sixwongs

Filled van with gas, drove home . Tried starting van later.
Van will crank but not start.
I have sprayed starting fluid in air intake, van starts runs a few seconds, then quits.

Any ideas what to check first, read posts on fuel pumps and pressures , relays, how to do check pressure?

MT-2500

Go easy on starting fluid.
A lot safer to use carb cleaner.
How low are you running it before fill up?
Check for fuel pressure and the right amount of pressure.
Borrow or rent or by a fuel pressure gauge to check fuel pressure.
What engine?
If fuel pump not running check the fuel pump plug in wiring at transmission crossmember.

__________________
Remember proper testing gives us the answer to many problems.
MT

sixwongs

usually fill the gas tank 1/4 from empty.
The engine is a 5.7 v-8 vortec.
to save me time searching is this fuel pump plug in wiring at transmission crossmember, is this located at the front or rear of van?
thanks for the tip on carb cleaner will try that next if needed .
I had a helper turning the key to the on position, while I was on the outside of the van listening.
We both heard a "hum" for a few seconds.
We did that few times, then the helper tried starting the van.
The van started 3x in a row and then it did not start.
Also we did not hear the "hum" during the failed attempts.

MT-2500

The hum is the fuel pump running.
It should run for 2 seconds when key is first turned on.
Or when the engine is cranking or running.

12 volt power to the fuel pump is supplied on the gray wire going to the fuel pump from relay in underhood relay fuse box.

Find the gray wire going to fuel pump tank unit.
And check for 12 volts on it key on prime or engine crank.
If no 12 volts on it jumper it with a 12 volt fused jumper and see if pump runs.
Follow the wires from the tank back to the engine and look for a 4 wire plug in on the engine/transmission cross member.
Not sure about a 1500 but on a 3500 it is a problem child.
Also when no pump run check for spark to plugs.
No spark can also cause no fuel pump run.

__________________
Remember proper testing gives us the answer to many problems.
MT

sixwongs

Decided to drop the fuel tank and put new fuel pump/fuel sending unit.
Been having trouble with gas gauge for quite a while.
So I'm thinking this might take of both problems.

I got the tank down about 4 inches, have it on a couple of jacks.
Having a little trouble disconnecting the fuel lines and electrical connectors.
There must be an easier technique than fingers?
As I keep dropping the tank will I run into any other problems?
just don't want to break any fuel lines, wires, etc
any tips?

Thanks

MT-2500

Just take your time and get all fuel lines and wires unplugged.
Watch for vent hoses and stuff on ends of tank to.
I always like to unbolt filler pipe where it goes onto the bed and leave the filler hose on the tank.
Remember there is a small hose inside the big hose.
Also better to replace it with with a Delphi or AC Delco fuel pump module.
Good luck
MT

__________________
Remember proper testing gives us the answer to many problems.
MT

sixwongs

I have the fuel tank on the ground.
I worked the fuel pump/ fuel level level sensor assy out from the top of the tank.
The assy has a thick O-ring to seal the pump to the tank.
Is there a easy method to slide the new pump assy and O-ring back into the tank?

Thanks

MT-2500

I always put the big O ring in the tank grove and then feed the fuel tank module/assembley in to the tank.
Watch and do not bent or catch the float.
Just twist pump around and work it in.
When pump and float is in watch and get the pump turned right.
There should be a arrow or notch for it to center it.
Then push the pump straight down and install lock ring.
Also look in the new fuel pump box.
There may be some installation instructions in there.
Good luck
MT

__________________
Remember proper testing gives us the answer to many problems.
MT

sixwongs

Finished the job on sept on sept 2nd. thanks for the advice.

Here are some notes on the job:

1) I found out I did not need to disconnect the fuel line and electrical connectors at the top of the fuel pump.

2) Had to drop the gas tank slightly to disconnect the fuel tank filler hose to
siphon the fuel tank.

3) My most time consuming parts of the job were siphoning, trying to get the the electrical connector off the switch(found a wedge had to be
removed). I dropped the fuel tank and pulled the tank from under the
van and pulled the wedge out and The last thing, I spent a lot of time
on was the installation of pushing the fuel pump assy. into the gas tank.
I eventually put some vasaline on the large ring and used a small screw
driver and worked the assy. and ring together into the opening.

4) When the tank is the ground you can disconnect fuel line hoses and
electrical connectors from front of the tank.

Thanks again for the help.

MT-2500

You are welcome.
And
Thanks for posting back how it went.
Glad you got it in and going good.
MT

__________________
Remember proper testing gives us the answer to many problems.
MT

indyrt

my 3500 has had issues... in summer it would not want to keep running when cold. The problem came and went. It has 170k on it and I run low on fuel all the time... I heard about the low fuel issues and pupm probs... at one poiont , it was leaning out to detonate under load.. I changed the fuel pump and it was better then went away completly.... It came back after a rain along with my speedo freaking out. I think that was / is the computer getting wet. Changed the computer to fix trans / gauge prob... Now, it is really cold and will not keep running. It fires and quits. Wait... fires and quits....over and over. Not getting continual fuel... I'm going to try the old computer first. Than fuel psi and the pinch off trick. Ironically, i was once again about out of fuel when i parked it.... hum.....My guess is pump is/ was/ has gone bad.... .... ....


Thanks for the help!!!

RT

MT-2500

Proper testing not throwing parts at it.
This post is old and was started by someone else.
Always check the date on a post before replying and if you have a problem of your own hit the new thread button and startr you own post and someone will help you.
MT

__________________
Remember proper testing gives us the answer to many problems.
MT