VP Dynamic Timing Vs. Advancing

Is everything between the VP and ECM, PWM? Or is it just a simple 5v circuit that varies voltage signal to change what the ECM is reading and how it is telling the VP to compensate. If its just a 5v circuit, does anyone know which wire is the VP timing signal to the ECM? I'm thinking that there must be some way to just fool the ECM into thinking that timing is fine, and not reading the real base timing.
Sean
 
Ok, so far this is what I have for the VP diagram. I'm wondering if the fuel injection pump sync signal is the one to look into. That would be my best guess, but I'm not really sure. Its wire number 3, which is the 4th one from the left, and labeled as DG (Dark Green I'm assuming).

Vpdiagram.gif

Sean
 
I also found this. Still no sign if the sync does the timing or not though. There are also the Data link CAN connectors, which I'm going to guess are PWM so that may be where the timing issue is. I may try and throw a multimeter on the Injection pump sync wire and see if it changes when the timing is changed, also see if it is standard voltage, or PWM.
Vpdiagrams2.gif

Sean
 
The Data link CAN is what does the timing according to Quad when I was talking to him!

I think someone would have already come up with a way to interrupt and advance! It didn't work hence the reason why we have no option!
 
Thats kind of what I was afraid of. Simple 5v stuff I can work with. When it comes to PWM I am at a total loss, I barely understand how it works so its not something I want to mess with. The fact that it is called a sync though, is what has sparked my interest. Seems like even if it is pulse width modulated, there should be a way to mess with it. Whether, its through internal programming like an added feature on smarty, or if it is through an external module.
Sean
 
Another link on the VP44. This is an old link, so I'm sure many of you have already seen it. But it may help to offer a little insight into the function of the VP. It does talk about timing function and internal systems that allow the ECM to compensate for discrepancies between engine or cam position and VP position.

The way I see it, is timing helps on every other truck, 12v, or CR, so I don't see why it wouldn't help on a VP, the problem is just getting it to work right.

anyways, here is the link.
VP44 Electronic Inj Pump
Sean
 
Okay, so in my searching, I found that the VP timing sensor, which is noted multiple places as an IAT (which is a different IAT than the intake air temp), sends signals to the ECM in a simple square wave form. I also found a square wave generator, for $0.95 that can be made variable through the use of a potentiometer. So it may be viable to make a cheap little box that will just fool the ECM's signal into thinking everything is okay.
Sean
 
sstockton said:
Okay, so in my searching, I found that the VP timing sensor, which is noted multiple places as an IAT (which is a different IAT than the intake air temp), sends signals to the ECM in a simple square wave form. I also found a square wave generator, for $0.95 that can be made variable through the use of a potentiometer. So it may be viable to make a cheap little box that will just fool the ECM's signal into thinking everything is okay.
Sean
Click to expand...

Good find! I had a injection pump fail once throwing nothing, but a PO253 code. Brady told me that PO253 links to the IAT inside of the injection pump. That truck did all kinds of freaky stuff, not sure I'd be messing with that circuit.
 
Yeah, I'm going to start by tearing into a pump that I have sitting on a shelf and seeing what I can figure out. See if there is a way to figure exactly which wire I would need to check. Then when timing is normal, see if I can pick up a signal and find out the frequency and range of the signal. After that, it would just be trying to duplicate it on the bench with a square wave generator before I even thought about trying it on the truck. Honestly, it will probably be a while before I make any developments into that. So for now, I'm just trying to get people thinking on this, and waiting to see what the redline really delivers.
Sean
 
sstockton said:
Yeah, I'm going to start by tearing into a pump that I have sitting on a shelf and seeing what I can figure out. See if there is a way to figure exactly which wire I would need to check. Then when timing is normal, see if I can pick up a signal and find out the frequency and range of the signal. After that, it would just be trying to duplicate it on the bench with a square wave generator before I even thought about trying it on the truck. Honestly, it will probably be a while before I make any developments into that. So for now, I'm just trying to get people thinking on this, and waiting to see what the redline really delivers.
Sean
Click to expand...

