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Discussion Starter #1
So folks, I picked up a 6.5 Suburban... '94 2500 with 205k miles on the clock. Didn't run, assumed when I bought it that it was the IP at the worst or at the least, a new PMD was required. Boy was I in for some interesting stuff.

First, I replaced the PMD (30 second fix, thought I should try it first!) and gave it a shot... no go. Eventually started and ran for about 10 seconds and then shut off again.

Then, I checked for fuel coming out the sample port or whatever that needle valve is for, no good. There's a homemade and primative SVO setup (which should have scared me off in the first place) so I cut that hose and found there was absolutely no fuel. As it turns out, besides the other fuel issues the tank was bone dry as well (according to the gauge.)

So, I set up a backup pump (BTW, the $30-40 autozone fuel pump with 5.5-9psi seems to be a direct replacement for the stock lift pump at 1/3rd the cost.) from a portable can of diesel and it started up and ran beautifully. Since I bought my PMD from Pensicola, they were happy to provide to me the fact that the port I was looking at was the return, not the incoming fuel to the IP... however I trusted the judgement of the guy who built the SVO setup and sure enough it works.

Upon further inspection, the existing filter was changed and the guy left both o-rings (old filter's and the new filter's) on, so that was leaking with what little the stock lift pump was producing. Removing the filter led me to the fact that the liquid in the filter housing only faintly resembles diesel fuel in smell, and looks to be a mix of at least 70% water. Fortunately all the other things were against me or I'd have been pumping water through the IP and that would be $$. I'm hoping this is just the filter housing and not the whole tank, though to be safe it sounds like I'll be draining the tank and purging the whole system with a couple gallons of fuel before I can hook 'er back up :(

Heater lines for the rear heater are convieniently leaking prior to their arrival at the home-made heated filter, so I'm going to loop those in the firewall and hope the problem is solved. Also didn't have any coolant in 'er when I got it so that's probably another good sign, though before I shut it off it seemed to run *great*!

Looks like a new cooler line or two will be required too, a bit of oil but she's full and it doesn't appear to be leaking anymore... just runoff from the fuel that leaked.

So, next steps and I'll update it here when I learn stuff:

1. Draining existing fuel system, replacing lift pump and filter.
2. Plugging coolant lines for rear heat/SVO filter/etc
3. Removing SVO system completely and running new lines where needed

Then test drive time!

:D
 

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Discussion Starter #2
Truck runs and drives. Need to figure out a way to bleed the cooling system since I had that leak - top hose gets hot but doesn't have anything in it and I'm not getting anything on my gauge. Only drove it around about 4 blocks until I get the cooling system settled.

A couple small blips but that may be because there was still a bit of air in the filter, 2 pumps, etc.

It's a start!
 

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cool stuff. gotta like it when it's an easy fix to get it running, but I really hate to be the one to tell you the IP may now be toast. if the PO tried starting it with no lubricant, (diesel) well I shudder to think of the friction in the IP itself. I know when I first ran outta fuel, yup I knew I was low and figured just like a gasser a few clicks of the starter and I might be able to get to the gas station. took a few attempts but fell short. wouldn't fire up at all so dumped a jerry can of lubricant (diesel) in the tank and it ran for about 3 weeks before I fell victim to a dealer IP replacement under warranty. whoo hoo. hope your luck is better. Ed
 

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Discussion Starter #4
Definitely a possibility, even at 205k without all these issues. Comparatively, diesel fuel is a pretty poor lubricant compared to most viscosities of oil so I have high hopes that if the IP was already beat up, this didn't do much more to it :)

Only time will tell. Right now I'm running my spare fuel pump in-line with the old pump, which also goes through the veggie crap. Tomorrow I'm installing a proper lift pump and bypassing all that crap.
 

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to bleed your coolant.... there is a bleeder on top the t-stat housing...at least my 95 has one.....just crack it open tell the green stuff comes out...



btw i gave $2000.00 for mine!!....and put in a good hunk of cash in it!!
 

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Discussion Starter #6
From the pics yours looks to be in a lot better shape :)... hopefully this will be a good truck or I can sell it and get one. Was just a MINT 99 on ebay BIN for 10, not sure what it went for though.
 

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are you going to replace the oil cooler? my truck had leaking lines, looked like for a long time, radiator is soaked.
those lines can blow at anytime.
what happens when it does? oil is gone in just a minute.
lubrication specialist
the water in the fuel doesnt do a lot of good.
i think my WIF sensor is bad, it flickers occassionally, i dropped tank, fuel it clean. i installed a permacool 2micron/water seperator-final filter from heath for $150.
its easy to drain the tank, dropping it is doable alone, i used blocks at both ends and lowered a little at a time w/a trolley jack.
open t handle put hose in buckets or fuel cans. there is a red wire extending out of the wireloom near drivers fender and firewall w/a female spade, connect it to positive the LP will run.
when do, long funnel into filler and pour it back in.
my LP i bought HD from heath, worth the money. i use genuine oem parts as i can.
jon
 

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Discussion Starter #8
Porbably will only get to the lines if they leak more, not doing bad now.

I'm still getting some drainback so I think I'll replaced the fuel lines completely from near the tank to the IP with a checkvalve near the tank. Might just pick up a good Racor with water separator off eBay and make my own filter and buypass the factory piece of crap.

Still dealing with the cooling system issue (per other thread), think either hte sender's shot or there is still air in the system.
 

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Discussion Starter #9
Sender's fixed, truck gets up to temp fine.

