Losing prime overnight (or sooner) 1HZ (3 Viewers)

[SKULLYOTA]

Trying to diagnose a starting/idling issue with my 1HZ that popped up recently. Looking for advice on where to start....


I had removed the ACSD awhile back and bought a block off plate to go in its place. After the swap, I primed the fuel filter button until i felt resistance and the cruiser started right up, no issues. Didn't drive it much for awhile. Didn't re-time the pump, but it seemed that it ran the exact same and normally. The ACSD was completely locked up and frozen when it was removed.

A few months later, it feels that it takes a lot of cranking to get it to fire up and the initial idle is rough and I have to run it at about 2000rpm for about a minute to clear it out.

I started checking the primer on the fuel pump in the mornings and discovered it will take over a dozen pumps to get it hard again and then it starts just like she used to.

Idling in traffic during red lights the idle will start to intermittently cough or stutter but come right back.

So, I deduced that it is losing pressure somehow after I park it for the day/night. The occasional idle stutter in traffic makes me think it loses pressure pretty quick.

First thing I tried was removing 3 glow plugs and trying to bleed trapped air. Didn't appear to have an effect.

I have a set of new replacement injectors in my parts stash, and have ordered a new fuel filter top/pump.

My plan was to replace the filter top/primer pump in case it is bad, then the injectors in case they are leaking down? Is there anything common or obvious that I should try before sending the IP out to be rebuilt?? I was surfing some Ford IDI forum posts and saw that the return line check valve is the problem with them. Does the 1HZ IP have this issue?


appreciate any help or pointers.


EDIT: found this thread

1HD-T - Possible air leak from fuel primer ?

The cruiser hasn't been starting up as quick as she used to, being a Di she used to fire as soon as i flicked the key, now it cranks for a couple seconds. I don't know whether it is an air leak or a dying starter, batteries are only a few months old and it had a rebuild 10k/km's ago, drives mint...

forum.ih8mud.com

So maybe the rubber lines between the IP/hardlines/fuel filter and even the water/sediment trap in the bottom of the filter?

 

[AussieHJCruza]

Primer/Fuel filter head would be my first port of call, and after that, replace fuel soft lines and clamps.

Very unlikely that the injectors are causing this, they only get fuel at their allotted firing time, unlike a petrol or commonrail diesel engine.

Don't go spending thousands on an injector pump rebuild to fix an air leak, also very unlikely to be caused by the IP, replace the cheap and easy things first.

 

[roscoFJ73]

My plan was to replace the filter top/primer pump in case it is bad

I think that's what it is. Most likely the valves inside are leaking and the fuel is running back to the tank.
I would connect a short piece of hose to the filter inlet and place the other end into a container. The container should be empty in the morning. If its not you will know its running back to the tank.

 

[roscoFJ73]

also very unlikely to be caused by the IP

I agree. If the pump was leaking you would have fuel leaking. The fuel lines don't leak because they are in vacuum, but the pump leaks like sieve when it leaks.

 

[SKULLYOTA]

Thank you guys for the feedback so far. The fuel filter top has not arrived from PS yet, and I also ordered some rubber lines and the new water separator for the filter bottom.

 

[SKULLYOTA]

I installed the new fuel filter top, new filter bottom sensor thing, three new hoses and a new prefilter housing. I pumped the primer till it got hard and it fired right up after smoking a little. ran it for awhile in the driveway, i will start it in a couple days to see if it held pressure. there was one hose I did not have enough on hand to replace

 

[tmarx]

Had the same due to cracks in the fuel hoses which was caused by over-stretched stock size fuel hoses going to the larger size Racor filter fittings ...

 

[hellmansam]

I recently had trouble with my 80 losing prime while driving. Replaced the filter cap, thought it was all good but the problem came back pretty quickly. Turned out to be related to the Sub tank being empty, the solenoid valve must not seal properly.

I'd had it for a year and had used but never emptied the Sub tank.

Narrowed it down by using clear PVC tubing in place of the fuel line. First from the filter cap back to the last section of hard piping (@ the firewall) then from the filter cap to the main tank. Bingo, no air bubbles.

Drove it back home and while underneath looking at the sub tank, realised it was empty and that's where the 'air leak' could be. Put 20 litres in and connected the fuel lines back as normal except for the last section to the filter cap, so I could watch for bubbles.

Selected the Sub tank and fired her up. Watched the bubbles gradually disappear and went for a drive, gave it a good workout. Symptoms gone.

Haven't fixed the cause as yet but I know to avoid running the Sub tank out for now.

 

[SKULLYOTA]

Well my problem is still with me, after replacing the fuel filter, primer pump top, adding a prefilter and changing three of the four rubber lines that connect them all. Have not been able to change the longest of the rubber lines yet. the issue is a little better at home and when its warmed up, but this morning waaay up in the mountains it was rough starting it at 50* F and made a sh*t ton of smoke of various colors.

Going to try the last rubber line from the fuel filter to the tank, then remove all the glow-plugs and bleed it. If it contines i'm going to suspect pump timing or the IP itself

 

[Squash]

I have ran a few diesels out of fuel but stop the first time they stall.
If you add fuel to the tank I've never had to prime. On the other hand I've had a diesel were water was added to the fuel and yes we drained the tank and cracked injectors.
From my experience if you get a diesel to fire up she will purge air from the system unless the system is sucking air.
Do yourself a favour and try the clear hose trick between your OEM filter and the IP. If you see lots of air bubbles the the issue is towards the tank/tanks.
Otherwise use a short section of clear hose and feed the pump directly with a fuel can held above the IP thereby eliminating any other issues upstream.
From this point on it's a simple process of elimination. Be very certain of pre-filter joints as I've seen a few issues of leaking fittings.

