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GoLions95Burban

GoLions95Burban

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Location
Northern Virginia
well, I knew it would happen.......

95 suburban stalled out on be and left me for dead! got the 6.5 TD and 78k miles. Its my daily and I had many things lined up to work on. Engine starts every time but as soon as you put her in gear and go she stalls out ( no power steering, but electronics still work ). I will stop, out in park, start up again, and the same thing happens again and again. first off...its not the PMD...i JUST put a new one in ( relocated of course ) from quadstar. Second, I have the following parts on order from Leroy Diesel.....Raptor lift pump, lift pump relay harness, new fuel filter manager with the feed the beast mod, new oil pressure switch. Im also going to change the fuel shut off solenoid. If all that does not work, Ill try the optical sensor. So, my question would be, aside from all that, other than total injection pump failure ( I do not think it is because it would not start at all, right?) what could it be? I hear the grounds are infamous for getting all buggerd up and I plan on going through and tidying those up, but that cant be it can it? would I not lose all electronics too if that were the issue? WISE MINDS PLEASE BESTOW YOUR KNOWEDGE UPON ME!!!
 
It will run with a bad injection pump. It just won't run good. So don't rule that out. The guys will tell you how to test the injection pump pretty simple procedure. grounds can cause any kind of problem you want with these trucks. Especially the ones kind of passenger side of the engine at the back where there's a bunch of lawyers on one stud grounding them all. Just a side note, just because you put a new PMD in it, doesn't mean the new one is any good. So don't completely rule that out either.
Does it run okay when it's sitting in park?; As in it does not idle rough or anything?? If it were me the first things I would check would be to the fueling system. Could be that it's not getting enough fuel or the fuel isn't any good, last year I had a similar issue and come to find out the fuel I had gotten had a lot of water in it.
. Some of the guys will chime in later on that are more experienced than I.
 
Make sure you're getting fuel to the Injection Pump/ IP

A permanent fuel pressure gauge is a good upgrade.

Don't throw parts. New, bad parts are way too common and can mess up diagnosis.

Try running with the fuel cap loose.

Jumper the lift pump. I think on a 1995 there might be a short wire coming out of a big loom, below and between the under hood fuse box and the firewall.

I install a on/off toggle switch there. Your lift pump relay upgrade harness, should come with an on off switch.

Run about 1/2 gallon out the T drain.

You can leave the lift pump jumpered while trying to start.

If you're losing power check all fuses and connections. Fuses can have continuity across and possibly not be making connection in the fuse panel.

Sometimes cables rot inside where you can't see.

I took to replacing the engine harnesses as I worked on these.
 
Fill out your signature line- it seriously helps.

trying to remember your other posts … didn’t you have some transmission stuff recently? TC might be locked up. Think like a manual trans and you have the foot off the clutch. Put in gear and engine dies. A quick test for this is chock the front wheels, rear axle on jackstands with tires 1” off ground in a position where of the truck jumps forward, it will not hit anything. Start it up, foot on brake, shift to neutral. Foot off brake shift to drive. Wheels should just spin and engine runs at idle. Then slowly press brake pedal. Engine should run while wheels stop spinning. If the engine dies, your TC is staying locked up for some reason-
You don’t have an aftermarket switch to manually lock it l, do you?
That factory wire people tap for doing that - it can be grounded out and cause this.

Outside of the above test- post a video of it happening to youtube and post link here.

Knowing no air in the return line and knowing fuel pressure at the ip inlet is a good thing here.
 
Thanks fellas, I've driven it around the neighborhood a couple times and it has not stalled out, but i do get some hesitation when I hammer down on it, like sputtering/skipping. I ordered Leroy Diesels " big Chicken dinner " kit, which is the Raptor LP with a pre filter filter added. Thing is, the kit calls for new fuel line running all the way back to the FSU... which involves dropping the tank, which I've never done before. I count 4 bolts but if anyone wants to throw me a bone as to the process of doing so Im all ears!
 
the LP will help. that sputtering skipping your feeling is most likely from air getting into the line. replace your 1/4" return line off the IP with some clear tubing from the local hardware store. it's about a 6" piece you'll need. then watch for bubbles coming out of the IP.
 
dd that fuel pressure gauge and it NEEDS to be tapped in a metal fitting attached to the ip inlet. Modmafia sells one - they don’t have it custom made, it is source-able.
I can’t explain how critical this is.
The clear return line from hardware store has to be replaced every few years but is easy.
Or get a piece from fuelline.com- theirs is rated for pure ethanol and even nitro methane.
We have ethanol in our diesel fuel now and it is rotting away the old fuel line.

When you do all this install, drop your tank a couple things to do at same time. Replace all the old style rubber fuel line with sae30r9 or higher fuel line. That is the one that won’t deteriorate in the ethanol. If you are adding an external pre filter, when the tank is down remove the “sock filter” from inside the tank pickup tube. The coating in the tank flakes off and will plug up the sock filter. By removing it the tiny chunks go through the tube and the external pre filter catches them. When enough has came off- you just spin off that filter and spin on a new one instead of dropping the tank again.

On the tank- 50/50 atf and acetone is an amazing rust removal on youtube “project farm” did comparison videos of best ones… I cant remember which won but 50/50 did well. Soak the strap stud threads. I usually use a pair of needle nose vice grips to hold the strap when possible and hit the nut with my 3/8 impact to remove when it gets to that point.

I’m going off many years memory so guys jump in if I miss a step.

