• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

fuel pressure gauge sender confusion

Hi saw your thread in the transmission section first and I posted a reply there (http://www.thetruckstop.us/forum/sh...d-no-overdrive-1991-3500-4l80e&highlight=code). Leroy was correct that I changed the front speed sensor. I was hoping that fixed mine as it worked great for about 4 days, but then the problem came back. I have not had a chance to change the rear speed sensor yet, but hope to be able to do that in the next day or two.
 
Yee Haw, did i fail 2 mention I am THE words greatest one legged cowboy!!!!!! LOL I fixed it!!!!! Lets just hope it stays fixed!!!! Read on another forum that 2 set the TPS u have 2 unplug the fast idle solenoid before taking and setting the volt readings. Well yall remember this all started when I messed with the cruise control cable and it affects the fast idle solenoid 2! Then I got it to shift correctly again and when I used the cruise control it quit working so I figured they are working together somehow. Looked up setting the fast idle solenoid and found out about the little wire inside it under the rubber boot, took boot off and wiggled little very fine fragil looking wire and put back 2gether and the fast idle solenoid went back 2 working so I unplugged the thing again and used meter 2 set the TPS and it was 2 low a voltage so moved it up to more than .5 volts, its a needle type and not very easy to read such a low voltage but its somewhere between .5 and .75 and test drove it and tyed stopping shut off and everything and my beautiful 4l80e tranny is back! Not brave enough to try cruise control yet! LOL Also now that the fast idle solenoid is working it idles about 1200rpm n then when warm it falls back to 800-900, I can live with this, one day when I am ready to tavkle it I will set it lower but for now its working and I aint gonna mess with it! Thanks all of u, I think it was actually several problems and we solved one but another had to be found etc. Now back to installing the fuel pressure gauge and converting to wvo! More adventures to follow I am sure.
 
They gotta b related cause u have to unplug the fast idle solenoid to set the TPS, anyway u r right lets hope it holds up! So back to burning veggie oil, did u blend with a DB2 pump? Reading on the net it sounds like a lot of folks mess the ip up but they dont ever mention monitoring fuel pressure to the IP, do u think their problem was low pressure from the lift pump caused by clogged filter or thick oil or bad lift pump? Thats why I want 2 install a pressure gauge b4 starting any mods and gradually add new stock filter and check pressure and then add extra spin on filter and check pressure and then add blended wvo, that way if I drop down pressure wise I can adjust or repair or replace to maintain that magical 4 psi. I have seen posts that say the factory set up wont maintain 4psi at heavy throttle, what is your experience since u have a gauage?
 
DB2 yes. I would blend 10 or 15 gallons to 15-17 gallons of diesel. You might have problems later with your FSU as the WVO tends to layer over it and insulate the wiper. I do happen to sell a Metrum Rod FSU that would cure that problem (search my threads for it)
With stock LP at WOT it drops to 0-1psi With my new Walbro it mantains 12 psi at cruise and 5 psi at WOT. I would suggest removing tank sock and installing a 30 micron spin on filter w/ a better LP.

As far as WVO you better off going to a 2 tank heated system.
 
wow thats a lot of initials. Whats a FSU and whats is its wiper? I do not know how 2 search ur threads. I have a electric LP that someone added and they took the mechanical one off, I hope mine will have good pressure readings and if not I will get a Walbro. I thought I would add a 2 or 6 micron spin on and that way I would not have to change that strange looking square filter that looks awful hard to get to and hard to bleed. On my Mercedes I just fill the spin on with diesel and carefully spin it on and dont have to bleed or pump it up. I am in southern North Carolina and it seldom freezes here so I hope to get away with a single tank blend. I use wvo, reg gas and k-1 kerosene with a cetane and cleaning agent called Power service from walmart. Ten thousand miles on the Mercedes and no problem. Whar is a Metrum rod Fsu?
 
I think I've got a guess on how the TPS and fast idle are connected. you have to have the IGN on to check the TPS. as soon as you do that the fast Ilde gets power(assuming the engine is cold). then as soon as you move the throttle to check the TPS the fast idle kicks in and doesn't return the throttle back to idle.

does that make any sense whatsoever???
 
