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

[roscoFJ73]

No, I haven't. How is it accessed?

There is usually an access plate in the rear so you can disconnect the fuel pick up on top of the tank and remove it. But what I would do is set up a small container of fuel and connect it to the injector pump. If it works fine, the problem is further back, possibly a blocked pick up. If it doesn't work well, it maybe in the pump.
This might be easier than pulling the fuel pick up out. You can also empty the tank through the bung at the lowest point and look inside, but I'm not sure if you can see the pick up. Probably could with a small mirror.

 

[Dave 2000]

Bacteria can grow in diesel tanks and the blocked pick up pipe strainer is a common problem.

Remove the centre row of seats assuming you have all three rows and lift the carpet. You will see an oval plate secured with small bolts/screws. Remove that and this exposes the fuel tank.

Disconnect the pipes and the cables for fuel level and low fuel warning. Remove the set of screws and the unit simply lifts out. On the end of the pipe is a plastic filter, this slides off of the pipe and you simply clean it out and put back in.

Get a decent torch and shine it into the tank and look for any contamination, if you see any simply set up a siphon with a small tube and you can vacuum the bottom of the tank clearing any debris.

Reassemble in reverse order, and note you do not have to drain the tank, or get under the vehicle. Being diesel it is not as dangerous as an open petrol tank but stay cautious anyway.

This is a simple job and will take around an hour and a half.

Regards

Dave

 

[Turbobrick211]

Bacteria can grow in diesel tanks and the blocked pick up pipe strainer is a common problem.

Remove the centre row of seats assuming you have all three rows and lift the carpet. You will see an oval plate secured with small bolts/screws. Remove that and this exposes the fuel tank.

Disconnect the pipes and the cables for fuel level and low fuel warning. Remove the set of screws and the unit simply lifts out. On the end of the pipe is a plastic filter, this slide off of the pipe and you simply clean it out and put back in.

Get a decent torch and shine it into the tank and look for any contamination, if you see any simply set up a siphon with a small tube and you can vacuum the bottom of the tank clearing any debris.

Reassemble in reverse order, and note you do not have to drain the tank, or get under the vehicle. Being diesel it is not as dangerous as an open petrol tank but stay cautious anyway.

Regards

Dave

Hey Dave.

This is great advice. I will definitely give this a look next weekend. Thank you for such clear instructions. I'll report back what I find. I'm also pulling the top off the IP this weekend to replace some leaking seals and check on all the springs.

 

[Dave 2000]

Hey Dave.

This is great advice. I will definitely give this a look next weekend. Thank you for such clear instructions. I'll report back what I find. I'm also pulling the top off the IP this weekend to replace some leaking seals and check on all the springs.

Your welcome.

Not having read through the entire thread I did not realize you had a leaking pump. Could this have been the trouble all along? Cleaning the tank filter is good PM either way as it is so simple.

If you are not mechanically minded I would be wary of taking the pump apart.

Regards

Dave

 

[roscoFJ73]

Get a decent torch and shine it into the tank

You should be careful, americans and canadians think you are telling them to point a flame thrower into the tank.

 

[Turbobrick211]

Your welcome.

Not having read through the entire thread I did not realize you had a leaking pump. Could this have been the trouble all along? Cleaning the tank filter is good PM either way as it is so simple.

If you are not mechanically minded I would be wary of taking the pump apart.

Regards

Dave

I will say I have never cracked open an injector pump.

You should be careful, americans and canadians think you are telling them to point a flame thrower into the tank.

Lol. Yeah, that's pretty good. I was feeling pretty good about not blasting an oxy torch into the fuel tank. But good call.

And Dave 2000, thanks for the advice. I'm pretty mechanically minded. I owned a Volvo race shop for a decade, have built hundreds of engines, am a certified welder/fabricator, and now I work at Blue Origin Aerospace building huge rockets. However, injector pumps are on par with rocket engines in complexity.