 

[roscoFJ73]

If it contines i'm going to suspect pump timing or the IP itself

Pump timing doesn't go bad overnight, it takes years and years and it never gets that bad it wont run right.. If the pump was bad, it wouldn't get better when warm.
Have you tried a piece of clear hose between the filter and IP? Or set up a different fuel supply.

I was surfing some Ford IDI forum posts and saw that the return line check valve is the problem with them. Does the 1HZ IP have this issue?

Ive seen it on other diesels but it was from a build of wax residue in the fuel causing the bypass valve to stay open.

ALWAYS ask for a bench test on your IP. Never talk about rebuilds to them until they can definitely say it needs one. If they are not making weird noises and getting full pressure, they are generally good.

What is it idling at when warmed up?

 

[SKULLYOTA]

Pump timing doesn't go bad overnight, it takes years and years and it never gets that bad it wont run right.. If the pump was bad, it wouldn't get better when warm.
Have you tried a piece of clear hose between the filter and IP? Or set up a different fuel supply.



Ive seen it on other diesels but it was from a build of wax residue in the fuel causing the bypass valve to stay open.

ALWAYS ask for a bench test on your IP. Never talk about rebuilds to them until they can definitely say it needs one. If they are not making weird noises and getting full pressure, they are generally good.

What is it idling at when warmed up?

I did recently remove the ACSD and install a block off plate. The ACSD lines were completely plugged and it appeared the ACSD was non-functional. It idles pretty well around 900-1000rpm. I didn’t think to retime the IP afterward

I just this morning removed all 6 glow plugs, laid some cardboard over the holes and spun the motor for awhile. 6 perfect round spots of diesel on the cardboard. Put it back together and it had the same gray smoke and stumbling idle until I cleared it out with the accelerator pedal.

I guess I’ll just keep changing rubber lines? There’s a few I haven’t gotten yet

 

[SKULLYOTA]

It also seems to crank for awhile before starting and just doesn’t want to idle unless I run it out with the pedal for awhile. Also doesn’t seem to matter if it’s been sitting for 5minutes or five days. I can still pump the primer about ten times before starting either way.

 

[BarnFab]

Going to try the last rubber line from the fuel filter to the tank, then remove all the glow-plugs and bleed it. If it contines i'm going to suspect pump timing or the IP itself

Just to be clear removeing glow plugs does nothing to bleed injectors or lines directly it just allows the engine to turn over easier / faster truning the OP faster and thus pumping more fuel.

If you want to "bleed" your injectors you need to crack the 17mm nut going to the injector and check to see a nice mist, that being said if you have checked the misting frm your Glow Plugs there is probably no need to bleed them.

What did you see with the clear line connected ? Air Bubbles / No Bubbles ?

 

[roscoFJ73]

How many klms has the engine/pump done?

 

[roscoFJ73]

Just to be clear removeing glow plugs does nothing to bleed injectors or lines directly

Its always worked for me providing the fuel lines and fittings are not leaking air. It also gives you the opportunity to see if all injectors are spraying fuel.

 

[roscoFJ73]

I can still pump the primer about ten times before starting either way.

Does it make a difference? The primer is not meant to be hard all the time.

 

[DivByZero]

You sure it's not just a problem with your glow plugs and starting in the cold? I had a leak like this from my primer pump, and when the fuel drained back to the tank I had to pump quite a lot to get fuel back through, like 50 times or something. How many times are you having to press the pump before it gets hard to press any more? Does the car fire up in a few seconds either way, it just runs rough at the start, or does it not start at all unless you prime? If you had an air leak, I'd expect you could crank for 20 seconds or so and not fire unless you primed. Is that what you see happening?

 

[roscoFJ73]

like 50 times or something

That was a clue in itself. The FSM says the primer should bring fuel from the tank to the filter in 30 pumps.

 

[SKULLYOTA]

Glowplugs are only a couple years old, genuine toyota replacements

You sure it's not just a problem with your glow plugs and starting in the cold? I had a leak like this from my primer pump, and when the fuel drained back to the tank I had to pump quite a lot to get fuel back through, like 50 times or something. How many times are you having to press the pump before it gets hard to press any more? Does the car fire up in a few seconds either way, it just runs rough at the start, or does it not start at all unless you prime? If you had an air leak, I'd expect you could crank for 20 seconds or so and not fire unless you primed. Is that what you see happening?

The situation with starting/idling is definitely better if I prime the system first.


Engine/IP have about 300,000Km's so the IP is probably getting old anyway. I have a used one coming in the mail that I was planning to send back out for a rebuild to have it on hand.

I changed the long rubber line (about 30" long) between the hardline on the frame and the prefilter. It might be too soon to say, but changing that one made a noticeable difference in how it idled. It mighta been sucking air along with fuel out of the tank. I will drive it tomorrow and report back.

Its always worked for me providing the fuel lines and fittings are not leaking air. It also gives you the opportunity to see if all injectors are spraying fuel.

I figured it was the way to do it, saw it in some previous postings of yours. Makes sense to do it that way to me

Does it make a difference? The primer is not meant to be hard all the time.

You're right, but I feel like I can almost get 20 in sometimes.