no fuel from ip? - PeachParts Mercedes-Benz Forum

adamkat22 · #1 07-30-2013, 09:47 AM

yesterday i lost power in my '82 300td. I changed the spin-on fuel filter and bypassed the primary filter. couldn't get it to start. starter seems sluggish so maybe thats my problem but i also noticed today that i can't get fuel out of the injector that is second from the firewall. originally i cracked them all at the injectors and they all bled. today i cracked them all where they come out of the ip and the 2nd from the firewall won't get wet after cranking the starter a few times. could that be the problem?

p.s. probably worth mentioning that i run wvo/diesel mix in the car just to throw that variable in.

barry12345 · #2 07-30-2013, 12:26 PM

See what fuel pressure and volume is present from the lift pump. Sounds like you have fuel starvation.

Diesel911 · #3 07-30-2013, 01:03 PM

Get some Extra 5/16" ID Fuel Hose and run that to something like of those 2.5 liter Fuel Cans full of Diesel Fuel.

Get on the Hand Primer and pump it until you hear a buzzing sound from the Fuel Pressure Relief/Overflow Valve and then pump it some more maybe 25 times.
Loosen the Fuel Injection Line Nuts at the Injectors and crank and see if you are getting Fuel there.
If so tighten the Nuts and attempt to start.

The above obviously bypasses all of the Fuel lines and Tanks to the Rear. If it works something to the rear is plugged up.
If it does not work try changing the Fuel Filters again and repeat the Hand Primer Pumping even if you fill the Spin-on Filter with Fuel.
You could also do the bleeding at the Injectors again to get any Air out of the lines quickly.

If that does not work you are looking at an issue with the Fuel Supply/Lift Pump or some other no start issue like the Glow Plugs not working or Vacuum is still holding the Shutoff Valve on the IP in the shutoff Position.

whunter · #4 07-30-2013, 01:30 PM

Quote:

Originally Posted by adamkat22

yesterday i lost power in my '82 300td. I changed the spin-on fuel filter and bypassed the primary filter. couldn't get it to start. starter seems sluggish so maybe thats my problem but i also noticed today that i can't get fuel out of the injector that is second from the firewall. originally i cracked them all at the injectors and they all bled. today i cracked them all where they come out of the ip and the 2nd from the firewall won't get wet after cranking the starter a few times. could that be the problem?

p.s. probably worth mentioning that i run wvo/diesel mix in the car just to throw that variable in.

Did you pre-fill the fuel filter ???

If the answer is NO, the injection pump will take an incredibly long time to clear the air.

.

adamkat22 · #5 07-30-2013, 06:20 PM

fuel filter was filled. went to prime the pump (didn't know about the buzzing that should occur...never did that with my 240) and after a while fuel started coming out of it. guess that needs to be replaced. maybe i'm sucking air from there? guess i should mention that i had also tried a gasoline soaked rag over the intake and that wasn't getting much more than a tiny cough so maybe air intrusion. i'll fix priming pump and let you know. thanks

cooljjay · #6 07-30-2013, 06:38 PM

Quote:

Originally Posted by adamkat22

p.s. probably worth mentioning that i run wvo/diesel mix in the car just to throw that variable in.

I am guessing no one else noticed this PS?

You have a clog somewhere....10-1 its the fuel tank strainer....you may have even killed the lift pump...

You can but technical you cannot mix diesel and wvo and expect the car to run....if it was bio...thats even worse!

Using wvo, you really need a 2 tank system...you start on diesel and when the wvo is warm enough you toggle over....now when your almost done with you trip....you toggle back to diesel to purge the system of wvo...

First you need to clean the tank and screen....then working on un jelling the fuel system....if your injectors are froze....you'll never get enough spray to run the engine and they should be replace...

Diesel911 · #7 07-30-2013, 06:56 PM

Quote:

Originally Posted by adamkat22

fuel filter was filled. went to prime the pump (didn't know about the buzzing that should occur...never did that with my 240) and after a while fuel started coming out of it. guess that needs to be replaced. maybe i'm sucking air from there? guess i should mention that i had also tried a gasoline soaked rag over the intake and that wasn't getting much more than a tiny cough so maybe air intrusion. i'll fix priming pump and let you know. thanks

The buzzing or squeaking sound might not show up with the thicker WVO.

adamkat22 · #8 07-31-2013, 10:45 AM

i have done full wvo conversions on my other cars, but the previous owner of this vehicle (as well as some other folks in the area) do the old 'wvo straight into the stock tank' move, so i was rolling with it for a little bit as my own personal experiment (for what its worth there is a heat wrap around the stock fuel filter). have plans to do the full conversion soon. anyways, thats all getting into a discussion that probably belongs in 'alternative fuels'.

ordered a new primer pump (since that obviously is broken (and possibly letting air in?). looks like i need a special tool to do the tank strainer so i'll do that next and then see where its all at. i can get the injectors wet and i have a vacuum pump that didn't register anythign wrong (ie clogged tank strainer) so i'm going to move foward with air leak issues first and let you all know how it goes. thanks

adamkat22 · #9 07-31-2013, 11:41 AM

realized i had a primer pump from my old 240D so i put that on and pumped away. fuel still came out from the pump but eventually i heard a squeaking (maybe the buzzing that was talked about earlier in the thread) and the car fired right up on the second try (with the help of a gas rag near the intake). its possible i never pumped long enough. i still have two questions though:

1. i assume that the primer pumps are not supposed to leak fuel out when you prime them? i'll still put in a new one (also i didn't have a new crush washer when i installed the one i picked off my old engine). could a leaking primer pump have caused me to lose power the other day?

2. if it was actually a fuel starvation problem then i guess i'm confused about my vacuum gauge. i have a sun-pro vacuum-boost gauge that i installed between the filter and the IP a few weeks ago so i would knwo when it was time to change filters. it never registered more than a few bars of boost. today i put a clamp on the fuel line and slowly tightened it as i revved the engine. the vacuum gauge seemed to register on the 'boost' side as i tightened the clamp (i thought that a clogged filter should register on the 'vacuum' side, but maybe i'm confused about boost vs. vacuum?). if i had a clogged fuel filter or clogged tank strainer shouldn't it have shown up on my gauge?
thanks

toomany MBZ · #10 07-31-2013, 12:47 PM

1. No and maybe.

2. Are measuring fuel pressure?

scottmcphee · #11 07-31-2013, 01:32 PM

That element in the IP might be damaged and never worked in the first place since before your incident. But your car should then "run like it used to", and I think all 5 and 6 cylinder MB's could run on one less cylinder firing. Getting it started would be like starting on one bad glow plug, possible but a bit clunky.