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  #16  
Old 03-27-2008, 02:53 PM
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Brian,

Thanks for the ideas.

See pic below. I had a extra banjo which I capped off and installed on the filter so that fuel does not squirt out doing the test. The banjo removed is the returns for the IP and injectors and when I cranked, no fuel came out.

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Last edited by Brian Carlton; 03-27-2008 at 03:02 PM.
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  #17  
Old 03-27-2008, 03:04 PM
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Originally Posted by funola View Post
Brian,

Thanks for the ideas.

See pic below. I had a extra banjo which I capped off and installed on the filter so that fuel does not squirt out doing the test. The banjo removed is the returns for the IP and injectors and when I cranked, no fuel came out.
Steve,

Did you try to get fuel from the line that goes from the pump to the filter? That's the line you want to test.
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  #18  
Old 03-27-2008, 03:24 PM
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Now I'm wondering which pump you meant. Inj pump or lift pump? I think you want me to test the lift pump? That makes sense.

I aslo took the fuel shutoff solenoid out and it was not stuck. Pic below is the way it came out. With a Mightyvac on it, it retracted.

I took a compression reading alsoand all cylinders are 320 psi (cold obviously) except the one closest to the firewall which was at 380 (is that cyl 1 or 4?)

What is the easiest way to determine if the inj pump is actually turning? I understand it is driven off the vac pump gear through a dowel? Is there anyway to check w/o removing the vac pump (which is ok btw)?

Before I forget, there was a bit of black stuff on the banjo return fitting which is either algae or bacteria? I wonder if it is blocking some passages in the IP? There is a small banjo fitting on the IP near the lift pump which I believe is the lube for the IP. I will take that off and see if oil squirts out to rule out IP lube starvation.
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85 300D turbo pristine w 157k when purchased 161K now
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Last edited by funola; 03-27-2008 at 06:31 PM.
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  #19  
Old 03-27-2008, 03:41 PM
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Originally Posted by funola View Post
Now I'm wondering which pump you meant. Inj pump or lift pump? I think you want me to test the lift pump? That makes sense.
Lift pump.
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  #20  
Old 03-27-2008, 04:12 PM
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Originally Posted by Brian Carlton View Post
Lift pump.
Damm! I guess I have a habit of fearing the worst and too focused it was the IP lol. I'll go check the LP output later.
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  #21  
Old 03-27-2008, 04:18 PM
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Damm! I guess I have a habit of fearing the worst and too focused it was the IP lol. I'll go check the LP output later.
You've got to start at the lift pump. No pressure from that pump means no fuel to the IP. If the IP has fuel..........and no air..........it will deliver it to the injectors.

Furthermore, the IP doesn't just stop sending fuel to the injectors unless it suffers a catastropic internal failure..........and, to my knowledge..........that doesn't ever happen.
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  #22  
Old 03-27-2008, 05:06 PM
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There is fuel from the LP, approx 3 oz in 15 seconds. There's lube oil pressure at the IP. What's next?

Quote:
Originally Posted by Brian Carlton View Post
You've got to start at the lift pump. No pressure from that pump means no fuel to the IP. If the IP has fuel..........and no air..........it will deliver it to the injectors.

Furthermore, the IP doesn't just stop sending fuel to the injectors unless it suffers a catastropic internal failure..........and, to my knowledge..........that doesn't ever happen.
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  #23  
Old 03-27-2008, 05:17 PM
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Fuel filter has less than 400 miles on it.
Time to drop it and take a look. I'd replace it just to be sure.

I've been tricked before by the fuel filter...........
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  #24  
Old 03-27-2008, 05:29 PM
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A new secondary fuel filter was put it yesterday. Zero miles on it Primary filter is nice and clean w less than 400 miles. What next?

Is there an online blog on rebuilding the 4 cyl inline Bosch IP?

Quote:
Originally Posted by Brian Carlton View Post
Time to drop it and take a look. I'd replace it just to be sure.

I've been tricked before by the fuel filter...........
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Last edited by funola; 03-27-2008 at 05:34 PM.
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  #25  
Old 03-27-2008, 05:34 PM
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A new secondary fuel filter was put it yesterday. Zero miles on it Primary filter is nice and clean w less than 400 miles. What next?

Is there an online blog on rebuilding the 4 cyl inline Bosch IP?
How many times did you pump the primer?
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  #26  
Old 03-27-2008, 05:36 PM
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About 50? Is that enough?
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  #27  
Old 03-27-2008, 05:44 PM
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About 50? Is that enough?
You'd think so, but I'd go a bit more.

You should hear the fuel escape via the return line at the secondary.

I've got a suspicion that you've got an air leak somewhere. Look for any fuel weeping anywhere on the lines from the lift pump to the secondary to the IP.
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  #28  
Old 03-27-2008, 05:48 PM
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Does he not need to crack the connection at the injector if he has air in the line ?
How is air going to get out when air pressure won't pop the injector ...?
I have to do this on the Ford tractor...
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  #29  
Old 03-27-2008, 06:10 PM
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Originally Posted by leathermang View Post
Does he not need to crack the connection at the injector if he has air in the line ?
How is air going to get out when air pressure won't pop the injector ...?
I have to do this on the Ford tractor...
See........now you made me go and check the FSM.

Yes, the "union screw" at the fuel fliter, which is the horizontal outlet line seen in the photo in post #16, should be cracked and the primer should be operated untl clear fuel emerges from the union screw.

Then, the screw is tightened and the primer pump is then operated until an audible rattling sound is heard at the IP bypass valve.

Additionally, the IP bypass valve can be the culprit here if it's allowing fuel to pass at lower than the specified pressure. In this situation, the fuel pump cannot build pressure to the IP. A quick test for this would be to clamp the return line from the bypass valve. If the engine starts immediately, the valve is the culprit.

Look at the photo in post #16. There is a brown fuel line that goes right over the top of the red dipstick. That line leads to the IP and the bypass valve. The bypass valve is the bolt that secures the banjo at the end of this line. If you can plug this line to see if the engine will start.........you can confirm if the bypass valve is NG.

Last edited by Brian Carlton; 03-27-2008 at 06:28 PM.
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  #30  
Old 03-27-2008, 06:43 PM
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That brown line that goes over the red dipstick handle is the clear hard nylon line that turned brown over the years. Isn't that aka the IP return which meet up with the injector return line and the cigar hose at the 3 way banjo? The nylon line cannot be crimped without damaging it. What if I take the config of photo in post #16 and add a bolt and washer to the hanging open banjo to close it off? Would that work to test the IP bypass valve?

Quote:
Originally Posted by Brian Carlton View Post
See........now you made me go and check the FSM.

Yes, the "union screw" at the fuel fliter, which is the horizontal outlet line seen in the photo in post #16, should be cracked and the primer should be operated untl clear fuel emerges from the union screw.

Then, the screw is tightened and the primer pump is then operated until an audible rattling sound is heard at the IP bypass valve.

Additionally, the IP bypass valve can be the culprit here if it's allowing fuel to pass at lower than the specified pressure. In this situation, the fuel pump cannot build pressure to the IP. A quick test for this would be to clamp the return line from the bypass valve. If the engine starts immediately, the valve is the culprit.

Look at the photo in post #16. There is a brown fuel line that goes right over the top of the red dipstick. That line leads to the IP and the bypass valve. The bypass valve is the bolt that secures the banjo at the end of this line. If you can plug this line to see if the engine will start.........you can confirm if the bypass valve is NG.
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83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked
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