Fuel Pump Diagnosis & Fix Part 1/2 - Diesel IDI Ford - Electric vs. Mechanical

[CORRIGEEN71]

what about timing it seems that this fuel pump is just pumping all the time like a tap and the injectors just open at will , so the original fuel pump is running dry but doing the timing for the injectors to open and close at the correct time to allow fuel from the inline pump have i got this right? would ya not burn out the new fuel pump and the original diesel pump running dry iam confused or confusing the issue???

[maxhauler]

@CORRIGEEN71 there are effectively 3 pumps in this system (2 built into the 'Injection Pump') and only the last one handles timed, high-pressure impulses. I replaced the first pump, the 'lift' pump with the green electric, whereas the original is mechanical. The next 2 pumps are inside the Injection Pump unit. The first is called a 'supply' or 'feed' pump which just helps pull fuel from the filter. The supply/feed pump is designed to pump an excess. (continued)

[CORRIGEEN71]

@maxhauler Thanks for the info have a citreon xantia diesel blowing white smoke running rough when at thickover seems ok otherwise got 120 mph out of it yesterday with 160k on the clock

[maxhauler]

@CORRIGEEN71 white smoke from a diesel generally means not enough fuel, which can occur to individual cylinders if it is a stuck or plugged injector, or it can occur to all cylinders if there is air in the system before the injection pump. this will change with RPM, temperature, when the air is pushed out of the system, when a stuck injector gets unstuck sometimes. look for when it changes. Make sure what you are seeing is not white steam or (nearly-white) blue smoke. Let me know.

[maxhauler]

@CORRIGEEN71 (continued) .. White steam disappears quicker (looks like steam not smoke) and occurs when a blown head-gasket lets coolant/water into the cylinder. Blue smoke (almost white/grey) is from burning oil which usually means worn rings. Of course you are almost certainly seeing white smoke and it probably means you consider the fuel system. My pleasure to give info. 120 mph is fast for a little diesel! Wish the USA had more diesels like Europe has.

[maxhauler]

@CORRIGEEN71 (continuing) The Injection Pump unit has a bypass so that excess fuel goes back to the tank. But the fuel you burn and the excess fuel all flows through the internals of the Injection Pump unit thus lubricating it. (This is why lubricity-enhancing additives are important.) The fuel which is pumped at high pressure, at exactly-timed instants is taken from this excess flow of fuel. The third and final pump is therefore the timed, high-pressure injection pump.

[grumpyjamaican]

thanks max for all your help i got a new priming diesel pump in from canada put it on and it fired right up hahahahahaha i am one happy jamaican right now lol :) now i can get back to work thanks again max have a great day my friend :)

[grumpyjamaican]

hi maxhauler how are you i am having the same problem with my truck the mechanical lift pump on my (1991 ford f350 diesel with 157k miles went out on me on the 7th of november2011) i did the same thing as you replacing the fuel filter installing the same electronic fuel pump and still no start ,i also replace the glow plugs 2 new battery oil change and controller module still no start,please help me if you can thanks.

[maxhauler]

@grumpyjamaican hey man I'll be happy to help. I would disconnect the supply to the injection pump and then activate your electric pump. Make sure fuel is coming out and that will help prime the filter head. Reconnect it before too much fuel drips back out after your test. Next; crack open all of the injector lines at the injectors. Don't unscrew all that much, just crack open and maybe up to 1 full turn backing off. CONTINUED

[maxhauler]

@grumpyjamaican CONTINUED .. Now with injector lines cracked open like that we can accomplish 2 things: do a final bleed/prime of the fuel system all the way to the injectors to get all air out and also we can verify that the injection pump is working. Crank the engine for 30 seconds. Let your starter cool off for 2 minutes. Repeat this crank-cool cycle about 4 times so that we've done plenty of cranking to bleed out all air and see fuel coming out at all injectors. CONTINUED 2

[maxhauler]

@grumpyjamaican CONTINUED 3 .. So now reconnect all injectors and it might start now if all you needed was to prime the filter head and lines and injection pump with fuel, thus removing the air. If it still won't start when you know you are getting fuel, your next suspect are the glow plugs. check google or youtube or ways to test your glow plugs or ask me about that if you can't find more info. Let me know if you still can't start and we can consider other things too. Good luck!

[maxhauler]

@Compassboats I think getting a good electric pump which might even include it's own filtration is a great way to go. Remember you only want about 5-10 PSI on that pump and it's worth a good amount of research. I would install it just on the engine side of the tank-switching valve if you have dual tanks. Let me know how things are going by commenting one of these vids and I'll do my best to advise you as I can.

[Compassboats]

@maxhauler Thanks, I just bought a kit with all of the injector seals and hoses, because they all leak minorly. I figure if fuel can come out, air can come in. But it sounds like it could also be the check valve in the fuel pump like Edzgarage said. When i finally prime it up, it will run fine. after sitting however, it loses prime. This couldnt be the lift pump right?

[maxhauler]

@Compassboats yes if it eventually runs and can get up to speed then your lift pump is ok. leaks in the top of the fuel system can/will let air in as gravity pulls on the fuel which is sitting in there. i think there are check valves both on the injector pump fuel return exit and on the filter head (deleted on my truck so not sure on the filterhead valve) I think these vavles are attempts to prevent leak-driven gravity-withdrawl of fuel, which creates hard start. that kit might solve it.

[maxhauler]

@Compassboats Because the problem came on quickly I would highly suspect the lift pump down on the lower right front of the block. The injection pump also has a supply pump built into it, in addition to it's high-pressure pump, so it can pull some fuel from the filter head by itself, but if the lift pump is dying or dead, the injection pump's supply pump will not keep you running for long. Be careful never to crank for more than 45 seconds without a 2-3 minutes pause for the starter to cool.

[SuperDutyCummins]

thanks for the great video! great picture too btw, thats a smart way of doing it, thats what i love about the 12 valve cummins, all mechanical, even the lift pump

[edzgarage]

I was having a lot of trouble starting my 6.9l F250 after it sitting all night. I had to crank and crank then it would start. If I shut it off and restarted it, it would start right up. Turned out the mechanical fuel pump was loosing prime because the check valve was defective. Once I replaced the pump I could start the right up after a week of sitting.

Good video.

[maxhauler]

@edzgarage yeah that sure sounds like air was getting in the system. If you are referring to the check valve coming off the injection pump (build into the elbow for the fuel return) .. well someone totally removed that from my engine as well as removed the line sending some fuel back to the filter head. I'm researching and considering putting that stuff back but they say you don't need it and my truck runs fine.

[tom58c]

I had my fuel pump go bad back in the summer. I ended up sucking on the hose like a straw to get fuel from the tank up to past the fuel pump so i wouldnt have to crank it as much. And yes, diesel tastes very bad lol.

[maxhauler]

@tom58c ha ha tasty! I got out of that habit back when I mostly worked on gas engines. I imagine diesel doesn't taste much better than gasoline, but I don't feel a huge need to find out for sure. :)