Mike Rancourt
Member
My fear: there’s some debris that got into the high pressure pump or some other component in there (see below, especially where I discuss “polymerization”). But maybe that’s way off target.
My simple question #1: Can a failing or debris-clogged high pressure pump lead to fuel restriction light and fuel pressure codes?
My simple question #2: assuming fuel filters and hoses are all new, which components from the low pressure pump up to the injectors could possibly cause fuel restriction light and fuel pressure codes such as P2007-1?
My complicated question: Which components might be failing and thus lead to the same fuel restriction conditions while running diesel AND running a second, separate WVO fuel system(see below), with the problem getting worse and worse over time (worse on WVO and only recently showing up on diesel)?
The van: 430k miles, 2002 om612 with two tank WVO conversion (pretty good custom kit with 2 mi filter, fuel temps between 180-250 F), also runs Diesel HPR (https://propelfuels.com/our_fuels?a...-xXS_g0nx9T5_XnN_p_hENVWZPbAYk4MaAqv8EALw_wcB) and used to run commercial biodiesel (https://choosesq.com/) in the stock tank.
The problem: there are likely two separate problems but maybe related for all I know.
Things I’ve done to address this problem or apparently related problems in the past year:
The big story you may not have time to read: In May 2019 while on a cross country trip, the van developed a stalling issue at highway speeds. The problem started out mostly while running WVO, but it also occurred while running diesel. I changed all filters, but basically it didn’t go away. I have an online fuel filter just before the low pressure pump to catch any crud (polymers) that might come off the WVO components, and it did seem to be catching a lot of stuff, so I cleaned it over and over again. Basically, I just had to drive carefully for the last 3000+ miles to get home. I made it home to San Diego and put in remanned injectors after marginal results on leakoff tests. I broke two hold down bolts (it was the torque wrench’s fault, I swear!) and kind of struggled with the time serts. None of this helped. I then installed a new fuel pressure solenoid which seemed to solve the problem, though the WVO system continued to have similar concerns. I replaced some suspect WVO components and found major issues with polymerization on brass fittings (the system now only has stainless steel and aluminum fittings, so no more polymerization). A few months later I had uneven idle problems that may not be related, but may be. I installed a new fuel pressure sensor which cleared it up for a few weeks. Then both the rough idle and the stalling on WVO got more irksome (maybe I just noticed them more). Finally, I started the van one morning last week and couldn’t get above, say, 20MPH running on diesel. I always suspected debris made it past that inline filter, so I took off the fuel lines to the low pressure pump and blew air (with a bicycle pump) to see if I could get anything to come out. Nothing did, but when I hooked it up again, there were no fuel restriction problems on diesel. Still problems when I switched over to WVO. A couple days later, it happened again. I took things apart again and put them back together, and it runs fine now on diesel, but for how long?
My simple question #1: Can a failing or debris-clogged high pressure pump lead to fuel restriction light and fuel pressure codes?
My simple question #2: assuming fuel filters and hoses are all new, which components from the low pressure pump up to the injectors could possibly cause fuel restriction light and fuel pressure codes such as P2007-1?
My complicated question: Which components might be failing and thus lead to the same fuel restriction conditions while running diesel AND running a second, separate WVO fuel system(see below), with the problem getting worse and worse over time (worse on WVO and only recently showing up on diesel)?
The van: 430k miles, 2002 om612 with two tank WVO conversion (pretty good custom kit with 2 mi filter, fuel temps between 180-250 F), also runs Diesel HPR (https://propelfuels.com/our_fuels?a...-xXS_g0nx9T5_XnN_p_hENVWZPbAYk4MaAqv8EALw_wcB) and used to run commercial biodiesel (https://choosesq.com/) in the stock tank.
The problem: there are likely two separate problems but maybe related for all I know.
- apparent fuel restriction problems
- uneven idle (air bubbles are present in diesel side but not in WVO)
- p2007-2, P2007-1 monitoring of predelivery pressure is too small
- Also once recently got P1187-8 rail pressure monitoring - pressure control valve jams in the closed position and P2006-2 predelivery pressure sensor - the signal voltage is too high. This was likely after I disconnected the fuel pressure sensor while running.
Things I’ve done to address this problem or apparently related problems in the past year:
- installed remanned injectors (did a horrible job https://sprinter-source.com/forums/index.php?threads/78167/#post-792981)
- Installed new fuel pressure solenoid (https://sprinter-source.com/forums/index.php?threads/28084/post-797849). When I did this, the fuel restriction and stalling issue went away for a while.
- Installed new fuel pressure sensor (https://sprinter-source.com/forums/index.php?threads/69841/#post-852100). When I did this, the rough idle went away for a while.
- Replaced o rings on fuel line to low pressure pump
- Installed new diesel and WVO filters
- I’ve also tried troubleshooting air bubbles in the diesel side by checking out tank venting issues. BTW, there’s a whoosh when I open the diesel fuel cap, but that’s just the diesel side. I know it’s possible the are coincidental restrictions on both diesel and WVO sides.
The big story you may not have time to read: In May 2019 while on a cross country trip, the van developed a stalling issue at highway speeds. The problem started out mostly while running WVO, but it also occurred while running diesel. I changed all filters, but basically it didn’t go away. I have an online fuel filter just before the low pressure pump to catch any crud (polymers) that might come off the WVO components, and it did seem to be catching a lot of stuff, so I cleaned it over and over again. Basically, I just had to drive carefully for the last 3000+ miles to get home. I made it home to San Diego and put in remanned injectors after marginal results on leakoff tests. I broke two hold down bolts (it was the torque wrench’s fault, I swear!) and kind of struggled with the time serts. None of this helped. I then installed a new fuel pressure solenoid which seemed to solve the problem, though the WVO system continued to have similar concerns. I replaced some suspect WVO components and found major issues with polymerization on brass fittings (the system now only has stainless steel and aluminum fittings, so no more polymerization). A few months later I had uneven idle problems that may not be related, but may be. I installed a new fuel pressure sensor which cleared it up for a few weeks. Then both the rough idle and the stalling on WVO got more irksome (maybe I just noticed them more). Finally, I started the van one morning last week and couldn’t get above, say, 20MPH running on diesel. I always suspected debris made it past that inline filter, so I took off the fuel lines to the low pressure pump and blew air (with a bicycle pump) to see if I could get anything to come out. Nothing did, but when I hooked it up again, there were no fuel restriction problems on diesel. Still problems when I switched over to WVO. A couple days later, it happened again. I took things apart again and put them back together, and it runs fine now on diesel, but for how long?