall one at some point in the near future, I need to pull it and clean it up


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Offline 1967KaiserM715

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Re: So many lines! What do they all do?
« Reply #3 on: February 20, 2016, 12:58:13 PM »
Oh, wow, bring that up front drop it back behind the intake, than it would be pretty simple to rewire for the fuel heater and wif sensor, following a wire diagram, I will recommend getting new seals while it is out and replace the bypass filter in it.

https://m.youtube.com/watch?v=CK-sd49yRiY

Then the wif and heater sensors both have an o-ring that go bad, you can try matching up at Napa, just make sure it is a bit on seal, most o
thers fail shortly after use with the diesel fuel

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Current Vehicles:1985 GMC K10(Daily) 1991 GMC K2500(Daily) 1975 Beetle(not running) 1985 Mercedes 300D(not running) 1952 M35    1967 M715(not running)
 1986 Chevy K30(under repair)

Offline fmxr47

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Re: So many lines! What do they all do?
« Reply #4 on: February 20, 2016, 02:01:15 PM »


It was a make shift water jacket around the bio diesel line.... Pretty sketchy lol


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Offline fmxr47

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Re: So many lines! What do they all do?
« Reply #5 on: February 20, 2016, 02:10:32 PM »


I have a line at the rear of the I take and also one off the injector return hard line, not sure where it goes :/ please help lol this system is a joke


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Offline 1967KaiserM715

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Re: So many lines! What do they all do?
« Reply #6 on: February 20, 2016, 02:57:52 PM »


I have a line at the rear of the I take and also one off the injector return hard line, not sure where it goes :/ please help lol this system is a joke


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OK, so first pic, one line(right on in pic) goes to top of injection pump, the other line runs to a hard-line(this is a short hard-line and runs under the intake, it returns to soft near rear passenger side valve cover). Both are part of the return system.

Second pic, the line exiting between intake runners should be the return, this is 5/16" and should go straight to the fuel tank. However the supply line could be routed there too, that should be 1/4", unless he changed the fitting on the injection pump.

At this point it may be easier to remove the intake so you can see everything. And I'll try taking some pics and marking out what should be what., my engine is out, but I think I could provide some better explanation.

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Current Vehicles:1985 GMC K10(Daily) 1991 GMC K2500(Daily) 1975 Beetle(not running) 1985 Mercedes 300D(not running) 1952 M35    1967 M715(not running)
 1986 Chevy K30(under repair)

Offline fmxr47

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Re: So many lines! What do they all do?
« Reply #7 on: February 20, 2016, 03:00:47 PM »
Thanks for all you're help, I'm getting it almost to where it needs to be!

Much cleaner in the bay now


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Offline 1967KaiserM715

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Re: So many lines! What do they all do?
« Reply #8 on: February 20, 2016, 04:54:33 PM »
looking much better,

here are some pics to help out


NOTE: your return appears to go over the valve cover, between intake covers, this is just the way the '97 was routed


NOTE: yours is slightly different, mine is the stock 97, yours looks like the earlier style, your injector return to tank is right beside the one that goes to the pump. Also you appear to be missing the water drain petcock, any 1/4 inch petcock would work, that line is always open on the 6.5 FFM so you need some way to stop the flow.

Current Vehicles:1985 GMC K10(Daily) 1991 GMC K2500(Daily) 1975 Beetle(not running) 1985 Mercedes 300D(not running) 1952 M35    1967 M715(not running)
 1986 Chevy K30(under repair)

Offline 1967KaiserM715

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Re: So many lines! What do they all do?
« Reply #9 on: February 20, 2016, 04:55:59 PM »
say how did they do downpipe from turbo? did they route it outside the frame then loop it back under and out the back?
Current Vehicles:1985 GMC K10(Daily) 1991 GMC K2500(Daily) 1975 Beetle(not running) 1985 Mercedes 300D(not running) 1952 M35    1967 M715(not running)
 1986 Chevy K30(under repair)

Offline fmxr47

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Re: So many lines! What do they all do?
« Reply #10 on: February 20, 2016, 05:15:02 PM »
It's inside the frame and it's a tight squeeze, I got all the fuel stuff done today, picked up a plug for the t stat housing and some new heater hose. Tomorrow I'll get it running and tackle the down pipe and the cross over


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Offline fmxr47

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Re: So many lines! What do they all do?
« Reply #11 on: February 20, 2016, 05:15:46 PM »
And thanks for all of those pictures, I'm going to pull the intake off at some point to powder coat it so I will probably put the filter housing in at the same time!


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Offline fmxr47

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Re: So many lines! What do they all do?
« Reply #12 on: February 20, 2016, 05:19:51 PM »
I will most likely have to cut clock and weld the dp back together to get it where I need it


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Offline roundhouse

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Re: So many lines! What do they all do?
« Reply #13 on: February 20, 2016, 08:32:16 PM »
Looks like they were running French fry oil.
You wouldn't need a heated hose for bio diesel


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Offline fmxr47

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Re: So many lines! What do they all do?
« Reply #14 on: February 20, 2016, 11:18:25 PM »
That makes more sense I guess, I never bothered to educate myself on the alternative fuels other than propane


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