Bleed Question CAV injection pump

[NewHolland3430]

Hey new to the forum but have been lurking for a while.

Having some fuel delivery issues with my 3430 and having trouble resolving them, hoping someone with more experience could help out

Some back story:
I ran my NH 3430 out of fuel a few months back, low fuel on a steep slope. Got it running with starter fluid and was able to get it parked. After that it had been starting and running well but after some work it would stall out. more specifically RPMS would die down then it would come back to idle then it would die down then it would come back to idle. it sat for a little while and i performed a bleed that i had it running alright. but the problem came back and now it is stalled mid project not starting at all.

So i pulled the fuel bowl, cleaned that, replaced the fuel filter, replaced both air filters, and am attempting to get a good bleed on it.

Bleeding through the filter is good and i think there is sufficient fuel flow there. When i go to bleed the injection pump it spits fuel as the key is first turned then as the key is being released. so it is not bleeding when the starter is in full tilt.

same obviously goes for the injector piping at the moment.

In the past many times ive tried to bleed this thing recently ive had different experiences with this. i.e. some times it bleeds well when starter is fully engaged and sometimes it is just bleeding at the beginning and end of key turn. But at this time it is only with the key turn or release.

I am hoping this is a symptom of something but not so well acquainted with this sort of thing yet.

I am reading in the owners manual that the "stop control" is supposed to be "out" when bleeding the injection pump but cannot for the life of me figure out what that is.Is this the solenoid? should i remove the wire to bleed?

also i had been bleeding at idle and i think i am now realizing that perhaps i should have the throttle raised to get a better bleed but i don't think this is going to solve my problem entirely.

Any help here would be appreciated I know its just one simple think i am missing here.

92 ford NH 3430 CAV injection pump 3 cyl diesel

 

[Steve@Advance]

Sounds like possibly, for a better term, an ignition switch problem.

You want power to the run solenoid with the switch on, and when in the cranking position.

If you have a test light or volt meter, check for power at the solenoid. It will drop some during cranking, but not drop to zero.

Or you can try removing the wire, connect a jumper directly from the battery to the solenoid, see if it will start.

 

[jtwat]

After checking what Steve said to do. Check flow from fuel pump while cranking. I just had the same issue with my MF.

 

[NewHolland3430]

no i don't think that is the issue unfortunatly

i found some more literature on bleeding and bled the line from the filter to the IP on the upper side with tank pressure. i did see some air escape in doing this.

secondly i think i found the "stop control" its a lever on the top right side of the pump. in actuating the mechanism while cranking i was able to get alot more fuel to bleed through the IP. I bled that for a while then released the lever and it was bleeding pretty well during cranking.

at this point it was able to sustain a terrible idle maybe only one cylinder firing. i loosed all injector lines and cranked for a little while then put them back.

then it was sustaining that rough idle and i loosed one fuel line at a time and was having i felt pretty good success bleeding the lines but i never improved the idle in doing so. had the throttle all the way down during this bleed.

letting it sit over night then i guess ill try again in the morning. only thing i can think to do is start over with the bleed.

 

[NewHolland3430]

what did you have a bad fuel pump? pretty sure my NH does not have a fuel pump it is gravity to the IP.

 

[derwen1959]

there has been no mention of lift pump... perhaps there is not one??

 

[Moonlite37]

Remove return line from the pump and see if the check valve in the return line fitting is working. I had a couple that had the return fitting clogged fro particles from the governor ring clogging the return. I broke out the glass-like ball in the return fitting and it ran well until I had the pump repaired with a new governor ring. I hope somebody who has more experience shall reply.

 

[showcrop]

I was having a similar problem with my 1996 Ford 8240. I kept having to bleed air out. I went over all the line connections, snugging them up, and the problem went away.

 

[NewHolland3430]

no lift pump/fuel pump.

turned it over this morning and it fired up like it wanted to live but rpms receded to the pulsing idle where it kicks for a few then it chokes back to almost dying repeating for a little while now its back to dead again.

after that i tried turning it over with 2 injectors loose and fuel out put was less than full and one not really pushing any or intermittent

Now im starting the bleed again at the IP and plan to push alot of fuel before moving to the injectors to see if that helps.

