No start frustrations.

[wayne pick]

Did you fill the spin on fuel filter to the top with fuel? Did you finally get all the air bled from the injectors? Did you "run" the engine on whatever "spray" you're using to re charge the batteries? You have to start from square one with fully charged batteries and bleed the system properly. STOP spraying whatever it is you are using to start the engine. No1, you can severely damage the engine. No2, It's not the right way to start the engine. Chances are you don't need a new IP, it ran fine untill you did the spin on mod, right?

 

[MyAngry85]

As I have stated before in this thread, my spin on filter has a hand pump, so yes it's full. How can there be air in the injectors if the truck runs just fine? Batteries are charged, and the system has been bled. I understand the risks of using starting aids, but the miniscule amount of spray I have used doesn't worry me. Half a second starts the truck right up, smoothly. But anyway, again as stated in the thread, the spin-on mod was just a means to eliminate the possibility of the old filter style being the cause of the starting issues.

 

[wayne pick]

Ok, there must be a restriction somewhere along the fuel lines or there may be some crud plugging the filter sock in the tank. Seems like the fuel pump is only delivering enough pressure to the IP when the truck is running. The new fuel pump may also be NG, it happens. You can disconnect the fuel line on the pump an see if it's making pressure when cranking the engine. Make sure to disconnect the purple wire to the IP when you test the pump. You can try putting an electric fuel pump on it, the airtex pump goes for about $40.00.

 

[MyAngry85]

The new fuel pump is good, I tested it per the TM's.

 

[saddamsnightmare]

September 22nd, 2012.

AH! The joy of driving a 37 year old GM product with minimal factory support! Could it be that the in tank fuel pump, if it has one is shot? On my deuce it ran good untill I lost prime...That's when we found that the IP was pumping the fuel, not the in tank pump.

The high probability is that you are loosing prime due to a miniscule air leak in the fuel lines. The best solution would be to craft a complete set of new fuel lines from the tank to the injectors as your truck may be wobbling along on its original fuel lines. Remember, rubber does deteriorate after 30 years or so, also any original plastic components also....

Remember, even under the best conditions it is 37 years old, and has probably sat a lot, and worse, been driven by a bunch of young GI's who drove it like they stole it....
My 49 year old gas Mercedes Benz Unimog has the occassional bad day, and the MB engineers were light years ahead of the GM ones, so patience and a little time and lots of $$$$$ will set your truck straight.

 

[wayne pick]

How many miles on the truck?

 

[JGBallew]

Any last words before I just order a new IP?

This is a last ditch method - Act accordingly.

Clean the outside of the IP, then pull the top cover. make sure there's fuel in it's sump and that it's clean in there.

Try starting. If it starts, it will make a bit of a mess, but you then know that the IP is doing it's job.

I'm going to bet your lift pump is sucking wind or losing it's prime though.

 

[wayne pick]

Check the rubber fuel lines from the sender to the steel lines on the crossmember under the cab. They can get brittle and crack, usually where they are clamped to the steel lines. Be a shame to spend $$$ on an IP if it turns out these are sucking air.

 

[MyAngry85]

I replaced the rubber lines between the filter and IP. I ran a line from the fuel pump to a can of fuel bled the lines and still no luck. That eliminated issues from the fuel pump to the tank. The truck has 36,000 miles, pretty positive that's accurate based on the shape of the vehicle inside and out. The motor has, it has a tag from 95 if I remember correctly, the entire engine and all its exterior parts were painted carc green. I'll have to look into the last ditch idea JG.

 

[MyAngry85]

This is a last ditch method - Act accordingly.

Clean the outside of the IP, then pull the top cover. make sure there's fuel in it's sump and that it's clean in there.

Try starting. If it starts, it will make a bit of a mess, but you then know that the IP is doing it's job.

I'm going to bet your lift pump is sucking wind or losing it's prime though.

So your saying to pour some fuel in the sump leave the cover off and try to start?

 

[trukhead]

is there a fuel filter or filter sock on the end of the pickup tube in the fuel tank? Could the pickup be collapsing with a fuel draw and expanding after the engine quits. Install a little fuel tank and filter on the intake of the engine lift pump and ascertain you have a working fuel system from the lift pump to the injectors and work backwards.
Is the hose from the lift pump to the filter in good condition and correct and is the line from the filter to the IP ok as well and what about the return line?
opcorn:

 

[MyAngry85]

is there a fuel filter or filter sock on the end of the pickup tube in the fuel tank? Could the pickup be collapsing with a fuel draw and expanding after the engine quits. Install a little fuel tank and filter on the intake of the engine lift pump and ascertain you have a working fuel system from the lift pump to the injectors and work backwards.
Is the hose from the lift pump to the filter in good condition and correct and is the line from the filter to the IP ok as well and what about the return line?
opcorn:

Already did all that.

 

[JGBallew]

So your saying to pour some fuel in the sump leave the cover off and try to start?[/QUOTE

If you pull the top cover and there's no fuel in the sump, then you have a supply issue. Check the lift pump and plumbing.


Pulling the cover bypasses the CO solenoid and the CA solenoid, and lets you see if there's any funk in there.

I've had one apart that looked like it had a melted tootsie roll in the sump.

 

[MyAngry85]

I pulled the cover off the IP today and it was full of fuel and very clean and in order...

 

[JGBallew]

I pulled the cover off the IP today and it was full of fuel and very clean and in order...

Did you try starting with the cover removed?

 

[MyAngry85]

How would that work? Wouldn't it be the same as trying to start it with the pink wire removed? and wouldn't it make a giant mess everywhere?

 

[JGBallew]

How would that work? Wouldn't it be the same as trying to start it with the pink wire removed? and wouldn't it make a giant mess everywhere?

You're removing what the pink wire operates, and the pump now has only the throttle as control. You'd have to shut it off by using a screwdriver to move the cutoff lever normally actuated by the solenoid.

And yes it make a bit of a mess, like I said earlier. But if it starts with the cover removed, your CO solenoid is probably stuck or dead.

Again, you were about to spring for a new IP. This is a last ditch method for testing the IP, as I mentioned earlier.

 

[MyAngry85]

I get what you're saying, just making sure. Wouldn't I be able to check the solenoid by turning the key on and touching the the wire to the terminal?

 

[JGBallew]

I get what you're saying, just making sure. Wouldn't I be able to check the solenoid by turning the key on and touching the the wire to the terminal?

No, I've had some where it clicks, but is not moving far enough to allow operation.

 

[MyAngry85]

Ah gotchya. Now if that solenoid was bad wouldn't the truck not start at all?