I'm hoping to see the Redline tomorrow or Friday. I will give feedback, but I'm not getting my hopes up too much now.
 
Yeah, I hear ya. These are turning out to be tricky little buggers. We'll see what happens. A timing light is going to be necessary too.
Sean
 
When you tear into the pump, take a look at how the timing is advanced and if there is a way to modify the pump to get another 5-10 degrees of advance, if this is doable, then all you need to do is figure out a way to take control of the advance circuit. This would be a win win for the vp trucks
 
Read the following with this in mind, this is all based on how I understand the pump to operate, and I could well be wrong.

The internal timing advance/retard on the VP is handled by a solenoid that locks/unlocks the timing adjustments internal to the pump. This timing setup only has a certain range of motion possible to it, and with the limits of case size can only be so big. As an aside, low fuel pressure/starvation causes this doohickey to slam around, galling internal parts, hence the death code of "Internal Timing Advance Failure", the internals of these pumps are VERY close tolerance. Now, commanding max timing advance internal to the pump is a matter of feeding the correct signal to the pump control circuits, no more, this has been accomplished for years through the various boxes available since 01 and earlier. What ya'll are trying to do is trick the VP into giving less timing below 2k to help negate the effect of the mechanical advance of the pump gear. You cannot squeeze blood from a turnip, the pump can only compensate so much, and a full tooth or two is beyond the pump's internal limits. There is a reason proper timing for stock is done via key on shaft, small change, pump can adapt the rest internally.

Now, the adjustable gear that Weston mentioned earlier? That was built in an attempt to try out the various combos of gear/pump relationship to get the max timing possible at RPM and still keep the truck drivable on the street. Didn't pan out, why? Once you advance the pump gear so much, the pump simply cannot compensate internally, so you wind up with your timing well advanced over where it's needed lower in the RPM band.


All that said, if you build a custom cover that will allow you quick access to the pump gear, and have built a custom gear that you can dial in changes on quickly, there is no reason that for pulling or racing you can't have more timing advance than possible with a stock setup. The flip side is that you will be returning it close to stock to drive home, and in a race application you also run the risk of the truck falling off the charger by loosing to many RPM. With the improved boxes out today the higher RPMs are becoming feasible so this might well be worth looking into further now than it was several years ago. Pump electronics have improved across the board and might be able to "keep up" above 4K as that was one of the limiting factors earlier, the pump just couldn't keep up with the motor.

I'm not trying to knock anyone's efforts here, just relaying what little I know on the subject and trying to help with a voice of experience in the VP trucks and what has transpired before. Hopefully with the newer electronics a workable solution can be found, but from what I have seen, there is only so much available with mechanical means for performance apps without crappy trade offs on the street.
 
Billysgoat said:
Read the following with this in mind, this is all based on how I understand the pump to operate, and I could well be wrong.

The internal timing advance/retard on the VP is handled by a solenoid that locks/unlocks the timing adjustments internal to the pump. This timing setup only has a certain range of motion possible to it, and with the limits of case size can only be so big. As an aside, low fuel pressure/starvation causes this doohickey to slam around, galling internal parts, hence the death code of "Internal Timing Advance Failure", the internals of these pumps are VERY close tolerance. Now, commanding max timing advance internal to the pump is a matter of feeding the correct signal to the pump control circuits, no more, this has been accomplished for years through the various boxes available since 01 and earlier. What ya'll are trying to do is trick the VP into giving less timing below 2k to help negate the effect of the mechanical advance of the pump gear. You cannot squeeze blood from a turnip, the pump can only compensate so much, and a full tooth or two is beyond the pump's internal limits. There is a reason proper timing for stock is done via key on shaft, small change, pump can adapt the rest internally.

Now, the adjustable gear that Weston mentioned earlier? That was built in an attempt to try out the various combos of gear/pump relationship to get the max timing possible at RPM and still keep the truck drivable on the street. Didn't pan out, why? Once you advance the pump gear so much, the pump simply cannot compensate internally, so you wind up with your timing well advanced over where it's needed lower in the RPM band.


