Greeting to all !!

A friend and I have 3 mid eighties diesel [6.9] fords that we run on wvo. We have an onboard flat plate heat exchanger but no other mods yet. The problem we seem to have is with injector pumps. They seem to be the weak spot in our program. Is it because of the wvo or because all of our trucks are over 250 k mileage?
Been a mechanic for MANY years but ave never done anything with diesel till now. Can I rebuild these pumps at home or should I buy a rebuilt unit?
It seems that they just stop working. Tore one apart and found no undo wear, no clogging and did not see any reason for the failure. [Nothing obvious]
There are 2 electric connections on the top of the pump. Should these be on when the key is on?
thymekiller

 

Howdy and welcome to the IDI secret cave

One of those connections should the be FSS (Fuel safety solenoid (or something of such)), Its the only wire you HAVE to have to make an IDI run (thus I always keep a 4 foot wire in my tool box with an aligator clip and a connect that fits that connection).

The other one is well I can't remember I think its a temperature something or another


Well 250K on an injection pump is getting up there, so it may be a combo of age and the WVO thats getting them

I would just buy a rebuilt unit because they are way to complicated and the risks are too high for (me anyway) to justify trying to save a few $$$

Heres a link to Pensacola Diesel, who I've heard several good things about, and the price ain't bad either
Pensacola Diesel Inc. - FORD 6.9L - 7.3L :: REBUILT FUEL INJECTION PUMPS

 

One is the fuel shut off (towards front of motor), the other is cold start advance.

-Enjoy
fh : )_~

 

You need to take the pump off and take it to a good injection shop. I personally don't like buying rebuilt units to ship off, I take mine to a good shop where one man builds it that knows what he is doing, as opposed to other places that build them on an assembly line. I have been running WVO for several years in mine, have had a few injection pump failures, nothing major, more than likely it is normal wear and tear. Never tell the Injection shop you are running WVO, I always pump diesel through mine before taking it to the shop. Most pump shops will void your warranty or even refuse to build pumps that have WVO, b/c they don't believe in it or have never heard of it.

 

Thanks guys. I am new to all this and was worried that We ruined the pumps from the oil. I think I will get a rebuilt unit.

thymekiller

 

Any idea how hot the WVO is going into the IP?

I saw some numbers in the alternative fuel section about what the WVO temp needs to be, but I can't remember the number.

Also are you purging the WVO before shut down?

 

Yes. I have a tempature gun that shows fuel at the filter to be the same as coolant temp [very close] because of the heat exchanger. Run time at startup and shutdown is at least 15 minutes. Generally, you can trust the temp guage. If it shows warmed up, the heat exchanger is doing its job. It is mounted in the engine bay.
BTW, if anybody wants a good cheap flat plate heat exchanger for about 20 dollars plus shipping, I will post a link. Bigger ones dont do any better, we tryied.
Something else I should mention. We run both diesel and wvo through the exchanger. I have heard alittle about thermal shock , but I do not understand. There were no broken parts inside. Fuel went in and did not come out. [Clogged maybe?]
Could a somewhat high ph level in the wvo cause this failure? On the one I torn down, I saw no evidense of gasket failure.
My biggest concern is the immeadiate destruction of a new pump.

Can anyone recommend a good maneul on these pumps? I'm not opposed to building a test stand. We have 3 of these trucks and saving money takes on a new light if they all need a new pump every 6 months. Also, cant say I dislike the challange. Depends on whether there is machine work involved. A full understanding of the unit would help us jack one up for the mud pit.

thymekiller

 

thymekiller;
thanks for the post, i also have three idi's, and my 2 cents is the weak link to these machines is that " pump" or the "don't pump"
i have burned thousands of gallons of wvo ,the idi loves it, the pump,well that's a differant story, gone threw 4 ,gotten to the point ,i can take one off and put the next one in ,around 40 min, they are a pain in the @ss ,but if i read rite on this fourm , they seam to be a problem with trucks that just burn #2 dino diesel,
i belive it is a ford problem
not a fuel problem
do they make a pump other than sandyne db2

 

please post link for heat exchanger,
what valves are you useing for switching fuel?

 

In all my travels I have never found any books on the Stanadyne IP outside the fuel injection services.

