Fuel filter change nightmare

[CROM]

OK, a simple fuel filter change has turned into a nightmare. Here's the deal: I drained the existing filter by loosening both vents (top and bottom) pulled the old filter off, pre-filled the new one and installed. Tightened the lower vent, left the top vent open and fuel cap open. I ran a small tube from the vent port on the top left side of the filter housing up to a bottle that I can see from the drivers seat and disconnected the pink solenoid wire. (both negs on both bats disconnected during removal/install and connected now)

The problems began when I couldn't get the fuel system to bleed. No matter how long I cranked, I could not get fuel to flow out of the tube. I have half a tank of gas and am on a slight incline in my driveway. I cranked until my batterys just about died and I had to charge them. Then my 'diesel mechanic' neighbor came over and suggested I had air lock. He suggested spraying WD-40 into the intake and turning the engine over. After a few goes, the starter started whining and eventually quit trying at all. I'm currently letting things cool down, including my head, and am in need of your expertise! Please help!

 

[CROM]

Update: After letting things cool off, the engine will turn over again. This eliminates a burned up starter, right?

So, I'm in the same spot I was...unable to get fuel out of the tube....any tips, tricks?

It rained all day yesterday and I can feel the mud drying already.

 

[allrevup]

Sir, It was a wile back the last time I did mine
but, I think you are bleeding the air out of the wrong bleeading port
everything else sounds correct, you usually just need to crank the engine with the pink IP wire disconnected for a few seconds, certainly less then a minute...
Check out youtube.com for a neat trick by aboonski, in Florida to collect the fuel with a clear container. I think is under CUCV

 

[CROM]

Allrevup: That's the video that gave me the idea of running the line up to where I can see it from the driver's seat. Based on the tec-manuals, I believe I'm watching for fuel in the right spot....anyhow, I'm getting no fuel comming out of nowhere...

 

[wallew]

http://www.steelsoldiers.com/cucv/65355-fuel-pump.html

http://www.steelsoldiers.com/cucv/36435-my-cucv-spin-fuel-filter-mod-2.html

http://www.steelsoldiers.com/cucv/60860-no-fuel-filter-first.html

OK, if you read my posts in those three threads, you will see I have an electric fuel pump inline the fuel tank. I just replaced it a couple of weeks for $48. It replaced another electric pump that was making all sorts of noise. So I replaced it.

for $50 it solves all sorts of problems.

The OTHER issue you may be having is air in the fuel line. If you do have air in the fuel line, it will be a mother to start.

You can be getting air in the fuel via an air leak in the fuel filter backing plate.


THAT'S MY GUESS. generally there is a guy on ebay that sells the fuel filter with a backing plate AND the mounting plate. The backing plate comes with two sensors already mounted. I think the last time I got one, they were less than $100 shipped.

 

[allrevup]

I just looked at the video and you are at the right port the top side!
Was you vehicle running/operable before the filter change? are your wait /and water in fuel light coming on during the starting prosedure? you may have accidentally disconected one of the 3 connections at the filter base??

 

[wallew]

Disconnecting the sensors in the fuel filter backing plate should NOT make a difference in STARTING

I could be wrong, but I don't think so.

 

[CROM]

Wallew, Allrevup: Thanks for the replies. One thing I should have mentioned is that the truck was starting/running just fine before I pulled the filter, which leaves me to believe I or my actions are the probable causes of failure here. Gas cap off, top vent open, pink IP wire pulled, half a tank of fresh fuel and still won't bleed.

 

[allrevup]

I believe you are correct in that you do not need to have of the sensors connected for the vehicle to start unless is winter you may need the heater. I was encouraging retracing his steps and looking for something easily overlooked

Disconnecting the sensors in the fuel filter backing plate should NOT make a difference in STARTING

I could be wrong, but I don't think so.

 

[caladin]

I believe you are correct in that you do not need to have of the sensors connected for the vehicle to start unless is winter you may need the heater. I was encouraging retracing his steps and looking for something easily overlooked

I dont have the 2 sensors connected and it starts fine. Post a couple of pics of the filter when you are about to attpemt to start it. Sometimes its somthing simple that the eyes misses.

 

[allrevup]

I would retrace what you did today during the fuel filter R & R.
Occasionally having a hard time restarting this trucks after replacing the filter, due to air in the lines can be normal, but sound as if you follow the correct procedure.
I guess is possible that something else rear its head or you have way more air in the system, that will required draining at the line/injector and a little more involved.
I better leave it to the manuals and people with more experience then I.
You said she was Running fine before, I say double check what you did and peripherals.
As an example the last time I changed the air filter and clean the housing, I mess up the 26 year old pink wire with the large white connector clip going to the IP pump. Took me a wile to find the problem, it look fine but is was not making 100% contact. A large heat shrunk wire terminal and dielectric grease took care of it.

