I have a Volvo BL70 and its new to me. Its a 2003 and it runs great and appears to be very well taken care of. It has about 3500 hours on it. I have only run it about 10 hours but it has shut off on me twice and has had to crank and crank and crank to restart. Every time I start it cold it fires RIGHT up. Every time I've had to start it hot, its had to crank and crank and it seems to be lacking fuel. What seems to help is if I pull the hand throttle to full fuel or push the fuel petal in to full fuel it begins to spit and sputter then starts. I've changed the fuel water separator and the fuel filter. No change. I notice a small lack of power once hot and a slightly lower RPM. Someone who works on diesels told me it sound like it isn't advancing the timing when hot but I can't seem to find any info on that or even if my backhoe has that on the engine. Any help would be great....
I would check fuel return line from injector pump to fuel tank, if it is plastic and something is on it may close off when gets hot
Check your engine oil.. From what I gather, they are single unit injectors.. & the only thing keeping the inlet fuel from the return fuel is a couple of orings.. IF the orings get hard from the heat, u wont get the pressure required to lite it off.. So check the oil & see if its diluted..
Thanks thepumpguysc! You might have something there. I won't be able to check till tonight but I know when I was looking to purchase the machine, the engine oil was HIGH. I can't say it looked diluted but high. I will check when I get home. Are injection pumps hard to rebuild or are you saying its the injectors themselves? Either way, is it a "master" level repair?
Not knowing your wrench turning abilities.. I'll leave that up to u.. BUT it looks like its do-able.. I wouldn't condemn the pumps right away..I'd try to get an oring kit 1st.. especially if it starts right up, cold.. You'll probably have to call a fuel shop for the oring installation kits.. To bad u couldn't do a diagnostic test to confirm it.. Like using a gauge/set-up for a leak down test.. & block the return fuel somehow.. Add 25psi & shut off the gauge & watch for a pressure drop.. But I guess the old finger test for diluted oil will have to do.. Good luck
Whelp I thought I knew it but I’m still not sure. The oil level was perfect, not high, and I couldn’t really tell that there was oil in it. It felt and smelled very normal. I’m gonna change it tomorrow just cause I haven’t yet. I looked at the return line and it’s pretty straight, nothing pushing on it and it’s fairly durable. Any tests or suggestions?
I'm guessing this has mechanical injectors? Have you tried loosening a fuel line near the injector, and crank to see if you're getting fuel? Maybe a fuel shutoff solenoid is going bad when hot?
This or the wiring feeding the solenoid has problems. I had a no crank when hot and it was a bad connection on the wire feeding the 12+ to the solenoid.
IDK the shut off set-up but,.. it would make sense to remove the solenoid all together, to test the theory.
Ok so I’m finally back at it. I’ve used this thing several time during the winter but not for long. I got a bit of help from and expert from Volvo locally and what appears to be happening is my suction line is slowly blocking. Last night when it shut off after about an hour of running, the primer bulb was completely sucked fast and I was out of fuel in the system. The tank was over 1/2. I waited two hours and pumped the bulb and it would pump but very slowly and would return slowly. It started then but didn’t run well. I then opened the cap up and the bulb didn’t release so the suction line between the first water separator and the tank must be linked our clogged. Any idea what the best way to unclog that is and it’s probably rust so what the best way to clean all the crud in the tank? Thanks, Matt
Is the suction line rubber or steel?
It’s like a preformed hard rubber
I have seen rubber line that looks good on the outside be deteriorating on the inside and create a 'check valve' type effect. Try replacing the questionable section of line, even if is just with something temporary for testing purposes.
Do the filters show rust and contaminates collecting?? Adding a glass bowl prefilter may help to monitor the amount of dirt coming from tank. See link. Tank should have a drain plug, drain and flush if needed. https://www.ebay.com/itm/Fuel-Filte...197215?hash=item3b43f4f41f:g:rWwAAOSwSkpeVPzS
The water separator was full of rust when I changed it back in the fall. I hardly have any hours on it since then. Problem has been very consistent. I plan on dropping the tank, pulling the sending and pickup unit and blowing the line out with air to see what I get if anything. Also drain and clean the tank while I do all that!
Update... I drained the tank and it didn’t look too bad, WAY better than I thought it would. I disconnected the line at the water separator and blew it back into the tank. Nothing of note came out. I took the water separator off and blew the input out of there but I really didn’t monitor what came out. I then drilled some holes in the plastic of the fuel tank lid. I drove it around and used it for about two hours under heavy load and I kept getting out and looking for a vacuum and I might have solved the issue here! Thanks to everyone who helped.... I will let you know if the gremlins return.