kawi600

Anyone with a similar setup that can tell me where you tapped the fuel after the filter to hook up the sender? All the docs I can find pertain to the 98+ which had the weak lift pumps

infidel

To check fuel pressure on 12 valve:

I drill and tap the top of the injection pump banjo bolt to 1/8'' pipe
thread, then install a male x female 1/8'' needle valve with 1/8'' tubing
compression fitting in it. Boost gauge or oil pressure tubing pushed
though some 1/4'' tubing to protect against cuts and kinks to the gauge.
For a gauge you can use a fuel, boost or water pressure gauge, for a 12
valve it must be at least 40 psi, 60 is ideal. I use rear connected, liquid filled,
stainless water pressure gauges and make my own mount. They have no
lighting but it's not a gauge you need to look at all the time. They can
be mounted low for the same reason. Use no Teflon tape, it doesn't work
with diesel. Instead use anti-seize or Permatex #2. Remember you are
working on the clean side of the filter, keep everything spotless.

Compression fittings with a ferrule that slips over the tubing will leak
if overtightened, finger tight with one half turn of a wrench is plenty.
The ferrule should be replaced if the fitting is ever removed.

If you can tap your manifold for a pyro tapping the banjo bolt is a piece
of cake. Just drill from the inside to keep the hole straight and tap from
the outside. You can also connect to the bleed screw on top of your fuel
filter with the appropriate adapter to tubing if you don't want to tap.
The adaptor is available from TST for $25 they say it is only for temporary use though http://www.tstproducts.com/service_tools_trial.htm .

After the install start your engine with the needle valve closed then open it slowly till someone in
the cab signals you that it's just reading pressure. If you tighten down
the packing nut under the valve handle the setting can't move. The valve
will control pulsation and buzzing and can also be shut down in the
unlikely event that you have a leak. Without a valve to restrict the flow
the gauge will pulsate so badly that you won't be able to read it in the
short time before it self destructs.

Parts list; 1/8'' needle valve - $2.50 from the hardware store, plastic
oil pressure tubing kit that comes with the compression fittings - under $10
from an auto parts store. 1/4'' tubing for protective sleeve - less than $2.
Gauge is your choice and may come with tubing. The water pressure gauges I
use cost less than $10, bringing the total cost to less than $25 and a
couple hours of your time.

I have several gauges that have been in service for over 7 years with zero
problems though you may have to occasionally close the needle valve a bit
more if the gauge starts pulsating.

Needle valve installed on inlet banjo bolt

kawi600

Ok, I got all the stuff and installed it. Bled the air out of the sender and the line by letting fluid from the pump push it out.
Question I have is how much pressure should I be seeing there? The gauge gives no reading at all despite all the pulsing that the gauge gets with the needle fully open.
Should I see pressure there even if the lift pump is dead?

infidel

You should see 18 psi minimum at idle and 25-35 at WOT.
Your 12 valve will run without a functioning lift pump but will lack power.
Also since you took the banjo out to install the gauge you you would have broke suction from the injection pump, if the lift pump was bad you never would be able to get it started.
Air in the gauge line makes no difference at all.

You say sender, this indicates you are using an electric gauge, a few things could cause it not to read.
1) Bad ground to the sender
2) Totally shot overflow valve, highly doubt it would cause the gauge to read zero though.
3) Sender was instantly destroyed by pulsations. I have one die in less than 30 seconds due to pulsations. Two more senders died in less than 1000 miles even with a needle valve to dampen the pulses before I decided to go to a mechanical gauge with fuel in the cab.
No problems for seven years with that setup.

Vulcan

Or you can just screw in a tapped banjo bolt for a 24v in the FF outlet.

kawi600

Hmmm.. ok so the fact Im getting the air purged after allowing it in means the lift pump isnt totally dead. I was almost hoping it was a dead lift pump. this truck has been lacking power since I got it.. Ive added the mods and its where Id guess it would have been stock.
when I took a resistance measurement of the sender while playing with the needle valve I didnt see much change so I think the sender was a DOA. I started with it off and gradually increased the flow of fuel.
Ill look into the overflow valve. The truck is going into a local shop next week I might ask them to check the fuel pressure and install a GS3K (its cold up here and I dont have a garage).
when I cracked the lines to bleed the air out I noticed the fuel didnt spray very hard from the fitting.. this should have had 15psi or so behind it? wonder if there is a restriction someplace.
I cleaned the strainer in the tank and replaced the fuel filter already.

TRCM

it won't spray out unless the fitting is very lose. Even under 15 psi, it still has to make it past the threads.