 

[91W350]

Tighten both drains or bleeders. Crank the engine a few revolutions, then open the top one until you hear a hiss, repeat a couple of times. You should start getting shots of fuel with lots of air and as you go, you will get more fuel. I like to fill my filters before installing, some dribbles out, but it makes it much easier to get started. I am not sure why, but sometimes the lift pump does not prime so well with an open bleeder, maybe the lack of pressure lets the check ball float in the line or something. I am not sure how that check valve in the lift pump works. One of my M1009s will not prime with that top bleeder open. Hope it helps, Glen

 

[motormayhem]

Try refilling your fuel filter so you have some fuel draining back to the lift pump. You could also try cranking it with no filter on to see if you can get fuel from the filter base.

When I changed mine it took about 10 seconds of cranking to re-prime. Then reattached the pink wire and it fired right up...revved itself a little,sputtered,stalled....restarted and it loped a little and was fine.

To me it sounds like you either have a bad lift pump or the check valve in it is worn out.

 

[1983M35A2]

someone told me to put gas on a rag an put it over the air intake. i don't know for sure if it will work.he is a diesel mech

 

[CROM]

I'm currently trying to crank the engine with both vents closed (thanks 91W350), but the batteries are prettly low. I've got them charging now. Also, when I crank the engine, it sounds like there's a 'low' spot when it turns over. Is this a possible starter problem?

 

[CROM]

Allright, no pressure getting to the fuel filter housing...no hiss when I open the cap after cracking on it....any other suggestions?

 

[ryan77]

Change the lift pump there cheap! Charge batteries and try again. Ive heard of 6.2 and 6.5 running with a bad lift pump it puts extra strain on the injection pump!! But normally if that were the case you would have other symptoms before the filter change like hard starting etc!!!!

 

[motormayhem]

Sounds like your lift pump is bad. You could try blowing out the fuel lines to eliminate a plug in the lines.

 

[CROM]

Thanks, guys! Lift pump? Sounds like a plan. Of course, I'll have to wait until tomorrow to get one as nothing is open today. IF that doesn't solve it, what's next on the list of possibles?

Also, would spraying WD-40 or ether into the intake while cranking help or hurt?

 

[BIG_RED]

This happened to me when I replaced my lift pump.

What happened to me was that fuel had drained out of the suction line between the tank and the lift pump, and the lift pump couldn't suck the air out of the line since the check-valves in the lift pump need to be submerged in a liquid to work. (Obviously my problem was not helped by me having a bone-dry brand new lift pump).

I know you did not replace your lift pump, BUT:

Are you running the original (or pre-'89) lift pump?

The reason I ask is, the original lift pumps on these things (6.2's) had some kind of stupid drain-back system with a tiny air hole on the side of the pump. Supposedly(not confirmed), this was because the diaphragm in the pump did not like diesel and would get soft and rip if it were submerged in stale fuel. So there was a tiny air hole that would let air into the pump so that when the vehicle was parked for a long time, fuel sitting on the diaphragm would flow back into the tank rather than getting stale in the pump and eating the diaphragm.

This lead to these vehicles needing more cranking to get going after sitting for a long time. GM eventually learned how to make better diaphragms that could withstand the diesel, and pumps made in '89 or later do not have the tiny air hole, and start easier after sitting for a while. The '89-and-up part is now the part that parts stores are supposed to be selling everyone with a 6.2. (If you're not sure you're getting a newer pump, ask them to look up an '89 suburban and see if it's the same part number). When you clean up your old pump, you'll see the tiny hole I'm talking about, and notice the new one doesn't have it.

Sorry for the history lesson - I find it interesting and thought you might like to know.

My guess is, your lift pump has worn out check valves that need to be totally submerged in fluid to work properly - and fuel drained back out of the suction line while you had the filter off(which lets air in). (When the filter is on, it's like when you dip a drinking straw into your milkshake, cover the end with your finger, and lift it up. The milkshake(diesel) stays in the straw(hose) because your finger(or filter box) doesn't let air in.)

I think a new lift pump is probably not a bad idea.

The way I've been priming these lift pumps is going and finding a few feet of 3/8" clear hose and a short piece of 3/8" pipe (or coupler nipple, etc.). Then I pull off the hose on the filter box that leads to the pump(the bigger hose) (it goes under the intake manifold to a steel line, where it goes down the front of the engine to the lift pump) and connect my short piece of clear hose to it. Then I put that in my mouth (since I didn't have a vacuum pump at the time) and sucked my face off until I saw fuel in the clear line. Then I pinched the black line from the truck, disconnected my clear hose, stuck the hose back on the filter box (which I had already filled with fuel, loosened the air purge valve at the top, and had one of the neighborhood kids standing around with his finger covering the input nipple so the fuel didn't drain out) and had the kid crank her over. Fuel shot everywhere pretty quick (two seconds). Then I closed the purge valve and cranked it with the accelerator to the floor until she roared to life (maybe 5 seconds).

I replaced all my rubber fuel lines, the lift pump, my fuel filter box (Spin-on filters are things of beauty), and a metal line that I kinked in the process. Now my truck starts like a dream. It was well worth it.

Good luck.