Ho ho Just A Number has a genious IQ! That would certainly cause a way bad reading, I never thought of that! So whats a fuel sending unit and whats a WIF? Remember folks I am a heck of a cowboy but just doing baby steps with this diesel thing. Allright I dont think I want to eliminate the square filter because its a fuel reservoir that lives right n all that heat from the back of the engine and that alone should heat the wvo blend a little. Also what are yall talking about a heater in the filter? Thats very interesting and could also be a tiny help in heating the wvo blend. My 1975 Mercedes runs on a 85 % wvo blend and has the muffler factory mounted up n the rear drivers side fender nice and snug to the fuel tank and the exhaust pipe runs along the fuel line. Them germans knew how to run a diesel n cold weather, I drove it on a 200 mile trip during xmas n the rare snowstorm we had with wind chill in the teens on interstate 95 and she never slowed down, just gotta let her get up to temp b4 driving. With the DB2 it will apparently shear the IP shaft when it gets a big gulp of hot fuel when the IP is cold or conversely a hot IP gets a gulp of cold fuel it shears the shaft so with the mild temps here n NC I actually think by monitoring fuel pressure and changing filters accordingly I can fairly easily run it on a blend and get a reasonable life from the IP. I intend to add a 2 or 6 micron spin on b4 the factory square filter. My question 4 yall is if the 2 micron will b 2 hard 4 the electric lift pump 2 push thru or if even the 6 micron will b to hard and if I should go with a 10 micron. I want to go with @ least the 6 micron 2 save the square filter as much as possible. I have read a lot on bio fuel forums and those guys r too n2 the chemical nature of vegetable oil and r playing chemist and r not mechanics like yall! They talk on and on about blends of wvo and never once mention a way to monitor ur fuel filter clogging other than it quits or starves and loses power and they wonder why the IP craps out! Thanks and please keep educating me please cause I am gonna run her 4 free on nveggie oil!
 
OK the FSU(fuel sending unit) is the mess in the fuel tank that gives you reading for your gauge. a WIf is the water in fuel sensor. water and diesel don't mix! as for the fuel heater there is one in the top/back plate that the filter mounts to. you are going to want atleast 2 filters. one pre LP and one post LP. the pre one collects the big stuff that can hurt the pump itself. the post one you can use a couple of different setups, just make sure you have a water separator in there somewhere. the square filter have it built in. the element has been treated to filter out the water but let the fuel through.

this will help you with all the acronyms.
http://www.thetruckstop.us/forum/showthread.php?11081-Acronyms-quot-What-you-talking-about-quot
 
Hey thanks that helps alot espeacially nthe link 2 get what the initials r 4. Can I put a simple prefilter b4 the lift pump like on the Mercedes, its a little thing that is clear and u can c if its full of crap, my NAPA dealer jokingly calls it a lawn mower filter, I think its a 30 micron, its very easy to change just two screw hose clamps and only a couple dollars. The FSU thing makes sense now my Mercedes has erratic readings for half tank verses thre quarters, best to keep track of ur miles travelled and fill accordingly. Thanks this is a lot 2 digest but nothing wrong with agitating the brain cells a little. I am going to use a water separator filter @ first but not a water block, supposedly the water block will clog with the wvo but the separator wont, something to do with the reaction btween the material, wow I hope that doesnt happen with the square filter. I tried golden rod water block filters for my wvo filter station and the wvo forum people r right they block fast and there was no water n the wvo cause I tested it. Do u think the lift pump can push the fuel thru a 2 or 6 micron filter and also the square one, thats a lot of filter media! Wonder how much heat the plate puts n2 the square filter? What is powering the heater, electric or coolant flow or exhaust routing or what?
 
