Dynamic timing mods (1 Viewer)

[4Ruster]

Hey all,

Since toyota uses the same bosch ve pumps as cummins and vw, I'm curious if anyone has adjusted the dynamic timing on your pumps, even installed a different spring or timing spacer?

I'm noticing a lot a black smoke on my n/a 2L and wondering if increasing my timing at higher loads will help. Right now I have the timing set right at the top of factory specification (yes I finally bought the proper timing dial gauge tool). Fuel screw is turned down pretty far. I don't want to lose any of my low end torque and I'm seeing all the cummins guys are adjusting the dynamic timing to get more out of it. Would this potentially help our engines or are they good enough with the stock piston length?

 

[mudgudgeon]

Hey all,

Since toyota uses the same bosch ve pumps as cummins and vw, I'm curious if anyone has adjusted the dynamic timing on your pumps, even installed a different spring or timing spacer?

I'm noticing a lot a black smoke on my n/a 2L and wondering if increasing my timing at higher loads will help. Right now I have the timing set right at the top of factory specification (yes I finally bought the proper timing dial gauge tool). Fuel screw is turned down pretty far. I don't want to lose any of my low end torque and I'm seeing all the cummins guys are adjusting the dynamic timing to get more out of it. Would this potentially help our engines or are they good enough with the stock piston length?

Short answer, yes.

Long answer, can of worms.

 

[KiwiDingo]

Yep, played and adjusted them lots with good success. Unsure how that will go with N/A engine though as I mainly used it to help bigger turbos

 

[4Ruster]

Yep, played and adjusted them lots with good success. Unsure how that will go with N/A engine though as I mainly used it to help bigger turbos

I’m getting a lot of injector rattle while cruising around 2000rpm, would adjusting it help with my issue?

 

[KiwiDingo]

I’m getting a lot of injector rattle while cruising around 2000rpm, would adjusting it help with my issue?

Yes it would, that's actually one of the reasons I started learning about the dynamic adjustment. Mine come back from a pump rebuild and it rattled at cruise which I didn't like.

 

[4Ruster]

Yes it would, that's actually one of the reasons I started learning about the dynamic adjustment. Mine come back from a pump rebuild and it rattled at cruise which I didn't like.

Oh no way. I want to learn everything I can about dynamic timing now. To start, should I add tension to the spring or remove tension? It has an adjuster hex on the cap and appears to be about halfway out.

 

[KiwiDingo]

Depends what you want to achieve? If you add preload to the spring by winding the adjuster in you delay the movement of the timing piston which moves as the pump case pressure rises with RPM. You'll find a point as you wind in where the light load / cruise engine rattle reduces. Depending on how the pump was calibrated it could be half a turn up to even 2-3 turns, but it really depends on current calibration especially what the case pressure regulator is set to.

 

[4Ruster]

Well I turned it in by one turn and wow what a difference. That rattle has gone down drastically and the truck still feels good.

 

[KiwiDingo]

Well I turned it in by one turn and wow what a difference. That rattle has gone down drastically and the truck still feels good.

It's amazing how much the engine can rattle when the timing isn't quite right. People think it's normal and put up with it but it drove me nuts. Most people don't take the time to fully setup there injector pump. They set the base / static timing and think it's all perfect but there's a lot more to it than that. I'm glad you tinkered and solved your issue

 

[4Ruster]

Yeah no kidding. 6 months ago I knew nothing about these pumps but since all the 'diesel' shops in my town only know how to plug a laptop into a truck I had to figure out everything myself. As soon as I starting driving I knew something was off. I may tinker with it later to see if I can get some more low end grunt, right now my biggest issue it the aggressive governor spring pulling the throttle back above 1500RPM, makes it really fun to drive. I might buy a 3200RPM spring that the cummins guys use and see if that helps me out.

 

[4Ruster]

Well turns out the halahala people who sold me the reman pump don't know what they're doing. I turned the adjuster in another turn and hit some resistance, lightbulb moment happened, the adjuster wasn't even touching the spring yet, no wonder it rattles like crazy. I turned it in to add a little tension and it feels normal again, no smoke on acceleration, and no injector hammering when pulling hard. Feels better in the low end but could still use some adjusting.

Never buy your pumps on ebay smh

 

[mudgudgeon]

I might buy a 3200RPM spring that the cummins guys use and see if that helps me out.

May not fit your pump.

The pumps are essentially the same. Cummins used Bosch VE Rotary pump. Toyota used a Denso VE Rotary pump, made by Denso under licence from Bosch.

They are essentially the same, but they have differences.
For example, the Cummins Bosch pump uses 12mm fuel rod in the compensator, Denso pump uses 10.9mm.

 

[4Ruster]

Here’s a video of me revving it. Seems to only blow smoke when I let off quickly, though when driving it does it when I give it a lot of throttle quickly, if I ease into it, I don’t get as much smoke, but I never had this issue before the rebuild. How do the injectors sound? This is warmed up so they’re 5x quieter then cold.

 

[Masha]

The motor/injector noise sounds pretty smooth in my opinion mate, little bit rattly abit above Idle but thats how my 1hz sounds at the moment and I think it goes pretty good.

Ive just been mucking with the dynamic timing screw tonight on my 1hz turbo, I turned the hex grub screw in a full turn to see if I can get better idle off or low end torque as my ute seems abit gutless taking off compered to other 1hz powered vehicles Ive driven.

To my way of thinking I suspect my pump is worn and doesnt produce enough fuel pressure at idle until revved up, so I think if I advance the static timing alot more than standard specs and then along with turning in the dynamic timing screw in (clockwise) to reduce the over all timing sweep when rpm is increase my motor should therefore have better idle off torque.

 

[JDM Journeys]

This all sounds familiar... My n/a 1hz has had a rattle since I got it 3 years ago, esp when cold. It comes on under load when I reach about 2k rpm.

Put brand new injectors in, and had pump gone through by a diesel specialist (they said it was in good shape at 280k kms, just needed seals etc). Set timing to 1.06 but had to advance it more by ear when running to smooth it out and clear the white smoke. Fuel is pretty leaned out but I live at 3600 feet.

So now no white smoke on startup, and almost no black, but the rattle under throttle is annoying. Quiets down quite a bit after about 20mins of warmup but never fully goes away...

Does this (long winded) explanation sound like a rattle that could potentially be muted by adjusting dynamic timing?



Cheers all...

 

[KiwiDingo]

Yes

 

[JDM Journeys]

So a quality evening spent with the Denso pump manual was interesting. It referred to the "load sensing timer" (sitting on same side but just below the ACSD), which I believe is the dynamic timing screw being referred to here?

I'm going to mark it and then make some incremental adjustments to try to reduce the rattle under load...

Appreciate the info from all of you in this thread. I've been trying to track down this rattle ever since I got this truck. Perhaps this is the key adjustment I've been missing? I'll follow up once I've tried it.