Injection Pump timer cover leaking and loose (1 Viewer)

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Nov 20, 2005
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Location
Kootenays
Hi,

1990 1HZ

I had a cold start fuel drip in the winter and it went away with spring so I didn't worry about it too much.

It started leaking the first few cool nights of September and, soon after, I started hearing a funny rattle at about 1500 rpm. I put some bio in the fuel and the leaking went to almost nothing but the rattle continued.

Finally took the wheel off and had a good look at the Injection Pump and found the leak was coming from the RH (to the block) Timer Cover. I also found the rattle's coming from there as well. You can see (and feel) the cover shaking.

I don't want to take the pump off just to tighten two little allen bolts!! But I may have to do it to change out the o-ring though the bio seems to be working.

Questions:

1. Anyone had experience tightening those little bolts with the pump still on. I think one can be tightened but the other is real real tight to the block.

2. I have a very experienced mechanic, who's off hunting till mid October, who can help take the pump out. Should I worry too much about the thing falling off before that? Damage?

3. Would a little more bio (I'm running @B20) make a difference by swelling the o-ring and creating a better seal and possible damping the rattle?

Thanks!!

Michael
 
Rattling could be the timer piston slapping around. This chews the housing out. Even if its not the timer piston,rattling is loose metal and thats not good.Bio will not fix.
Your pump is 22 years old and its probably ready for a rebuild.
I think you will be removing the pump,prepare for $$$

Experienced mechanics are not fuel pump experts and that is what you need.
 
Rattling could be the timer piston slapping around. This chews the housing out. Even if its not the timer piston,rattling is loose metal and thats not good.Bio will not fix.
Your pump is 22 years old and its probably ready for a rebuild.
I think you will be removing the pump,prepare for $$$

Experienced mechanics are not fuel pump experts and that is what you need.

Thanks for the feedback. You may be right about the rebuild! 180k on the truck and run with additive since I've had it from 120k. The mechanic would be for pulling the pump and putting it back on. There is a good diesel shop in Cranbrook B.C. which does a lot of mine trucks if I have to get the pump rebuilt.

No drop in power since I've owned it and even lately with the rattle. I am going to try and tighten the cover (at least one side) and see what difference that makes to the rattle.

Michael
 
Good luck with it then,a 180kklms is not too much. You might be able to to loosen the flange bolts and rotate it to get access to the back side of the pump. Just make sure you have some marks so you can get it back to its normal spot.
 
My guess is you need a little O ring seal. Take the cover off and you will likely find an O ring that is brittle and cracked. You should be able to get a replacement at a heavy equiptment shop - especially places that service Asian diesel equiptment. Just take the old O ring with you to have them size it up. You can buy complete seal kits from diesel injection shops in Australia. I have an OEM <Zexel> kit from Hiflo and fixed the exact same leak on my wife's TD4.2 in about 5 minutes. I can access the plate from underneath without removing anything. The cost for the kit was about $18 but it took a few weeks to come snail mail. Our pumps are the same design - all Bosch VE.

On my otyher TD4.2, I had the same leak and took it to a local fuel injection shop where they got me to rebuild it. Their tech told me that the wear was minimal but they did replace a couple parts. The catch is they have to tear it apart to check for wear. It is definitely cheaper for you to take the IP off and put it on than pay an injection shop to do it. You may want them to then fine tune it, if it gets rebuilt. Although, if you have the timing tools, you can do it yourself.
 
My guess is you need a little O ring seal. Take the cover off and you will likely find an O ring that is brittle and cracked. You should be able to get a replacement at a heavy equiptment shop - especially places that service Asian diesel equiptment. Just take the old O ring with you to have them size it up. You can buy complete seal kits from diesel injection shops in Australia. I have an OEM <Zexel> kit from Hiflo and fixed the exact same leak on my wife's TD4.2 in about 5 minutes. I can access the plate from underneath without removing anything. The cost for the kit was about $18 but it took a few weeks to come snail mail. Our pumps are the same design - all Bosch VE.

On my otyher TD4.2, I had the same leak and took it to a local fuel injection shop where they got me to rebuild it. Their tech told me that the wear was minimal but they did replace a couple parts. The catch is they have to tear it apart to check for wear. It is definitely cheaper for you to take the IP off and put it on than pay an injection shop to do it. You may want them to then fine tune it, if it gets rebuilt. Although, if you have the timing tools, you can do it yourself.

Hi,

Thanks!

Looks like that might be the problem. Unfortunately getting access the back timer cover means pulling the pump. I can do that in about a month but what is causing the "rattle"???

No sound cold but once it heats up you get a high pitched vibrating sound between 1200 and 1600 rpm's. Then it's gone. When I put my finger on the back timer cover I can "feel" the vibrating but when I put my finger on the front cover or the timer spring adjust I feel a lot less vibration.

The truck is running great except for the weird sound.

Weird. It's a :bang: to get at the rear allen bolts but I will try again tomorrow.

I want to know whether I should drive it or park until I can get the pump pulled and the cover and o-ring replaced? When the pump is off I might as well get it looked at. It'll cost $$$ but what with the ULSD fuel I probably should get it done.
 
Hi,

Thanks!

Looks like that might be the problem. Unfortunately getting access the back timer cover means pulling the pump. I can do that in about a month but what is causing the "rattle"???

No sound cold but once it heats up you get a high pitched vibrating sound between 1200 and 1600 rpm's. Then it's gone. When I put my finger on the back timer cover I can "feel" the vibrating but when I put my finger on the front cover or the timer spring adjust I feel a lot less vibration.