All that said, if you build a custom cover that will allow you quick access to the pump gear, and have built a custom gear that you can dial in changes on quickly, there is no reason that for pulling or racing you can't have more timing advance than possible with a stock setup. The flip side is that you will be returning it close to stock to drive home, and in a race application you also run the risk of the truck falling off the charger by loosing to many RPM. With the improved boxes out today the higher RPMs are becoming feasible so this might well be worth looking into further now than it was several years ago. Pump electronics have improved across the board and might be able to "keep up" above 4K as that was one of the limiting factors earlier, the pump just couldn't keep up with the motor.

I'm not trying to knock anyone's efforts here, just relaying what little I know on the subject and trying to help with a voice of experience in the VP trucks and what has transpired before. Hopefully with the newer electronics a workable solution can be found, but from what I have seen, there is only so much available with mechanical means for performance apps without crappy trade offs on the street.
Click to expand...

Thank you very much for all of your info. Every little bit helps improve the effort.
 
Thank you very much for the input Billy. My understanding, is that, without taking over the ECM or electronic controls, the pump won't reach full internal advance, so that max advance reached is still where it should be in relation to engine TDC. Whether or not it can keep up with a 5*+ advance I'm not sure of.

From what I can tell from looking at the pump this far, is that the timing solenoid, is probably controlled similarly to the fuel solenoid by the Pump's ECU. This may mean, that it can be over ridden via a wire tap (similar to the fuel solenoid) to help achieve maximum timing when the pump's electronic's are telling it to retard because of mechanical advance.

The part of that that worries me, is the IAT sensor. If the solenoid was over ridding the signal from the pump's ecu, and timing was beyond the commanded level, then it may throw a code. So there may be some call to return a fake signal to the ECM.

Ideally, a new square wave signal would be generated, to trick the ECM into commanding full advance, and letting the pump exceed the total advance that it is supposed achieve. And even better would be to set up the signal generator to be triggered by the Tach signal, so that it would only kick in after a certain desired RPM.
Sean
 
sstockton said:
Thank you very much for the input Billy. My understanding, is that, without taking over the ECM or electronic controls, the pump won't reach full internal advance, so that max advance reached is still where it should be in relation to engine TDC. Whether or not it can keep up with a 5*+ advance I'm not sure of.

From what I can tell from looking at the pump this far, is that the timing solenoid, is probably controlled similarly to the fuel solenoid by the Pump's ECU. This may mean, that it can be over ridden via a wire tap (similar to the fuel solenoid) to help achieve maximum timing when the pump's electronic's are telling it to retard because of mechanical advance.

The part of that that worries me, is the IAT sensor. If the solenoid was over ridding the signal from the pump's ecu, and timing was beyond the commanded level, then it may throw a code. So there may be some call to return a fake signal to the ECM.

Ideally, a new square wave signal would be generated, to trick the ECM into commanding full advance, and letting the pump exceed the total advance that it is supposed achieve. And even better would be to set up the signal generator to be triggered by the Tach signal, so that it would only kick in after a certain desired RPM.
Sean
Click to expand...


Hope it helps.

As for the timing internal to the pump, that is nothing more than telling one of the two solenoids in the pump to open or close, my understanding is that the boxes already on the market can command full timing advance. What I feel is going to be the baby killer for this is getting enough timing retardation out of the pump's internals to compensate for the mechanical advance via gear.
 
Billysgoat said:
Hope it helps.

As for the timing internal to the pump, that is nothing more than telling one of the two solenoids in the pump to open or close, my understanding is that the boxes already on the market can command full timing advance. What I feel is going to be the baby killer for this is getting enough timing retardation out of the pump's internals to compensate for the mechanical advance via gear.
Click to expand...

The Adrenaline/Smarty really help it alot, but still can only spool at 2k rpm.
 
I need to send my redline back. I have the unlimited tune but I don't feel that I get near the rpm that I should out of it. Here's a pic from one of the last pulls I made and checked the recall button.
 

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