air in diesel fuel 94 suburban

[nyvenom30]

hi im a new member. my name is brian. i just bought a 94 chev suburban k2500 diesel 246k miles. i have a few issues with the truck. biggest being that when i start it let warm up everything seems fine after about 20 to 30 minutes of idle, air starts bubbling up the water/filter seperator. The idle starts going up and down and the motor shuts off. After i let it sit with the key on the position, sends enough fuel to start up and run again for a little and the same thing happens and it shuts down. im gonna get a new fuel tank, sending unit, fuel lines, fuel pump, new filter for the after market water/filter, new tank straps. i figured with this kind mile on a truck like this i might as well replace all these components. im sure im missing a few things lol. yesterday i replaced the ignition switch on the steering column under the dash and now the truck wont shift out of first but park reverse and neutral work. for some reason wen i put it in over drvie or drive gear it wont shift out of first. i tried my best to line up the switch and the other thing that lines up with it. any help with this issue would be greatly appreciated.

 

[great white]

Check to make sure all the connections are proper on the ignition switch. Many many systems power through the switch and if a contact is loose on not proper lots of weird things will happen.

Since it was working before you changed the switch and not after, logic dictates that's where your problem lays.

Air in the filter manager means it's sucking in air somewhere downstream. Rusted lines, cracked rubber, etc. You plan to replace all that stuff so no sense even chasing anything until you replace it all. The tank lines are particularly a PITA as they rust and get pin holes....

 

[nyvenom30]

i will double check over connections at the switch what is the part mounted with it on the side of the column? as for the sending unit and the pump. my vin has an f in it. does this mean i need a pump that matches that cause some sites indicate that it matters and im not sure. im trying to connect them and get answer. so will see. i just purchased new fuel lines on ebay for $99 and i found the 42 gallon tank for 147 shipped. the sender unit is on partsgeek.com but im not sure which one to get and the fuel lifter pump external mount, they have the tank straps aswell.

 

[great white]

i will double check over connections at the switch what is the part mounted with it on the side of the column? as for the sending unit and the pump. my vin has an f in it. does this mean i need a pump that matches that cause some sites indicate that it matters and im not sure. im trying to connect them and get answer. so will see. i just purchased new fuel lines on ebay for $99 and i found the 42 gallon tank for 147 shipped. the sender unit is on partsgeek.com but im not sure which one to get and the fuel lifter pump external mount, they have the tank straps aswell.

Well, just get a 98+ lift pump if you're going stock. They have a slightly higher flow rate and a bit more robust than the older model pumps. Truthfully, all the OEM lift pumps suck. But Post 98 is better.

The "F" only means you don't have emissions controls. Makes no difference to the Injection pump, Ergo: no real difference to the lift pump. The difference in the couple HP is in the PCM.

You want the diesel sender/pickup assembly. A gasser pickup will not work.

 

[someotherguy]

The smaller switch on the column opposite the ignition switch, is the high/low beam switch. If this is the ore you're talking about - blue plastic socket in this particular example:

You must be registered for see images attach

Richard

 

[nyvenom30]

thats the part. the one on my truck looks a little different. thanks for posting that.
something i realized today is that when i bought the truck the fuel tank cap wasn't tightened all the way and when i put diesel in it i tightened down all the way the first night i drove it this problem seemed to instantly start. any clue on where the fuel tank vent solenoid is located?
if the stock pumps suck what should i use instead. is the dahl/baldwin diesel filter/ water separator model 65 good for this truck?

 

[4thesporty]

i found the 42 gallon tank for 147 shipped. .

Where did you find this?

 

[great white]

thats the part. the one on my truck looks a little different. thanks for posting that.
something i realized today is that when i bought the truck the fuel tank cap wasn't tightened all the way and when i put diesel in it i tightened down all the way the first night i drove it this problem seemed to instantly start. any clue on where the fuel tank vent solenoid is located?
if the stock pumps suck what should i use instead. is the dahl/baldwin diesel filter/ water separator model 65 good for this truck?

The diesel cap is different from the gasser cap. The gasser will hold too much vacuum on the tank. No air in = no fuel out. It won't make for air in the lines though. It might "speed up" a small bleed into the fuel system as the lift pump/injection pump put more pull on the system, but you will still have to find and fix the "bleed".

The tank "vents" through the fuel cap. There is no "solenoid".

Most guys use a walbro fuel pump in place of the OEM one. I went "whole hog" stepped up to a raptor 100 lift pump with 1/2" eaton pushlok from tank to filter manager and a 30 micron prefilter assembly.

My refilter came from a volvo FM12 MD57. I chose it because it uses a 12" filter, clear fuel bowl, WIF indicator, has fuel preheating and a built in manual priming pump instead of the racor "push bulb" primer.

My fuel system bit me for about 700 bucks all in and I still have to replace the fuel pickup with something a little better (IE: bigger tube) to take advantage of it all.

If you want to know if a filter is good for the truck, the two main things you have to look for is if it will flow enough GPM and the filtration. If going with just a single racor, you need to get down to at least 5 mirons.

 

[nyvenom30]

ebay.com for the fuel tank but partsgeek.com had it for a near same price. i got it from them cause i ordered a bunch of other stuff, got free shipping and 15 bucks off. so i got everything i needed for 325.

sounds like u have a very nice fuel set up.

i got these fuel lines for 100 bucks hope there correct. http://www.ebay.com/itm/271300810258?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

the new sending units have socks on them i read that u should take this off before inserting in the new tank.

the dahl model 65 has a 30 micron filter in it and can flow 20gph more specs in link. but its mounted on the firewall under the hood, in the wrong place. its gotta be between the fuel tank and pump. so i gotta relocate it. not sure where i should put it, that will keep it safe.
http://www.baldwinfilter.com/literature/english/6 dahl/form4060.pdf

today i took the cap off the fuel tank and a bunch of air rushed into it. not sure if this is normal or not. i left the cap loose to see if it made a difference or not and no difference. i was able to start the truck let it run for 10 mins and drove it around the block and than came back to my house less than 2 miles of driving this happened. still got big air bubbles in the filter water separator. once the air bubbles start the truck idle hard and motor turns off. i have know clue where the bleed is ive been trying to find diagram on fuel layout for the truck but not having any luck.

i looked at the ignition which and the one plug wasnt pushed in all the way. truck shifts fine again.


the fuel lines and pump has been rigged up bad on this truck so it a mess compared to stock. lol. gonna be alot of sorting out what they did and correct it all. i cant even fine the stock filter manager yet. lol.

im currently trying to buy the service manual for the truck but having a hard time figuring out which one i need. i found a few on books4cars.com

 

[someotherguy]

Sure sounds like you have the incorrect (non-vented) cap, for a gas application. Or, a correct (vented) cap, that the vent valve is stuck closed.

Richard