Hard to start after injector pump belt replacement

[palmtree]

Well I finally found some time to trouble shoot the Volvo. Here's what I did:

I bought a primer bulb and installed it between the hard line and the filter. I used clear fuel line so I could see what was going on (look for air). I evacuated the air from the line so it attached to the filter head without any air in the line. I was not able to move the fuel with the bulb -- I simply couldn't squeeze hard enough. When I stopped trying to squeeze the bulb I had a bubble form where the clear line attached to the filter head. If I raised the bulb above the level of the filter then I would get another small bubble and then another and that would happen every 20 seconds or so (I'm not sure if this is expected or not - but I didn't expect it).

Next I evacuated the air from the clear hose with the bulb again and tried to start the car with the bulb installed. It would not start and the bulb did not collapse. The bubble appeared again and it did not move at all when the car was cranking.

Next I evacuated the air from the clear hose again and disconnected the other end of the hose from the hard line and submerged that end in a can of diesel (bypassing the car's tank and hard line). The outcome was the same. I could not hand pump the fuel and I could not start the car or collapse the bulb. The bubble that formed where the clear hose attached to the filter did not move at all.
Supposedly the previous owner had the IP rebuilt 8500 miles ago with the rest of the engine.

Any ideas? Also thanks to all for your help so far.

Brett

[v8volvo]

Hmmm...

It sounds like you may have an air lock in the injection pump or some kind of return flow blockage. You'll probably want to go through and fully bleed the system as a starting point, and move forward from there. Did you replace the fuel filter? If so, how did the old fuel look that came out of the one you took off? Any obvious crud in there?

Here is what I would do. Assuming you have a clean fuel filter installed, start by using a 10mm wrench to crack open the little bleeder screw on top of the filter head. Then, pump the primer bulb until you see steady flow of clean fuel with no air in it coming out of that bleeder. The bulb should pump easily. Then, close the bleeder, and using a 17mm or 19mm (forget which) socket wrench, crack open the banjo fitting at the upper end of the fuel supply line running from the filter head to the IP, at the point where it enters the IP inlet. Repeat the same bleeding procedure, pumping until you see no more bubbles in that clear line from filter to pump and fuel is flowing freely out of the line union. Carefully re-tighten the banjo fitting (tight but don't overdo it or the hollow banjo bolt can break). Now, you know that you have clean, air-free fuel supply all the way to the IP. Next, pressurize the IP by pumping the primer bulb until it is difficult to squeeze, and then, using a 17mm open-end wrench, crack open each of the 6 injector line union nuts at the fuel injectors. With you standing under the hood and continuing to squeeze the primer bulb and watching the motor, have a helper sit in the car, hold the accelerator to the floor, and crank the engine with the starter until you see steady repeated spurts of fuel coming out of each injector union. At this point, stop cranking, tighten up each of the injector line nuts, hose the engine down with water to wash the excess fuel off of everything, and fire it up. It should start almost immediately.

This will put you back at square one, with a primed injection system. The next step, after you get the car going, will be to drive it a bit and determine if/where/how/why it is continuing to lose prime and/or develop a fuel supply restriction.

Let us know how it goes.

[palmtree]

Thanks again for responding George.
Hopefully I can find some time this weekend to carry out your recommendations. Of course I have drained my battery charge with all the attempts to start the car -- so I'll need to get that charged up first.
I did notice that the fuel hose from the hard line to the filter looked pretty new but the fuel return hose looked really old. It doesn't seem like it would be a problem to introduce air into the hose on the return trip -- would it? The vaccuum hoses also look very old and have some seriouse cracks. Do the vaccuum hoses have anything to do with the fuel injection system (I wouldn't think so)? Any chance that they could be the culprit? I'm looking for easy/cheap fixes here . It looks like the fuel supply hose is 5/16" and the return hose is 1/4" -- is that right?

[v8volvo]

A leak at almost any location in a VE-pump diesel's fuel system can create a problem, since it can open up the possibility of fuel siphoning back to the tank through the supply line and air being admitted in through the leak in the return hose when the car is not running, causing a loss of prime. However, in your case, there's little chance that this is an issue... Unlike leaks in the inlet line, IP return line leaks will make themselves known with considerable external fuel leakage when the engine is running. On a Volvo particularly, even a small return line leak can make a very big mess in a very short time... ask how I found that out. If you do not have evidence of fuel leakage under the hood, your return lines are OK, even if they look old and tired.

Vacuum hoses also would not be a factor here, though if yours are in really bad shape you may want to replace them soon after you get the car back on the road, to avoid the possibility of a sudden loss of brake assist that could lead to an unsafe situation.

IIRC both the supply and return hoses are 1/4" ID, at least for a 700 series.... though now that I think about it, I think it may be the case that the 200 series cars did use 5/16" on the fuel inlet, as well as 1983 and some 1984 D24T 700's. Is your fuel filter head inlet attachment a straight fitting that points directly out towards the driver's inner fender, or is it a banjo fitting that points towads the rear of the car? If it is the straight fitting, it is 5/16"; if it has the banjo it is 1/4".

George