1HD-FTE Losing Prime When Parked (1 Viewer)

[gnarlynick2072]

A couple of thoughts Nick - what are your symptoms apart from loss of prime? Hard starting? Rough running? I’m not guaranteeing, but could the “loss of prime” be a red herring? The primer pump never stays hard, my fte takes a few pumps (just tried it cold - took 10 after its been sitting for a week but I know it’s start straight up), I’ll try it straight at the I’ve turned it off next time but it always takes a few - even my brand new VDJ79 takes 3 pumps straight after shutting down. The fuel should always leak back through the return line - the check valve in the pump keeps the low pressure delivery side at a certain pressure (probably around 2-6psi at a guess), and the primer pump must be able to produce more than this so it will always be able to cycle fuel through it and it must escape via the check valve after running or pumping. Try another Toyota diesel and see if it does the same - at a guess it will behave the same.

If loss of prime through the IP is really the issue - a simple replacement of the check valve is all that would be needed. I’ve done it a few times on big truck pumps and it’s a pretty routine job. Admittedly it’s not something I’ve across with Toyotas or rotary pumps.

EDIT - just tried my HZJ75. 10 pumps cold (it always starts instantly), straight after shutting it down 8 pumps till it’s hard

This is EXACTLY the response I was looking for!

I'll give it another look through next week with some updates.

 

[69FJ40HILIX]

I hve farm equipment that is old and tired. My tractor, my dump truck (international) and my 212 CAT grader all have hte issue of bleeding back. I put one of the above pumps inline and wired it ti the ignition switch on position. When I got to them after months of sitting I turn the key on for about 15-20 sec and they all start immediately. The pumps are 2.5 PSI and dont interfere with the flow from the manual pump. On my dump truck I wired it to a toggle switch on the dashboard turn it on like the others then start it, I then turn the switch off as the manual motor pump does well after it starts. If pumping by hand every time is a problem I'd recommend this approach. Just my 2 cents. $10.99 on Amazon and free shipping.

 

[Loober]

Hi all and @gnarlynick2072 , I am having a similar issue on my 1HDFT I've been chasing for years. My symptoms are the following:

At startup when the truck is cold I get a large amount of white smoke, upon driving it a short distance under load the smoke seems to "burn off" and clears up. Under idle it continues to smoke for a while until the truck warms up. This is exaggerated in colder ambient temps and especially in elevation, truck has to get completely to temp before it stops visibly smoking. The truck runs great otherwise, its more of an annoyance and embarrassment at this point. I have done all the above mentioned tests and remedies. Compression is good, does not burn oil, rebuilt pump/injectors, replaced/checked all lines, replaced primer, performed the clear hose test...no air leaks found.

Recently been playing around with the primer...it gets hard after 3-4 pumps, a few seconds later softens up. With the engine off, Upon removing the return line, diesel pours out as I prime. Now I can understand this function when running, but could this be the culprit of air making its way into the system when the truck has been sitting a while, exaggerated in the cold due to air being more thin?

Where is the check valve mentioned above located?

Another theory is a valve that is borderline sealing, once cold metal contracts enough to allow air to seep in screwing up the combustion process, creating a white smoke condition. Once metal is warm it expands and seals appropriately. Possibility?

 

[Squash]

The important question...does the engine fire up and run normal without having to prime?
If yes, then keep driving.
Noticed that my HD-FT primer is never as hard as my 1HZ, nor the BJ74, but the FT always starts.
Huge guess would be the spill valve as everything else you've done seems stellar.


White smoke is a condition of poor glow plug/screen function. Depending on temperature and the coolant sensor.
You can try glowing a couple of times or even unplugging the coolant sensor during those marginal days when it really only cool outside, check the condition of smoke and then decide if you need to dig in a little further Into the glow system.

 

[Loober]

My HDFT was transplanted into my HZJ77, the glow screen has never been hooked up. I live in socal, the weather never really gets "cold" here. Ive been told the glow screen really is not needed and more of an emissions function. I've seen videos of FTs starting in bitter cold without the screen and no smoke. It will be a big effort to put in the electrical infrastructure for it to work, I haven't been motivated to go through all the trouble without having the confidence that will fix the issue.

 

[Squash]

My HDFT was transplanted into my HZJ77, the glow screen has never been hooked up. I live in socal, the weather never really gets "cold" here. Ive been told the glow screen really is not needed and more of an emissions function. I've seen videos of FTs starting in bitter cold without the screen and no smoke. It will be a big effort to put in the electrical infrastructure for it to work, I haven't been motivated to go through all the trouble without having the confidence that will fix the issue.

I hear you and yes, they start!
Now my 95 came from Europe with some deleted items because of the warm climate.
My glow screen was disconnected, I went momentary switching for cool days and a Webasto Bluetooth programmable heat for those -30 or colder days when you just need to start.
I have 3 Toyota diesels and they all smoke differently.
1hz
1hdt
Hd-ft
Sold my BJ74 and it was different as well. The glow system was great when the temp sensor was unplugged during those mediocre days when the weather was between rain and snow.
During heavy cold snaps there were no issues with the sensor plugged in.