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oldbooks
09-04-2006, 13:30
OK, folks, I am a total newbie to this type of activity, the truck, the problem, the diesel engine, the forum........ALL of it.........so, please bear with me!

I have a '94 Chev 3500HD with a 6.5L engine. For two years, it's been "turn-key" I don't use it much and it sat in my pasture for about 2 months with the fuel cap off then I went to get a load of hay last week. It started as usual, then died; restarted, drove 50 feet, died; restarted drove another 50 feet and died again. This is not a choking, sputtering death--more like someone turned off the switch--instantaneous.

Some time ago, I blew loose an oil cooling line and when the pressure dropped, sirens went off, all kinds of warning to "shut 'er down"......This experience makes me wonder if there is some kind of safety shut off, some sensor detecting water in the fuel which is shutting this engine down?

I've been crawling around under there trying to find a place to drain any accumulated water but find no drain cock. I found what I assume is an in-line metal filter housing, removed it but could get no drainig action from the pump (is it internal?)......even when cranking the engine, no fuel was pumped out of the line on the tank side.

I could be barking up the wrong tree altogether........I am at a loss.......any helpful suggestions would be appreciated. (Please don't tell me to lift up the radiator cap and drive a new truck under it........I've already thought of that)

BTW, I do have a lighted "check engine" light....been on since I bought it.....have never pulled the codes, don't have the facility.....but will say the truck ran fine for 3 years with that light on intermittently. This engine is new, replaced by the previous owner at 117.000 miles.....now showing 125K.

Thanks in advance for any help you can offer......

Ed

TurboDiverArt
09-05-2006, 13:45
I would guess condensation in the tank from the missing fuel cap? Condensation builds up in the tank, water drops to the bottom of fuel tank since oil floats. You started it and the water was picked up in the tanks sump. Engine ran fine until water hit the injectors. Water doesn't burn and engine stalled. Now no way to fire unless you get fuel to the engine. Would be my guess.

If so, get a new fuel cap. Drain fuel from tank and refill with fresh diesel. Purge fuel filter canister and replace filter. Purge fuel into filter and let some drain out to ensure you have all the water out of the lines into the filter. Probably best to crack the injector lines and let them bleed some to ensure that any water left in the filter to IP to injector lines gets out and does not return to your tank and start the process all over again. After purging things and you think you bled off enough fuel then tighten everything up again and try to restart.

Don't know if this could cause eventual pump problems if water was in the pump for a long time. May be prudent to change the fuel filter one more time after it's been running for an hour or so to ensure you got it all out. I would also change the oil too.

Art.

chickenhunterbob
09-06-2006, 08:12
The water drain for the fuel filter is a small "t" valve bolted to the thermostat housing at the front of the engine, but water in the fuel should also show as an idiot light on the dash.

For a 94 you can read codes with a paper clip or other similar wire to jumper the A and B pins on the diagnostic plug on the drivers side under the dash by your left knee.

Electrical (battery, ground, etc) connections should be cleaned and tightened.

Sounds though like a fuel problem, perhaps leaving the fuel cap off for 2 months has allowed a pail full of rain into the tank. Or dirt, that has subsequently found it's way to the filter and plugged it up.

Hard to know what metal filter housing you removed, if under the driver side frame rail, it may be the lift pump you are describing, this would also have an electrical connection. This is an in-line electric pump used to transfer fuel from the tank to the injection pump.

With the "t" valve on the thermostat housing open you should have fuel coming out while cranking, if not, you will have to diagnose the reason why not, could be the lift pump, oil pressure switch, plugged filter, etc.

oldbooks
09-16-2006, 15:14
Art and Bob,

I thank you for your help so far. I feel that I'm making progress here. I re-installed the lift pump, located the fuel filter, removed the old one (it looks bad!) and have a new one ready to install. Here's my current problem:

The old filter had 2 rubber gaskets and 2 metal washers fitted onto the filter housing. When I removed the old filter, these followed it out and got separated to the point where I cannot tell what order they go in.

Also, the filter has a little black rotating knob on top which seems to be a tightening device. I can't tell what it tightens or how.

When I try to replace the 2 gaskets and washers then install the filter, the black plastic retaining ring doesn't get far enough down on the filter housing to catch the theads.

I'm missing something here.......Can you help? Just imagine that you're telling your Grandmother how to install this thing.......she knows more about this than I do, probably! Thanks very much.

Ed

BTW, I did have the truck running for a few minutes without stalling.....but fuel was leaking around the filter because those gaskets were not right. I think my original problem was just the clogged filter......now if I can just get the new one in!