Most of my knowledge was either from the service guy at the local injection service or trial and error experimentation.

Thermal shock from cold fuel or water hitting a hot injection pump is from the steel internal parts housed in an aluminum case and the different expansion rates of the metals.

The issue is not a Ford or International issue, but a Stanadyne issue.

And there are plenty of other pumps, but getting one to fit and custom injection lines is not going to be cheap.

High ph against aluminum is not a good thing.
With all the tiny passages in the IP my bet is a clog did your IP in.

One point about the switch and purge before shut down.
When you switch tanks to purge the system, the WVO from the valve to the filter, through the IP and return system back to the valve gets diverted into the fuel tank.

Given enough times switching tanks, that could get enough WVO in the main fuel tank to cause problems in the IP on cold starts.


I did a good bit of reading on the WVO conversions a while back.
I see to many problems for them to be of any interest to me at all.
If I were going to run alternative fuel, I would be taking the WVO through the bio conversion before it went in my truck/engine.

Just looking at the viscosity of cold VO or WVO looks like a problem waiting to happen to me.

 

Dave,

Write a book!

-Enjoy
fh : )_~

 

dave;
the return of veg to the diesel tank can be a cold weather problem.
and in the beginning of my trial &error period it was!
only when the diesel tank got to low, when kept passed half, full no problems
having said that,
there were still, glow plugs,glow plug controler, return line, return line caps,`lift pump,
and of course the injector pump,
did i mention i have three of these trucks!!!!!!!
when they work they are great
but when you have to fix or repair daily it's frustrating

 

I had to have my Stanadyne rotary IP rebuilt after trying to run on WVO. took it to a very knowledgeable shop (knowledge of IPs, not wvo LOL) and one thing they told me that is of interest to you, is that there is a maximum temp for diesel running through the IP. The heat exchanger is fine for wvo, I hear that can be hotter due to the lubricity of it, but f you run diesel through the heater as well be very careful it's not too hot as the IP will seize. I don't recall the temp, but the shop had it in a book and read it off to me at the time. It was well lower than 140 degrees that is the minimum of my added temp gauge.

Stanadyne rotary pump in an '89 7.3 L IDI.

 

Thanks for all the replyies.
Heres that link;
Burden Sales Surplus Center Item Detail
There is less than 12 inches between the exchanger and the big filter. What ever the temp of coolant, thats the temp of the fuel going into the ip.
Interesting note on diesel fuel temp. Hadnt thought of that. There may be something to that. I will research / reroute one truck and find out. Perhaps the ip dosent like that high of a temp. It might use the colder fuel to cool itself. I could be cooking it. Interesting.
Cross contamination is a real issue. I dont use wvo on short trips. Sometimes we run on diesel just to run down the tank. Keeping it refreshed is important. Moving the tank switch closer to the engine would help because it shortens the line between the return and the switch. Possibly use seperate filters.
We are still using the stock fuel switch. No problems yet.
Thanks for the insight guys. I had run out of ideas but now have a fresh outlook. Moving the switch forward and putting the heater on the tank side might do the trick. The farther away the heater is the less temp at the motor. By adjusting the distance, and adding a second exchanger, I could adjust each side for reasonable temp. Wvo dosent need to be 180 degrees to run through the ip. 100 would work, I think. [ Last summer it worked without any heat at all. ] The diesel fuel could be 80 and maybe not induce thermal shock. Moving the exchanger back also would cool the exchanger down a bit.
Very interesting thoughts, guys. Thanks.
No chance of me writing a book, but I could compile a list of links.

thymekiller

 

Actually instead of moving the stock valve, what I think needs to be set up is a second valve for the return lines.

When you get ready to shut down, flip the supply side back to diesel and leave the return valve to the WVO tank while you drive the next five miles.
Then switch the return line to the dino tank.

That would keep all of the WVO out of the dino tank and give the filter a bit of a flushing with diesel before you shut down.


Heater coolant temp should be around 195 degrees, that is to hot for diesel.
The return lines are to provide cooling and extra lubrication for the injectors and IP.

With 195 degree fuel, my guess is the fuel shut off solenoid overheated and burnt out.