 

[Dave 2000]

I will say I have never cracked open an injector pump.

Lol. Yeah, that's pretty good. I was feeling pretty good about not blasting an oxy torch into the fuel tank. But good call.

And Dave 2000, thanks for the advice. I'm pretty mechanically minded. I owned a Volvo race shop for a decade, have built hundreds of engines, am a certified welder/fabricator, and now I work at Blue Origin Aerospace building huge rockets. However, injector pumps are on par with rocket engines in complexity.

The actual amount of tiny bits and pieces inside these pumps has to be seen to be believed for sure,

Regards

Dave

 

[Turbobrick211]

The actual amount of tiny bits and pieces inside these pumps has to be seen to be believed for sure,

Regards

Dave

Yeah, I was watching a video of a guy in Indonesia dismantle and clean an IP, and he had a huge table completely covered in parts. It is shocking.

 

[Turbobrick211]

Yeah, I was watching a video of a guy in Indonesia dismantle and clean an IP, and he had a huge table completely covered in parts. It is shocking.

Update. So I've been messing with the truck tonight. I tried turning up the main fuel screw, and it seems to not change the idle at all. However, when I rev it up, it revs much faster and blasts out black smoke! I'm not surprised by this, but I feel like it is leading me to a broken spring inside the IP. I have also tried tightening up the idle arm rod, to no avail. It still drops down and dies. As a side note, the IP is not leaking that badly, and I have a clear hose between the filter housing and the IP, and air is not reaching the IP. Please help. I plan to pull the top of the injector pump on Friday. I kind of hope to find a broken spring, however, I don't have any new springs to replace it with.

 

[roscoFJ73]

but I feel like it is leading me to a broken spring inside the IP

From my limited experience, they usually stretch rather than break. We've had a few do that on this forum, but one guy disappeared after the Haitian earthquake and I forget about the others. I remember their 1HD T's ran worse pointing uphill. I cant even remember if I told you that before.

 

[Turbobrick211]

From my limited experience, they usually stretch rather than break. We've had a few do that on this forum, but one guy disappeared after the Haitian earthquake and I forget about the others. I remember their 1HD T's ran worse pointing uphill. I cant even remember if I told you that before.

Okay, that makes sense. I remember reading about them running worse pointing up hill. I haven't noticed that problem, but then again maybe I haven't been on a steep enough hill. Well, wish me luck! I'm going to dig into it tomorrow morning and see what I can find. I'm hoping a local injector pump shop will have the springs available.

 

[AirheadNut]

If it turns out to be an issue inside the IP I would recommend just having it rebuilt professionally. Diesel Fuel Injection Service in Portland OR has done a bunch of them and has competitive pricing. @SnowVersion had his done there and it came back looking brand new. The engine runs much better now too.

 

[roscoFJ73]

I'm hoping a local injector pump shop will have the springs available.

They wont, they will order them in from Denso. Look for shops that display a Denso/Bosch sign somewhere. These pumps are fundamentally the same as VW pumps.
Dont get fixated on governor springs, keep an open mind.
Send the pump to someone with a proven record on MUD as Airhead suggested
If you find someone local, ask them to bench test it before stripping it down and ask for detailed explanation.

 

[Turbobrick211]

If it turns out to be an issue inside the IP I would recommend just having it rebuilt professionally. Diesel Fuel Injection Service in Portland OR has done a bunch of them and has competitive pricing. @SnowVersion had his done there and it came back looking brand new. The engine runs much better now too.

Hah, that's funny. My old shop was literally right next door to Diesel Fuel Injection Service. Those guys know me well. I took injectors and turbos over there all the time to get rebuilt.

 

[SnowVersion]

I just had the IP and injectors for my 1HDT rebuilt by DFIS in Portland and couldn't be more pleased with the work they performed. My IP was pretty tired and had started to leak. Now the truck has much improved power and throttle response. Additionally, the pump came back sparkling clean.