d
09-16-2006, 20:44
Howdy oldbooks.
I don't recall any spacers needed on replacing a fuel filter. I wonder if your old filter degraded and fell apart. I would suggest not using the washers or spacers.
The procedure I use when changing my fuel filter is:
1- attach a hose on the water drain/bleed valve (on t-stat housing) running to a bucket on the ground. Dosen't matter if the hose is clean or dirty, just needs to fit and be long enough.
2- with engine running, open water drain valve.
3- fuel should come out and engine should still run. (important for checking lift pump)
4- shut engine off and hurry to open that black rotating knob on top of fuel filter that is about to be replaced. This will allow a siphon effect on the water drain valve/hose to drain some of the fuel out of the filter housing.
5- when fuel stops comming out, close water drain valve (on T-stat housing) . Unscrew big black ring on filter housing. I usually use an oil filter strap wrench or a big set of adjustable pliers.
6- pull out old filter by the plastic coated paper tabs.
7- clean inside of filter housing. I use a syring to suck out all the fuel and dirt. There may be particles in there or water. Get it clean. A paper towel or a rag would be my second choice because of dust or lint, but better than leaving dirty fuel or water in there. A turkey baster has been suggested if your wife can part with it.
8- when putting in the new filter, there are long and short tabs sticking vertically out of the filter housing on the truck. If you look at the underside of the metal dome of the new filter about to go in you will see there are long and short slots. The slots will allow the filter to go in and fit tight only if you have the long tabs lined up with the long slot and the short tabs lined up with the short slots. I have also had problems with the O-ring underneath the dome falling out. So make sure your comfortable with the filter staying together as you are puting it in. It is not a timmed event.
9- Screw big black ring back on with oil filter wrench or big adjustable pliers. Not too tight.
10- Close water drain valve and remove hose.
11- Open little black rotating knob on top of new filter about two turns.
12- On passenger side fire wall in engine compartment is the electrical fuse for the fuel lift pump. It is in a weather tight connector and you may need to remove a plastic cover to get to it. On that platic cover it says fuel pump fuse. The weather tight connecter of mine has an orange gasket that keeps moisture out.
13- un-snap the bottom half of that weather tight fuse holder.
14- pull atc fuse out and reinstall with one blade of the fuse out and one blade of the fuse in one of the slots for the fuse holder. What you are trying to do is power your lift pump with 12 volts thru the fuse and to the lift pump so you can bleed the air out of your filter and filter housing. If no power or spark happens, reinstall fuse to other side of fuse holder with other blade of fuse exposed.
15- Put exposed blade of fuse on another stud of the junction block. I don't remember if you have to have you key on. This will provide 12 volts to your lift pump. You should hear the lift pump running with engine off.
16- With lift pump running it should push fuel up and air out of the black rotating knob. This is the air bleed screw. When fuel runs out of air bleed screw, turn it closed (clockwise). When fuel comes out (hopefully) it may come out the top openning or between the black rotating knob and the dome of the filter. I put a few paper towels around the filter to absorb the excess fuel.
17- When air bleed knob is closed no fuel should come out and you can quit touching the fuse to the positive power supply.
18- reinstall the fuse to the lift pump in the oringial position and back in the original location.
If everything has gone right you should be able to start your engine with the fuel purged of air.
Find out the codes that have been set. They are important info for a long lasting engine. It is handy that the truck has a self diagnosting system. It only takes a paper clip to ground out the diagnostic port under the steering column and find out the codes. This website has all the info on how to do it and what the codes mean.
If you have water in the fuel add a good fuel additive such as stanadyne. If you suspect you have lots of water, drain the fuel tank from the bottom. You will hate to get rid of a lot of diesel, but it will be cheaper than repairs to the parts that the wet fuel comes in contact with.
good luck.

Bnave95
09-17-2006, 01:50
Be carefull with step 9. All I have ever done was to hand tighten only.
Removing ring in step 5 has also been by hand. Not sure about being able to get the new ring any more. I've had an extra one for years just in case. Jim B recamendation. Once this ring is off the GM parts self,there gone.
BTW, good write up. I still remember my first time with filter change:D

TurboDiverArt
09-17-2006, 19:58
Sorry, didn't get online all weekend until now. I agree, there are no spacers or multiple gaskets that I know of. I would remove all the lose stuff you have and just install the new filter. If should have a gasket attached to the metal top. If your old filter did not have the black plastic knob on top then I think someone might have substituted something else in its place, hence the need for extra spacers and gaskets maybe.

The filter is also keyed. It only sits all the way down one way. I think the larger of the keys holes on the filter top goes forward. If you look at the filter and compare it to the canister it's pretty obvious which one is the larger hole in the filter and which key is the larger one on the canister. If they are not correct you'll also leak fuel like you did.

I have always used an oil filter wrench. When I got my truck I couldn't get the ring off so had to use one. I have used one ever since. I don't crank it down but put it on tight by hand and then a little twist. Never thought to check if hand tight would seal, might have to try it next time.

Art.

oldbooks
09-22-2006, 17:37
Thanks to all your help, my truck is on the road again!

A brief synopsis:

1.) My problem was simple: clogged fuel filter

2.) The replacement filter I purchased was missing the rubber o-ring under the dome. Those old rubber rings and aluminum washers which were on the cannister really confused the issue. I tried to make them part of the system when they didn't belong in there at all.

3.) Today, I went to another parts store and asked to look at a filter element and, lo and behold, it came with a rubber gasket under the dome! Installed it, tightened down the ring and away she went without even a tiny leak.

It's really aggravating to deal with a problem when you have no previous experience with the parts involved and then someone gives you a faulty replacement part which you expect to be right. You fellows have been a real help and I much appreciate it.

I wish I'd live long enough and learn enough to someday be of help to you......not likely however.