Still stalling... I put some clear hose in front of my secondary lift pump to the IP and I can see when I run into problems, it's because air bleeds into the line.

Next I'm replacing the LP and the lines to be sure the air is out.

BTW, a HUGE and insanely inexpensive help in diagnosing these issues is a cheap 0-15psi gauge and some of the blue clear fuel line tubing... makes it easy to see if the pump is up to spec psi-wise and whether there is air getting in!
 

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Ishiboo, I picked up my Suburban for just a little bit more ($2600) with 300k miles on it, and it was running great. Worth every penny, I thinks. Might have a problem here or there that could use a little cash, but it sure beats a monthly payment on a new one.

One of these days I need to get off my butt and see why I lost a cylinder or two. I ran it almost out of fuel once, to the point it was sputtering pulling into the station, and within a week or so, the problem started. Weird thing is, I ran it completely out of fuel a couple weeks ago, and after bleeding the air out of the filter and re-starting it, it ran smooth for about a day. I think it's just a clogged or bad injector (or two).
 

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Discussion Starter #11
I think based on everything I've read and experience with a couple 6.5's with minor issues, a lot of IP issues are not the IP at all but bad grounds, PMD, fuel leaks, etc which are exacerbated as the pump ages.

As long as my bottom end is ok I am going to keep wrenching on this... it's cheap enough that I can put an ebay IP in and still make money if I have to dump it. Though replacing the IP seems liek a major pain in the ass, and nobody has instructions on it :)

As soon as I get all these fueling issues fixed I am probably going to ask (if it still occurs) why I don't get any boost (AFAIK... have a boost gauge but im not sure it works) and either way, no power. It revs throughout the band fine but it runs like a NA truck.
 

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" replacing the IP seems liek a major pain in the ass, and nobody has instructions on it "

there are instructions on the forum for IP changes you just need to delve into it.

" I am probably going to ask (if it still occurs) why I don't get any boost (AFAIK... have a boost gauge but im not sure it works) and either way, no power."

without boost it'll spill black smoke like crazy.. most likely the boost gauge is bad or poorly wired.
 

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Mine was showing a little boost when I got it, and then started throwing wastegate solenoid codes. ended up being a pinhole in the vacuum line between the solenoid and the wastegate. 'Nother cheap easy fix.

-Off topic, how hard is it to get to the injectors and/or glow plugs on the passenger side? That's one reason I haven't done anything about mine. I keep looking at the turbo and saying, How do I get to those things. It doesn't look any easier from underneath. I was thinking about pulling the fender liner, would this help?
 

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yeah pull your inner fender and have a stab at swappin them out ... and for every cuss you thro just think you could have a VAN like me lol
 

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Discussion Starter #15
Well, regardless of the gauge there's a power issue... and I'm not seeing much power at all. Really I don't feel any turbo spool, unless there's another parameter which is causing to accelerate poorly. I'm hoping it's a fueling issue and all will be well when I fix the supply-side line issues tomorrow :D

Would never want to work on a van... the newer dmax vans especially look like you'd have to pop the motor out the bottom just to do anything to it :)
 

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Discussion Starter #16
Was it recommended that people install the 93 lift pump instead of the 94? I see that hte 93 has higher pressure by a little bit... it's also about $26 cheaper @ autozone than the newer pump, though they appear to be the same construction.

Do these have check valves built in?

I wanted to plum these into some soft line, not sure where I can find M16 hose fittings for those pumps locally though on a saturday.
 

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Nope, no vans for me. I'll just grab my step stool and climb up under the hood. :bounce:
That's what those brush bars are good for, hanging on to, while standing on a tire trying to reach the air vent on the fuel filter.
 

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I bought mine for 4600 with 120k on it, and have done the heads, injectors, OPS, PMD, and more! So dont feel too bad!
 

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Discussion Starter #19
More surprises! Totally amazes me what the guy who put the vegitable oil kit in did.

I'm not sure WHAT was going on, however when the guy dropped the tank we found that they ran a coil of tube in the DIESEL tank and hooked that to the rear heat lines as well, almost as if there was supposed to be VO in there. Of course it was drilled through the tank and affixed with some silicon instead of a proper fitting.

Also the pickup unit's lines rusted off when we tried to remove the hoses so I couldn't put it back together tonight. Will have to wait until I can get a new unit. Good news is the tank looks pretty clean inside, actually very clean, and there's no serious rust around where its pinched together.

Removed the fuel manager or whatever you folks are calling it in the engine compartment and got some of the engine compartment lines run. I will not be returning the filter to its original spot, rather it will sit in the big empty space between the brake booster and the drivers side fender until (if?) I get the truck all sorted, in which event I'll get a nice filter for the frame rail. It's in a stupid spot anyway.

All in all, if this fixes my issues I'll be about $3000 in with labor (I brought a guy on to help with dropping the tank/the messy stuff as I'm running out of time) and all the parts.

Hopefully this solves the power issue.. otherwise next is the turbo master/vacuum pump removal. It seems like a waste to have all that sh*t on there when a really expensive spring will do :)

More updates Thursday night as long as I can get the sender/pickup unit tomorrow or Thursday from somewhere!
 

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Save your old sock and pay CLOSE attention to FSU install.

I am having an issue where my brand new tank and FSU seem to run out of fuel half way down. It's also clogging it seems. I havn't dropped the tank yet to verify problem, but it has to do with the FSU somehow.........................
 
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