Pressure at IP on veggie is 5 at idle and less at 1800rpm

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Pressure at IP on veggie is 5 at idle and less at 1800rpm

Postby paulchace » Fri May 02, 2008 7:26 pm

Why, when I switch to veggie, does my gauge read 0 psi at 1800 rpm??
When I'm runnin diesel idle is 25 and at 1800 it is 20- 22 psi. Is one of my GC valves shut instead of open, is my vo supply line clogged.........the filter is brand spankin new....... hey I'll try another one.......maybe I'll blow out the pex line back to the tank. I took off the cap to the GC tank so as not to cause a vacuum there. Man this stuff sure can be frustratin'. Thanks for your help anyone. Paul
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Postby 240Volvo » Fri May 02, 2008 9:06 pm

A little more information would help get a response that would be meaningful. 0 at 1800 on VO implies that the engine is running without fuel. Is it running on VO? Are there other symptoms? Loss of power at particular times, that sort of thing?
1984 Volvo 240 diesel with a single tank Elsbett conversion: electric fuel filter heater, FPHE, glow plugs, and injectors. Also injector line heaters and block heater, running 20%kero/80%WVO winter blend.
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Postby mikeshauling » Fri May 02, 2008 9:31 pm

hey Paul, im having the same trouble with my guage readings on vo. On d2 my pressure is @ 7 psi (this is normal for my stock lift pump).When i switch to vo my guage shows @ 1-2 psi if im under lil or no throttle,when i get on the pedal the psi is at 0. Now i do have a seperate pump (walbro) it is supposed to put out @9-11 psi on vo. My truck runs fine even tho my guage reads 0. I dont have a clue, so if you or anyone figures this out then post it up, please. I took the lil screen in the pump out and cleaned it also. New filters on it also.
09 6.7 CTD
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Re: Pressure at IP on veggie is 5 at idle and less at 1800rp

Postby SunWizard » Fri May 02, 2008 11:02 pm

paulchace wrote:Why, when I switch to veggie, does my gauge read 0 psi at 1800 rpm??
When I'm runnin diesel idle is 25 and at 1800 it is 20- 22 psi. Is one of my GC valves shut instead of open, is my vo supply line clogged.........the filter is brand spankin new....... hey I'll try another one.......maybe I'll blow out the pex line back to the tank. I took off the cap to the GC tank so as not to cause a vacuum there. Man this stuff sure can be frustratin'. Thanks for your help anyone. Paul

Whats the vehicle? More details of conversion? Could be not enough heat to the VO and its having a hard time getting through the filter. Temp of VO entering filter? Or an air leak. Or a weak lift pump.

Mike, same Q & A except we know your vehicle.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
Low fossil net zero house- 100% solar power and heat.
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Postby mikeshauling » Sat May 03, 2008 7:20 am

well i have a 2 tank with HiH from the tank to engine, heated pickup teed off my 3/4 HiH Down to 1/2 to my fuel pickup. My HiH ends next to my intake horn then my coolant lines go @ 2 feet to my 26 plate/ HE. My 3/8 alum. fuel line comes from HiH then to my walbro (fr series ?). Then through my electric heated f/f (5 micron) it leaves then goes to my FPHE, which is where i have my temp guage hooked at. after that it goes to my 6 port pollack which is just before my ip.
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Postby SunWizard » Sat May 03, 2008 9:35 am

I suspect that you have a weak pump, since with HiH you should have enough heat at the filter. Still good to check the temp entering filter. There is always some pressure loss in the filter and lines, and its more on VO. So you need a pump set for and capable of more than the pressure you want at the IP to compensate for the loss.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
Low fossil net zero house- 100% solar power and heat.
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Guessing