 

[NewHolland3430]

(quoted from post at 05:36:19 07/29/18) Remove return line from the pump and see if the check valve in the return line fitting is working. I had a couple that had the return fitting clogged fro particles from the governor ring clogging the return. I broke out the glass-like ball in the return fitting and it ran well until I had the pump repaired with a new governor ring. I hope somebody who has more experience shall reply.

Injection pump. notice the wire holding that mechanism. i believe thats the fuel stop control and seen engaged while bleeding. bleed screw on center left body of pump.

piping from left to right is inlet from filter, three injectors, another inlet from filter, that upper one connects to the intake system so maybe for vacuum, and the one on the far right connects to what i believe is the return line that runs across all the injectors back to the tank





here are the injectors with that return line running across all of them then up and back to the fuel tank.

i read about this check valve before. I have already once removed that return line from the pump and blew it with compressed air and it was not blocked. perhaps i dont have this valve or i have not looked in the right place.

hopefully the pictures help thanks for your help so far!

 

[NewHolland3430]

went out and snugged all the intake plumbing, everything was already tight.

Now i am running fuel through the bleed port with the stop on to make sure i have a good bleed on IP. Seems to have some bubbles in it still but im not sure if this is just from passing by the screw. after 5 minutes of intermittent cranking. seems to be plenty of clean fuel bleeding while cranking but at the end of a crank it will push out some bubbles

giving it a rest and going at it again. i think i want to see no bubbles

 

[NewHolland3430]

Ok so after bleeding judiciously with the IP bleed screw. i disengaged the stop control it resumed the pulsing idle.

i read about another bleed screw on the back of the pump that is hard to get to. i read that it is not necessary to bleed this one because for whatever reason it will happen automatically. but i cracked it and cranked for a bit and firing was greatly improved.

then i took to the injectors one at a time. when i opened an injector it would run a little better but still pulsing then dying.

i went over each injector for a pretty good amount of time. still producing bubbles but i think that high pressure fuel passing through screw threads would cause this. either way gave each cylinder a fair shake bleeding.

then it was still just pulsing.

i stopped it and came back a little later and reduced the throttle and lo and behold it was holding a decent idle. raised it halfway to 540 and it was holding but once i got up near higher rpms it would crash then surge then crash then surge.

so i took the idle and parked the damn thing. thank god that was half of my trouble was having it in the field!

now i think i have deduced that there is some restriction from the fuel tank. i know there is a strainer in there but never checked it because i had flow to the pump, but now i think im still not getting full flow. so i think i will take a breath, replace that part and hopefully just have to bleed the filter and she should be good.

what do you guys think?

 

[showcrop]

(quoted from post at 11:50:40 07/29/18) Ok so after bleeding judiciously with the IP bleed screw. i disengaged the stop control it resumed the pulsing idle.

i read about another bleed screw on the back of the pump that is hard to get to. i read that it is not necessary to bleed this one because for whatever reason it will happen automatically. but i cracked it and cranked for a bit and firing was greatly improved.

then i took to the injectors one at a time. when i opened an injector it would run a little better but still pulsing then dying.

i went over each injector for a pretty good amount of time. still producing bubbles but i think that high pressure fuel passing through screw threads would cause this. either way gave each cylinder a fair shake bleeding.

then it was still just pulsing.

i stopped it and came back a little later and reduced the throttle and lo and behold it was holding a decent idle. raised it halfway to 540 and it was holding but once i got up near higher rpms it would crash then surge then crash then surge.

so i took the idle and parked the damn thing. thank god that was half of my trouble was having it in the field!

now i think i have deduced that there is some restriction from the fuel tank. i know there is a strainer in there but never checked it because i had flow to the pump, but now i think im still not getting full flow. so i think i will take a breath, replace that part and hopefully just have to bleed the filter and she should be good.

what do you guys think?

Eureka you have it!!!! Surging up and down is classic running out of fuel. Some fuel to the pump is nice, enough to run on is SOOO much better. I have had this experience a few times. Once it was at a tee like Moonlight described. it would run all day at an idle, even a high idle, but let the governor try to put some fuel in to do some work and it would stumble. I just had to clean out the mud stuck at the tee. You may need to remove the tank tap. It would be good preventive maintenance anyway. I have had good luck removing a lot of crud from fuel tanks with a siphon.