Here's a before shot:

And here's after DFIS was done with it:

 

[Turbobrick211]

Update! It's fixed! However, I think a pump rebuild will be in the near future. I did a ton of work to the truck yesterday. Replaced all the coolant hoses and flushed the cooling system and replaced the t-stat. Pulled the intake manifold and injector lines to replace the leaking manifold gaskets. Replaced as many of the injector pump seals I could access. Pulled off the ACSD, and I believe that was the problem. When I removed the nut on the shaft, to pull the spring off to get to the 5mm Allen, the shaft slid right out and was broken on the end. My heart sank to my stomach, because I thought that i broke it, and now a piece was floating around in the pump. I pulled the acsd off, and found the broken part just sitting there. Upon inspection, I realized that the tab had been broken off the shaft for quite a while, and had been rattling around in there. It is quite beat up. I cleaned everything as best as I could, and out the delete kit on. Also checked out the governor spring, and it might be a little stretched out, but nothing crazy. I can compress it ever so slightly. After reassembling everything and priming the pump, it fired up but didn't idle. I adjusted the idle screw up a little, and it fired right up and idles!!! I gently turned the main fuel screw, checked for leaks and took it for a spin. The thing runs great, and idles like it should. And it has quite a bit more pep with the fuel screw adjusted a little. I'm still waiting for the filter/primer housing, which should be here tomorrow. But I am very pleased, and very thankful for all the help and guidance. We got about a foot of snow here yesterday, so I took it out and tried out the triple lockers. Oh my, this thing is a beast. So much fun. I'll post some pics of the broken shaft. Very interesting.

 

[roscoFJ73]

I can compress it ever so slightly

Thats how they are. They expand and contract with centrifugal force.

 

[Dave 2000]

Update! It's fixed! However, I think a pump rebuild will be in the near future. I did a ton of work to the truck yesterday. Replaced all the coolant hoses and flushed the cooling system and replaced the t-stat. Pulled the intake manifold and injector lines to replace the leaking manifold gaskets. Replaced as many of the injector pump seals I could access. Pulled off the ACSD, and I believe that was the problem. When I removed the nut on the shaft, to pull the spring off to get to the 5mm Allen, the shaft slid right out and was broken on the end. My heart sank to my stomach, because I thought that i broke it, and now a piece was floating around in the pump. I pulled the acsd off, and found the broken part just sitting there. Upon inspection, I realized that the tab had been broken off the shaft for quite a while, and had been rattling around in there. It is quite beat up. I cleaned everything as best as I could, and out the delete kit on. Also checked out the governor spring, and it might be a little stretched out, but nothing crazy. I can compress it ever so slightly. After reassembling everything and priming the pump, it fired up but didn't idle. I adjusted the idle screw up a little, and it fired right up and idles!!! I gently turned the main fuel screw, checked for leaks and took it for a spin. The thing runs great, and idles like it should. And it has quite a bit more pep with the fuel screw adjusted a little. I'm still waiting for the filter/primer housing, which should be here tomorrow. But I am very pleased, and very thankful for all the help and guidance. We got about a foot of snow here yesterday, so I took it out and tried out the triple lockers. Oh my, this thing is a beast. So much fun. I'll post some pics of the broken shaft. Very interesting.

I advocated removing the ASCD around six years ago, this was because of a part breaking off ftom the ACSD had bern identified as damaging the pump. The slower idle when pointing uphill and again idling fast when pointed downhill was identified as a weak spring on the governor by a MUD member, I haven't done anything to address this in the ten years I have had the 80 as it is of little importance.

Regards

Dave

 

[kendrick]

Thinking I might be having a similar issue with air in my lines. When I prime the fuel it goes hard for a sec then pressure is releasing somewhere. I don.t see any fuel leaks of any sort though? Thoughts?

 

[roscoFJ73]

Its not meant to stay hard. The fuel injection pump is full and excess fuel is probably going out the fuel return. The hand primer is only there to draw fuel from the tank and fill the injection pump up.