The truck is running great except for the weird sound.

Weird. It's a :bang: to get at the rear allen bolts but I will try again tomorrow.

I want to know whether I should drive it or park until I can get the pump pulled and the cover and o-ring replaced? When the pump is off I might as well get it looked at. It'll cost $$$ but what with the ULSD fuel I probably should get it done.

The timer piston is behind those 2 covers which is why I suspect that is the problem.
The covers are called the timer piston covers.
If you have an FSM ,there is a picture on page FU44.

There is an adjusting screw on the inside of one of the covers,but whether that can stop the rattle ,I do not know.
 
The timer piston is behind those 2 covers which is why I suspect that is the problem.
The covers are called the timer piston covers.
If you have an FSM ,there is a picture on page FU44.

There is an adjusting screw on the inside of one of the covers,but whether that can stop the rattle ,I do not know.

Gotcha . . . funny thing though is when I get the rattle I can feel it through the back timer cover way more than the front (which is where the adjusting screw is).

I can see the Timer Adjusting Screw (FU-52) is preset to a range (7.5mm - 8mm) so maybe I can try "tightening" it closer to 7.5 mm???

Fun stuff.
 
Maybe it will work. When mine was rattling it required a whole new housing because the timer piston had worn it away. This is probably the danger if you keep using it while the rattle is there.

This is a pic although it doesnt show much.All those other parts had to be replaced as well and cost about $1800 inc the injectors I think.
I pulled it and put it back on myself

1HZPICS003.jpg
 
Maybe it will work. When mine was rattling it required a whole new housing because the timer piston had worn it away. This is probably the danger if you keep using it while the rattle is there.

This is a pic although it doesnt show much.All those other parts had to be replaced as well and cost about $1800 inc the injectors I think.
I pulled it and put it back on myself

Great feedback!

How long did you drive yours with the rattle? It's been about 200 kilometers for me.
 
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I tried tightening the timer adjusting screw up to two turns and the sound seemed to get worse.

So I tried backing off a turn (from the original setting) and the sound is definitely is a lot less.

Should I back off even more???? According the manual I am adjusting the piston timer stroke. Why would increasing the stroke help?

What the heck is happening in there? Weird.

I'm thinking that if the back timer cover is loose then loosening the tension on adjusting screw could be decreasing pressure/contact on the back cover so it doesn't vibrate as much . . . :hmm:

If the o-ring is going (thus the leaking fuel) then that will increase metal on metal contact with the back cover which is where the vibration is become noise.
 
:confused: Rosco, that head looks rusted. What happened?

It was off an engine that got immersed in very salty water in an underground mine.The mechanic refused to believe I had had the engine and pump working.
It wasnt beautiful ,but it started with a big dose of the ether bunny and then continued to run on diesel.
 
Great feedback!

How long did you drive yours with the rattle? It's been about 200 kilometers for me.

A couple of minutes.It was from a mine vehicle that I bought cheap with the intention of rebuilding it.
 
I tried tightening the timer adjusting screw up to two turns and the sound seemed to get worse.

So I tried backing off a turn (from the original setting) and the sound is definitely is a lot less.

Should I back off even more???? According the manual I am adjusting the piston timer stroke. Why would increasing the stroke help?

What the heck is happening in there? Weird.

I'm thinking that if the back timer cover is loose then loosening the tension on adjusting screw could be decreasing pressure/contact on the back cover so it doesn't vibrate as much . . . :hmm:

If the o-ring is going (thus the leaking fuel) then that will increase metal on metal contact with the back cover which is where the vibration is become noise.

Im not too clued up on this part of the pump.If the timer cover is that loose I would have thought the fuel would be pouring out.
 
Im not too clued up on this part of the pump.If the timer cover is that loose I would have thought the fuel would be pouring out.

Agreed on the pouring out thing. It was just dripping on cold startup.

How about backing the adjust screw off another turn or even more?

What are the implications of increasing the timer piston stroke?

I realize this is probably diesel shop stuff but thanks for any hints!

Michael
 
It was off an engine that got immersed in very salty water in an underground mine.The mechanic refused to believe I had had the engine and pump working.
It wasnt beautiful ,but it started with a big dose of the ether bunny and then continued to run on diesel.

:eek: I am with your mechanic on that one!
 
I really dont know.I wouldnt touch until you know more.

According to the manual:

"The hydraulic type timer installed in the lower part of the injection pump is operated by the fuel pressure of the pump housing, and movement of the roller ring by the timer advances the injection angle and controls the injection timing."

I don't think I can screw things up to badly!! If the timing is off then the truck won't run so well. I'll play with one more turn "loosening" the timer screw. But it will be a couple of days before I can back under the truck.

I will let you know how it goes.
 
According to the manual:

"The hydraulic type timer installed in the lower part of the injection pump is operated by the fuel pressure of the pump housing, and movement of the roller ring by the timer advances the injection angle and controls the injection timing."

I don't think I can screw things up to badly!! If the timing is off then the truck won't run so well. I'll play with one more turn "loosening" the timer screw. But it will be a couple of days before I can back under the truck.

I will let you know how it goes.

I think you can screw things up significantly. Your pump can be rendered unrebuildable, and a new one will cost you a lot.
If your timing is too far off you will end up with scuffed rod and main bearings in the engine quickly as well. Really not so brilliant and not worth it.
 

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