I would not run the lawn mower filter its not big enough and if it becomes just alittle cloged it will starve the engine of fuel.
One thing I just thought of is you could add the 6.5 FFM inplace of your 6.2 I believe all the connectors are the same. That would also allow you to use my Fuel Pressure Tap to gauge the LP pressures. You might have to fab up a bracket. I think you will have problems with your LP pumping through a 2 micron, but give it a try you can always add a Walbro later if you have a problem.
 
orrum,
I'm curious to know what your experience is with brass fittings and copper tubing with WVO. On my truck I have a dual tank system and I originally used copper tubing and brass fittings. After a year or two I started gettting a lot of plugs. It turns out the vegatable oil polymerizes when in contact with copper. I switched to stainless tubing and fittings about a year ago and have not had any issues with plugs since then.
 
Yes according to wvo veggie chemists that will happen, all my mercedes lines r some kind of metal, dont look stainless but they r 35 years old so maybe, it does have a lot of rubber hose too, u cant use metal lines either cause the wvo causes them 2 rust. No matter how good u filter and settle the oil there is going to be water that is emulsified, u just gotta get it low enough to pass a hot frying pan splatter test and hope the engine will burn it without a problem. Best to use viton hoses. U know it will polymerize ur engine oil too, best to not go over 3000 miles on a change. I have not had a problem so far but remember that a old mechanical Mercedes will pump and burn peanut butter and jelly sandwiches! LOL What gets me is how bad a rep the DB2 IP gets 4 not being able 2 handle wvo and then they all brag about how great the older Ford Powerstrokes r 2 veggie oil and they use the same DB2 IP except it rotates n the opposite direction! Duh, I seriously dont get it. I do believe a single tank blend system will work just fine but u gotta watch the weather and adjust ur blend accordingly and use electric injection line heaters . The way I look at it a two tank system takes away most of the cost advantage, with a two tank u gotta burn 10-15 miles of diesel befor switching and then u still need 2 burn a blend n the second tank cause straight wvo requires a lot of heat and that heat takes money to install and maintain! I use 2 deliver newspapers @ nite with the lites all on bright and the heater motor running full blast and the windshield wipers going full n the rain and let me tell u a alternator dont last long n they cost money! Also with a two tank system u got more filters 2 maintain. My blend costs a little less than a dollar a gallon, add the cost of running diesel n the startup tank and then figure n a value 4 filters etc and honestly the savings gets 2 be pretty slim partner. So I am either going to run a single tank blend or mess up the truck and give up and go back to diesel. Hey u wanna hear a good one I met a old guy that was a warrant officer in Germany after WW2 and he told me how 2 set my old Mercedes 2 run off the smoke from oak leaves! I researched it and they did do it n Germany for tractors and cars both, not very fast, more like a very fast idle up to a road speed and u still had to let it idle off diesel but the smoke does burn and increase rpms! Do u run a blend or straight wvo n ur second tank?
 
Cool finally someone believes me! The old man said it was really easy with my old 240d Mercedes cause the throttle for the oak leaf smoke was the butterfly in the air intake, just hook a cable to it and the more u open it the more air and smoke it sucks and the faster it goes. I think them germans found more spaceships than we did, we only had Roswell n area 51! LOL Lot of knowledge and experience on this forum. I am sure yall have worked hard to acquire ur skill sets and I am so glad u r willing to share with others. Bet some mechanic would of got rich off fixing my TPS, bad ground, and not functioning fast idle switch plus probably plenty of parts. We all fixed it and it cost me two scraped knuckles and about a dozen stabs with the wire probs n2 my finger tips, no money involve!!!!!!! Thanks again.
 
diesels are harder to run on smoke you have to run it on diesel and add smoke to reduce the amount of fuel you use. Gassers can run on it straight. it's actually more complicated than it sounds you have to have really dry wood/leaves/peat and you have to filter the "smoke" so that it doesn't gum up the engine. all you want is the actual combustible gas in the smoke.
 
I usually run straight wvo in the second tank. I used a 40 gallon tank from a suburban and moved the spare tire to the bed. All your comments about wvo I agree with. Knowing what I know now, I would not bother with the second tank, I would run a mix like you say. I dont use electric heaters though, I use homemade tube-in-hose heaters and heat the oil with engine coolant. What electric heaters do you use?
 
You must log in or register to reply here.
Back
Top