Fuel Pump, Injector Pump, or somethign else?

[trentc]

I was getting the "water in fuel" light on with no power. I changed the fuel filter/water separator. I finally got the air out of the filter and problem seemed to went away.

So I thought.

Now the engine runs perfect while the engine is cool, but as it heats up the same symptoms start appearing again. As it gets hotter, fuel getting to the engine decreases a LOT. I trip across town took me two hours one day because I just could not keep fuel flowing. I ended up having to pour a little bit of diesel down the throttle body to get the fuel flowing again and engine started each time the engine stalled out.

So I am thinking since the fuel flow is now related to the heat of the engine, I am guessing it must be something attached to the engine. So my first guess is the mechanical fuel pump which is closest to the oil sump and exhaust manifold. So I went out and bought a new one for $20.

Anyone care to dispute my thinking it is the fuel pump?

If you all agree it is the fuel pump, you know what sizes in tools I need to remove the two bolts and the one metal fuel line that goes to it? I really hate getting under a vehicle and having to waste a lot of time picking through different sockets, wrenches, etc just to try to find a right fitting one and one that can reach those tight spots.

Thanks!

TRENT

[DmaxMaverick]

Probably not the lift pump. They usually work, or they don't. And when they quit, they will usually dump fuel out the weep hole (messy driveway). "Hot" issues are mostly associated with a tired injection pump.

As far as the tool sizes required, as many as I've done, I could only guess (it's been a while since the last one). You will be doing it all from the top or through the wheel opening, so having tools handy has never really been an issue. Use some axle grease on the pushrod to keep it up while you install the new pump (pack a little grease in the hole, and on the rod). Messy, but it works. It also helps to rotate the engine to TDC, to ensure the cam lobe isn't in the way.

[trentc]

Thanks a lot for the response DmaxMaverick.

I will certainly follow your advice. I have to wait until the weekend to get under the vehicle. due to the time it will take me to change it out. I give me two hours.

I'll let you know the results.

Trent

[trentc]

I did not start changing it out until today.

I got the new one on. Sometimes you wish you know who the "engineers" are who designed the location and parts to put on them so you knew who to choke when you meet them :D

I just spent 30 minutes getting the pump on in tight spot. Now for the line that goes to the engine. Now the line is no longer in alignment with the new one, thus I cannot get it to screw on it.

Any tips? I have tried bending it, but it is so hard to see which angle you need to turn to not to mention not so simple to bend it.

I guess I will be taking the fraking pump back off.

[trentc]

I removed the pump again and connected the fuel line to the pump.
After a while of banging, yelling, pushing, and cursing I finally got the pump back on.

It runs a LOT better than it ever did before.

Thanks a bunch DmaxMaverick!

[trentc]

It seems like "fix one thing and another goes bad"

I drove the sub around for a while and it functioned just fine.
I did not drive it Sunday, and now here Monday afternoon I just tried to start it. Now it is not getting fuel. Almost like the fuel drained out.

Any ideas while I go buy a battery charger and connect it to the battery? Looks like I may have have to pour some fuel down the intake.

[crashz]

Air leak at the new pump? Lines loosened while driving on Saturday? If an air leak occured at the pump, i could visualize the fuel syphoning back to the tank over time.

Good Luck!

[trentc]

Maybe air in that pump rather than a leak. I think if there was air leak then some fuel should be visible.

After charging up a few times and a some fuel (the engine hates ether/starting fluid for some reason) down the intake just before the next try in starting, it finally cranked up and ran.

After that starting issue was resolved, I took it on a long drive and eventually on the highway where I got up to a speed of 85-90 for a short time to make sure the pump was actually functioning properly.

During the whole trip I did notice the engine slightly laboring while idle at stop lights/signs. There were slight delays in starting again at stops.

However 16 hours later after siting over night, it cranked right up and purred like a kitten.

Hopefully I won't have any more problems.

Thanks for your input.

[Subzilla]

Just wondering, when you changed the fuel filter, did you you shaked any thing that looked really bad (lots of water or trash)?? If you got a bad batch of something in the fuel tank, it could have plugged up your new filter quickly. You might open the drain on the bottom of the filter (also crack open the bleeder on top) just for a second, let it drain into a glass container and see if you have something bad in there. If yes, keep draining until you see good fuel. You'll have to purge the air out of course. If there's alot of non-fuel crap, you might consider changing the filter again and check into draining the tank.