Start by soaking the studs twice daily if you aren’t getting to it right away. Disconnect ground battery cables. Syphon out tank best as possible. I do front and rear axle on jackstands, I prefer lots of room. Safety googles are good- I keep a pair of swim goggles in my toolbox for dealing with fuels. Now those go on. Remove rubber filler hose. Break free, loosen strap nuts most way down. Then I use a trans jack. (No, not Jill who is in the wrong body) a regular floor jack can work but is a pain to balance the tank. With straps loose you can find balancing point when lifting it slightly. Remove the strap nuts all the way. Lower tank slowly, then you can get to the fuel lines and electrical to disconnect on top of the tank. Then tank comes down all the way, and you can finish cursing at truck. Oh, one trick is, use a sharpie and trace the outline of the jack mount so when you put it back on you can see where it goes. A real nifty trick for the longer tanks that come down half full.
 
What's that bulk rubber fuel line type # ? sae30r9

I saw a post that said to use sae30r9 of fuel line or better. I'm not sure what better is.

The last time I ordered fuel line it was manufacturer direct. There's a thread here someplace. Greg was still here then.

I know I'm getting low on a size. I Don't remember which size. And the clear and yellow fuel line I ordered seems to have been a wasted of money. It seemed to harden, just being on the shelf in the shop.

I'll have to try this link, next time.

Don't be surprised if the fuel tank doesn't drop easily. I've had to pry them loose to get them down.

fuel-line.com

Fast Flow Fuel Line

Premium quality colored fuel line in 1/8", 1/4", and 3/8". Zip Ties, & Filters.
fuel-line.com fuel-line.com
 
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Thanks guys, just waiting on parts in the mail at this point. On a side note, once I get this Raptor LP in, along with the new FFM that has larger fittings ( FTB mod) shes gonna be getting enough fuel, but might need more air to go along with that. Any recommendations as far as a new air box goes? whats yalls favorite? The market has plenty of options but before dropping the dough I figure ill get some feedback, thanks!
 
GoLions95Burban said:
Thanks guys, just waiting on parts in the mail at this point. On a side note, once I get this Raptor LP in, along with the new FFM that has larger fittings ( FTB mod) shes gonna be getting enough fuel, but might need more air to go along with that. Any recommendations as far as a new air box goes? whats yalls favorite? The market has plenty of options but before dropping the dough I figure ill get some feedback, thanks!
Click to expand...
Stock K47 air box. 1996? And newer.
 
@jrsavoie
The sae30r9- next step up is sae30r10. That is thicker and a little harder to work with.
I wouldn’t go with anything beyond that.

@GoLions95Burban
Have you thought about just doing the complete system with that lift pump? The water separator and filter are both better than the ffm. Then only thing you are missing is the fuel heater- if you need one you buy it separately and just screw it in. You can go with a larger heater, Run the existing wire to the fuel heater to operate a relay, Then run larger wire to the new fuel heater. Or just extend the fuel heater wire if you stay with a small unit.

I used to love the ffm and the filters used to be low cost for good Delco filters- but now most the filters suck and the good one (wix/napa gold) is pricey.

My new build will be running fass pump & filters. That ffm is going away. I will have a fuel pressure sensor at the ip inlet, another just before the filters. Those two wires feed to a single pole double throw switch. Output from the switch to the gauge. So switch in normal position = read ip incoming fuel pressure. Flip switch and read pressure before filters. After a little testing I will be able to replace the larger fuel filter based on it getting full and actually due for replacement rather than random mileage or hours used.
This is a little more than most want to do, but better filters means longer and more reliable ip & injector life. The switch and second sensor means money saved not replacing filters way too soon paying for itself and also instant diagnostics should something go silly.

If you stay with the ffm, I suggest a better water separator.
If you want the dual sensors- Leroy sells a fitting that reads fuel pressure on top of the ffm- that is a prefilter location.

To be clear the factory ffm/ filter is ok for cleaning as well as a descent heater- just lacks in water separator. If you ever get wif light and drain any water- replace your filter immediately. As in, when I to on road trips where I might encounter water in the fuel, I have a new sealed filter with me. It takes very little water to destroy an ip, and same for the injectors. iirc the bench test we did shows the Delco filter did the best (before wix made one) and it safely stopped 2 tablespoons of water. But running the lift pump against that amount for 10 hours had it pushing water through. Adding 3 tablespoons had it failing in less than half hour.

The reason I lean towards Fass filter- is will cease flow. No water is going through. This is their new one that doesn’t have a drain.
When a large filter like that starts getting plugged, you will feel loss in power, but sooner than being felt you will see a drop in fuel pressure at the ip.
 
GoLions95Burban said:
Thanks fellas, I've driven it around the neighborhood a couple times and it has not stalled out, but i do get some hesitation when I hammer down on it, like sputtering/skipping. I ordered Leroy Diesels " big Chicken dinner " kit, which is the Raptor LP with a pre filter filter added. Thing is, the kit calls for new fuel line running all the way back to the FSU... which involves dropping the tank, which I've never done before. I count 4 bolts but if anyone wants to throw me a bone as to the process of doing so Im all ears!
Click to expand...
I’m just now catching up on this thread. I have not read all of the posts.
I do hope that instead of dropping the tank, that, someone mentioned that it most times is easier to lift the box to get to the tank sending unit.
Works especially well on trucks with in tank fuel pumps thats failed.
Lifting the box is best, unless, You are dealing with a lot of rusticated in fasteners.
 
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