Postby sanderlings » Sat May 03, 2008 10:30 am

When you guys say your gauge is reading zero I am guessing your gauge does not show vacuum and it is pinned at zero. It would seem that running at exactly zero pressure would require a pretty good balancing act between the lift and the injection. I have experienced a running engine with a vacuum in the supply line when I forgot to turn on the lift pump and the injection pump was supplying itself by pulling from the tank through the lift pump. I was surprised that the injection pump could do that, but it was running "fine" at 50 MPH when I noticed the vacuum and switched on the lift pump. I put fine in quotes because when I turned the lift pump on the engine sounded much happier. So I would second Sunwizard and guess it is the lift pump. You did say Pollack valve after the heat (Which made me cringe), so you may want to check that valve too.
todd
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97 Dodge

Postby paulchace » Sat May 03, 2008 10:33 am

The Greasecar tank has a hose in hose design to GC filter housing, Baldwin 781 then on to GC valves out to lift pump, (no prescreen). to Vegtherm Mega to IP. It is a 97 Dodge w/12 valve. Any other thoughts?? Thanks, paul
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Postby SunWizard » Sat May 03, 2008 10:51 am

The filter under vacuum makes me think air leaks. Check heat of the VO entering filter. Using the stock lift pump for both fuels?
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
Low fossil net zero house- 100% solar power and heat.
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97 Dodge not so fine

Postby paulchace » Sat May 03, 2008 1:32 pm

I road tested the truck and at 35 mph I had 0 psi and less, a vacuum condition. When I pulled in the driveway and stopped I noticed an air bubble in the vo supply line just before the vo filter. Other than that all looked well. I then had 5 psi at idle on vo, switched to diesel and got back to 25 after several seconds of intermittant air........any ideas? Paul
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Yes, stock lift pump for both sides

Postby paulchace » Sat May 03, 2008 2:25 pm

The lift pump is for both sides, Mark Penta told me to look for an air leak on the return side........makes sense......
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Postby mikeshauling » Sat May 03, 2008 7:31 pm

Hey Sanderlings why do you cringe at the pollack AFTER the heat, I didnt think that was a problem. Also yes my guage is pinned at 0 psi. and no i dont think it is JUST at 0 but maybe under vac. My little walbro (FR)series is supposed to be rated at 9-11 psi on vo. I dont think its bad but maybe i just need a bigger pump. I know its working because i can hear it pumping ( it rattles or hammers).
09 6.7 CTD
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That was difficult

Postby paulchace » Sat May 03, 2008 7:43 pm

I dug a little deeper this afternoon, I removed the hose from the inj pump return and the T it goes to. I replaced the hose w/ something more substantial, the inj hose for $ 3.75/ft. (30R9), that stuff hold up well. The original hose looked like a problem waiting to happen. The t was ok, although the sealing washers looked tired. Like me........I'll put it back together tomorrow. I'm hoping a lift pump is not in my future, but 5 psi on vo aint good and 0 psi at 35 mph is worse......more later, Paul
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Postby sanderlings » Sun May 04, 2008 6:34 am

Mike, if you do a search you will find a lot of back and forth posts about the pollack valve not being able to take the heat of WVO. Mine failed after about five months of light use, but some have lasted years. I don't take a stand on the valves, but I won't ever use them again either. As for the your flow, you could just do a quick check at different oil temperatures on your walbro by routing it into a bucket and see if it meets the gallons per minute you need.

Paul, I guess you are looping the return which puts all the return components into the delivery system (Which I don't think they were designed for). You could check it by just routing the return back to the tank or a test bucket and see if the problem clears up. It doesn't seem to me that you could be drawing enough air to effect your delivery pressure and still run well. If you have / buy / borrow a little electric pump you could install it in different points along your WVO system and check the flow as you go. If it is good all the way up to the stock lift pump then it would seem that the stock lift pump is not handling the WVO very well. If that ends up being the case Chase (Sorry I couldn't resist) then you could work around it with a separate WVO lift pump.
todd
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No offense taken

Postby paulchace » Sun May 04, 2008 7:52 am

I was laughing at the pun, anyway thanks for your advice. I'm putting the return back together this am. I'll test it after and let you know what I see happenin........Paul
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