 

[NewHolland3430]

yea and especially trying to bleed with throttle all the way out i was not doing myself any favors hah. I guess thats my plan is to rebuild the bottom of the tank. that tap valve developed a slow leak in this effort so now its needed to be done for 2 reasons so that makes it easier.

I will report back after i replace that with what i find.

i am thinking now that the vacuum created by restricted flow perhaps pulled some air into my fuel supply through a loose fitting causing it to lose bleed and not start. But that wont be confirmed until i get it running right... glad i have at least an idea though that fits my symptoms.

 

[thepumpguysc]

1st thing.. when you changed the fuel filters, did you put the big oring UP IN the filter head or ON the filter?
VERY IMPORTANT>> the oring goes UP IN the filter head.. NOT ON the filter.. that's step 1.. check it to BE SURE.
Next, the shut-off lever in your picture IS in the shut off position.!! it'll NEVER run like that.. Move it to the RUN position.. push it in.. the long end of the lever points towards the engine to run..
Pull the THROTTLE wide open..Loosen ALL THE LINES AT THE INJECTORS & spin the engine.. wait until clear fuel spurts out & NO AIR.. & tighten all the lines.. crank the engine w/ the throttle wide open.. once it starts, move it to half throttle until the air is completely worked out..you'll know because the rpms will pick up.. THEN idle it..
Good luck.

 

[Dieseltech]

Photo of original CAV and NAPA/WIX filters. MAKE SURE on the second the filter top outer groove does NOT have an O ring in it, common mistake on that filter..

 

[NewHolland3430]

yea I'm pretty sure i put it up in the housing. Thats a good tip though. might have done it otherwise if the old one was not stuck up in there.

 

[NewHolland3430]

So i replaced the tank tap and screen yesterday after draining the tank. There was over 5 gal in there of a half fill from january. I guess im going to treat for water before i put it back.

So the condition of the screen was slightly mucked up but honestly it seemed to be fully functional so perhaps i am experiencing a blockage in the IP.

I plan to refill tank and see if it sustains good flow, and if so then hopefully I'm good but if not where should i look at next for fuel blockages shy of dismantling the IP? some of you sounded like you had direct experience with that on this pump

if it dies i will definitely verify the o-ring on the filter but I'm sure i put it in the housing and i think if i did not then it would be leaking fuel everywhere.

Either way thanks for everyone's input!

 

[Destroked 450]

One common problem with that particular pump is the electric fuel shut down solenoid in the bottom of the pump, they are known to go bad.
I'd replace it before venturing any farther or maybe one of the pump guys can tell you how to test the system without it.

 

[showcrop]

NewHolland3430, everyone is trying to get an answer to the question "Do you have flow to the pump?" you say that you do, but what do you consider to be flow? you need to have a steady stream not a dribble. Before doing the difficult and expensive you need to remove the line into your pump, and verify that you have a steady stream of fuel available to the pump.

 

[oldhousehugger]

I have discovered a technique which I think is dirt simple and may help you discover what the problem is. Take the fuel supply line loose from the injector pump bypassing the filters. Take a pump up garden sprayer that you've dumped all the roundup out of. Rinse and dry it. Put about a gallon of fresh clean diesel in it. Now disconnect the nozzle from the wand leaving the control valve attached to the hose. Make an adapter to thread into the injector pump where you removed the original supply line. Now pump up some pressure in the sprayer tank. Squirt some clean diesel thru the wand to clean out any debris and then connect the sprayer wand to the adapter with a piece of hose.
Use the valve on the wand to supply fuel under pressure to the injector pump. Bleed the pump. There’s no need to crank the engine until you have bled all the air out. Crack the injectors. Now crank the engine until you get fuel from the injector lines. Then, see if it will start and run.
If it won’t run at that point you can tell there is a problem with the injector pump itself. If it runs OK attached to the pressurized feed then the problem is upstream somewhere. You can work your way back towards the tank until you find the source of the problem. Nice thing about putting pressure in the lines is the leaks become obvious really fast.