The 99 is smoking again.. Why?!?!

[trackspeeder]

Maybe the restriction is in the tank?? Shtuff clogging the pick up.. Hmmm. I'm surprised the engine ran with 5lbs or pressure.

 

[EMD_DRIVER]

Maybe the restriction is in the tank?? Shtuff clogging the pick up.. Hmmm. I'm surprised the engine ran with 5lbs or pressure.

Nick said that he did the intank mod to it...

When it hit 5lbs. It started stumbling pretty badly...

 

[trackspeeder]

Nick said that he did the intank mod to it...

When it hit 5lbs. It started stumbling pretty badly...

Rule out the tank restrictions. Tank mods will keep that from happening.

 

[EMD_DRIVER]

Rule out the tank restrictions. Tank mods will keep that from happening.

I do have a bed tank, with supply and return lines... I know that line has no restriction... I may hook into that and see what happens..

 

[Double-S-Diesel]

bettin check valves are plugged, they are attacched to the fuel line where it enters the head, they are part of that fitting.

 

[EMD_DRIVER]

bettin check valves are plugged, they are attacched to the fuel line where it enters the head, they are part of that fitting.

Can I simply remove them? The system doesn't hold any pressure anyway. Once the fuel pump shuts off, the pressure in the fuel rail drops.

 

[EMD_DRIVER]

I decided to drop the fuel tank and see if there were any problems. I hooked a Holley blue to the line from the tank and pumped it out. To my surprise, I got a LOT of air bubbles! I traced the line along the frame and everything looked good. My only guess, would be either the factory fitting that hooks up on top of the tank, or the factory braided line that attaches to the steel line. I cut the braided line off and I will be replacing it. Hopefully, it will cure the air bubble problem.

When I pumped out the tank, I was surprised to find it totally empty! There wasn't even a half-pint of fuel left in it. I pulled the pickup/sending unit and had a look... Everything was still nice and tight..

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The inlet screen was also clean...

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I did find a small bit of sludge in the tank, as well as a stink bug. They are both gone now...

 

[EMD_DRIVER]

I replaced the push lock fitting and the hose to the intake side of the fuel pump. Hopefully, I don't have anymore air problems to worry about. I have a filter and head to mount pre-pump, as soon as I can find threaded fittings that fit the threads.. I believe they may be 7/8-14 UNF, so I'll have to look around for those fittings locally.

Even after replacing the push lock fitting, I am still having pressure drops. Nick told me to check the fuel line check valves, where the lines go into the heads. That will require me to remove the downpipe and the accessory bracket, that holds the PS pump and alternator on. If the check valves aren't vitally important, I plan to re-route the fuel lines so that they feed both sides at the front. All I would need, is a tubing bender and some brass fittings..

 

[Double-S-Diesel]

with the dead head fuel system you need the check valves, they keep the injector pulses from blowing the filter out.
if you do the regulated return then they cane be modified or eliminated.
the stock lines dont bend really well.
whe I have done the regulated retrn or my custon setup on the OBS, I used 1/4"heavy wall seemless tubing, it would bend and not kink, the thin wall stuff would colapse.

with a stock pump I advise not to put a filter before it, they dont have the power to suck through them.

 

[EMD_DRIVER]

with the dead head fuel system you need the check valves, they keep the injector pulses from blowing the filter out.
if you do the regulated return then they cane be modified or eliminated.
the stock lines dont bend really well.
whe I have done the regulated retrn or my custon setup on the OBS, I used 1/4"heavy wall seemless tubing, it would bend and not kink, the thin wall stuff would colapse.

with a stock pump I advise not to put a filter before it, they dont have the power to suck through them.

For now, I guess I just need to check them. What am I looking for? gunk, obstructions, ???


On a side note... The 97 started smoking too.. It got really bad today and burned 10 gallons of fuel, to go 72 miles! What is going on?!?!?!

 

[EMD_DRIVER]

I pulled the check valves out today and cleaned them as best I could. They are still pretty hard to even blow air through. They must be one heck of a restriction!

Since I already had a regulator, I bought all the parts necessary to make my own custom regulated return system. We'll see how that goes!

 

[EMD_DRIVER]

Here's an update...

I installed a custom regulated return system on the truck, since I already had a regulator and only needed tubing and fittings.

Once I got the system installed, I kept having fuel pressure pulsing problems. I thought there was a blockage in the return line, but I was able to blow air through the line and into the tank. I was worried, that I had gotten a bad regulator. I figured out the problem and fixed it tonight. It turns out, that someone had assembled the regulator wrong. On the spring side of the regulator there is a valve seat, the spring and a bottom seat under the spring. The adjustment screw presses against the bottom seat and applies pressure against the spring. The spring presses against the valve seat, which presses against the diaphragm. The bottom seat was in the bottom of the regulator at an angle and applying uneven pressure to one side of the spring. Once I put it in correctly, I cleaned the various parts and re-assembled the regulator. Adjusting it was much easier and there is NO pulsing of the pressure!

I put everything back in and went for a test drive. The pressure settled out at 60PSI idling. While maintaining 55MPH, The pressure dropped by 5PSI. Under WOT, it dropped 10PSI. My minimum pressure at WOT was 50PSI.. I can adjust it if I need to, but it was happy where it was.

Having solved the smoking problem in the 97 with the water injection, I believe it will solve the smoking in the 99. I guess I got a batch of WMO, that had a lot of synthetic in it. Synthetic oil will produce a lot of coking of the rings and exhaust valves. The water injection system on the 97 cleaned the coking out and it doesn't smoke at all now. Once I get the water injection installed on the 99, I will report back!

 

[zpd307]

can you do a write up on your diy regulated return gary? pretty please...... you have an early 99 just like me.

 

[EMD_DRIVER]

can you do a write up on your diy regulated return gary? pretty please...... you have an early 99 just like me.

Hey Gary...

As soon as work allows, I would be glad to write it up. I am having some fuel pressure drop issues still, but not as bad as it was. I will probably end up running a larger diameter line from the tank to the pump.

I'm also having a very small fuel leak and I believe it's coming from the rear of the passenger side head. I had a hard time with that port and may re-design the way I access it, with the fuel line.

I'll post it up as soon as I can!

 

[zpd307]

sweet! much appreciated. everybody wants an arm and a leg for their kits and most peope just say to buy the kit whenever someone asks about a diy. i also all ready have access to a regulator, just need the finer points.