Plugged fuel filters can make our 6.2's do some strange things.

Check the cheap, obvious stuff first, then maybe again!

[trentc]

I do not think it is a filter issue. This is a different condition that is going on.

I am starting to think this is a glow plug issue. Starting the vehicle is getting more difficult. I am now at a daily basis of cranking, pouring fuel in, more cranking, more fuel, cranking, then finally recharging batteries. Then it is all started again until it starts after the batteries are recharged.

When this issue first started I only had to do this after the vehicle had been sitting for about two days. Now after 6-8 hours of sitting I have to start this starting process all over.

Would you agree it could be a glow plug issue?

[Subzilla]

Could be. How does it run once you get it fired up?? Does it smooth out after coughing a bit and cruise on down the road? Or does it do any surging or hesitating?

Easy to check glow plug system operation - pull out a few of the glow plugs, put them back into the connector, then ground the base of the plug, hit the glow light with the ignition key and see if they glow red. If they do glow, then the power supply is working but it could maybe still be the rest of the glow plugs that aren't firing. I would then pull out the rest and individually check. You can also throw a meter on the glow plug spade to check for resistance instead of removing them. I like the see that visual verification, though.

And if you don't have it already, buy your self a Diesel Page R&R/Troubleshooting manual. Worth it's weight in glow plugs!

[trentc]

Once I get it started, it will run just fine. I can even shut it off and restart it without problems, though as it sits after shutting it down it becomes harder to start as time passes.

Thanks for those tips. I will check the plugs soon as I can. I see at AutoZone new plugs would cost me about $90. crap.

[trentc]

I took it on another highway trip today and paid a bit more attention and now I am not so sure it is the glow plugs.

While at 65 and crossing overpasses I noticed it needed a bit more fuel while going up those hills. This is not normal behavior for it.

I was looking at the sticky thread on here on "Finding Air in the fuel system"
What is does not mention is what are the symptoms of air in the fuel system. I did change out the lift pump and that would have allowed air to get it.

So why would air stay in the fuel system and what are the symptoms?

The trouble shooting guide is a good idea, but I just cannot spend the money on it now.

Thanks again.

PS: Forgot to mention it seems like the fuel is burning too rich by the smell. Is that even possible?

PPS: It does contain two items of symptoms, plus I found some others via Google. Those do match what is happening to my engine. So it seems I just may have air in the upper fuel line.

[crashz]

The leaky areas will not always leak fuel. Just air. I think in the sticky, the poster mentioned that he had to pressurize the tank to see the leak. Found it, fixed it and the hard starts he was having disappeared.

I had the steel fuel lines rot on another 83 diesel that I had while in college. I replaced the fuel tank and then had issue with it running. Got so bad that it would stall out while running and left me stranded a few times. Took me a few days to finally find the leak and had run a temporary rubber line from the sending unit to the lift pump. Never had starting issues specifically, cause that motor was started with fluid every day (disconnected the GP system).

[Robyn]

I notice a mention of using ether.

DONT DO IT AT ALL
This is a real quick way to wreak havoc on your little diesel creature.

Glow plug engines and ether just dont mix.

Best

Robyn

[trentc]

The leaky areas will not always leak fuel. Just air. I think in the sticky, the poster mentioned that he had to pressurize the tank to see the leak. Found it, fixed it and the hard starts he was having disappeared.

I had the steel fuel lines rot on another 83 diesel that I had while in college. I replaced the fuel tank and then had issue with it running. Got so bad that it would stall out while running and left me stranded a few times. Took me a few days to finally find the leak and had run a temporary rubber line from the sending unit to the lift pump. Never had starting issues specifically, cause that motor was started with fluid every day (disconnected the GP system).


So would air stay trapped after changing the lift pump, or you think after changing the lift pump I did not seal the line well enough?

[trentc]

I notice a mention of using ether.

DONT DO IT AT ALL
This is a real quick way to wreak havoc on your little diesel creature.

Glow plug engines and ether just dont mix.

Best

Robyn

Yes I did notice on the labels under the hood, but I did recall a truck someone drove some years ago that had a built in ether thank and button to help it start in extreme cold weather, plus the label on the container said for diesel also.