I dont want to railroad an awesome thread but I'd like to touch on the topic of fuel cooling via a fuel cooler of some sort.  I just have this crazy premonition that there needs to be a fuel cooler on these trucks.  Given what I recently experienced while towing a very large trailer in 100*+ weather uphill with the engine at 215*-220* and having the throttle do something unexpectedly weird, excessive fuel temps or just plain excessively hot PSG is becoming very likely the culprit of what happened.

 

I'm going to be digging into this topic really heavily and searching for an optimal small radiator to mount somewhere under or in front of the truck.  Possibly with a fan assist too.  There is just too many other trucks/diesel vehicles utilizing a diesel fuel cooler.

 

In saying that, I've wondered if anyone has ever considered trying to cool the PSG itself.  Chip from Bluechip told me around a year ago that Bosch has implemented thicker heat sinks under the PSG but I can’t confirm this and he's not around anymore.....that I know of.  Then I got to thinking about a Peltier Module.....  Why hasn’t this been considered?????  Maybe it couldn’t offset the heat dissipation needed but I think using a $20 Peltier Module and sticking an aluminum bladed computer CPU heat sink to the top of it would have to help.  Here's a video of what this device is if someone doesn’t understand what I'm talking about. https://www.youtube.com/watch?v=9Cuh2msd2lo If someone was so inclined they could install an inline thermostat too so it didn’t run in the winter.

 

Maybe this would be better served in another thread but I think its a topic which needs to be revisited again.....

Unless I am a goof (very possible) the diesel fuel is not much for heat transfer compared to the aluminum or whatever alloy the pump is made out of.

Nice work there Ed.

 Chris

Nice work Ed.  I'll be reading up.....

 

On another note, like I mentioned before, there's considerable effort in the European and Spanish folks whereby they've dealt with the PSG and transistor I think way more than we have over here.  Matter of a fact, just for sake of the thread, here's a picture of someone who actually tried to shade tree fix the PSG and a link to another foreign thread http://www.forum-auto.com/pole-technique/mecanique-electronique/sujet537674-35.htm where they're experimenting with soldering in the circuits and replacing parts.  I cant read the language but if anyone's bilingual then maybe you can make out what they're doing or even if it worked.

 

But back to my "theory" about simple electrical strain or surges placed on the PSG, you'll notice that the high pressure solenoid and the timing solenoid both connect to the PSG right at the transistor.  Coincidence?.....not sure.  But below is a couple more web pages with some interesting info regarding Pb free solder and how it reacts to heat, contraction, expansion, and surface warping. http://product.tdk.com/en/techjournal/archives/vol05_mlcc/contents06.html  I found it interesting but still not understanding why the main failure of the PSG is the transistor.....

OK,   so  'transistor'      (transformer-resistor)  correct??

 

Here you go..

http://en.wikipedia.org/wiki/Transistor

 

Transistor as a switch

Transistors are commonly used as electronic switches, both for high-power applications such as switched-mode power supplies and for low-power applications such as logic gates.

In a grounded-emitter transistor circuit, such as the light-switch circuit shown, as the base voltage rises, the emitter and collector currents rise exponentially. The collector voltage drops because of reduced resistance from collector to emitter. If the voltage difference between the collector and emitter were zero (or near zero), the collector current would be limited only by the load resistance (light bulb) and the supply voltage. This is called saturation because current is flowing from collector to emitter freely. When saturated, the switch is said to be on.^[29]

Providing sufficient base drive current is a key problem in the use of bipolar transistors as switches. The transistor provides current gain, allowing a relatively large current in the collector to be switched by a much smaller current into the base terminal. The ratio of these currents varies depending on the type of transistor, and even for a particular type, varies depending on the collector current. In the example light-switch circuit shown, the resistor is chosen to provide enough base current to ensure the transistor will be saturated.

In any switching circuit, values of input voltage would be chosen such that the output is either completely off,^[30] or completely on. The transistor is acting as a switch, and this type of operation is common in digital circuits where only "on" and "off" values are relevant.

I would be willing to bet that what they are calling a transistor is actually a MOSFET.

 

Ed

This thread reminds me of a problem I had with a Sea Ray Cabin cruiser I used to own.  The fuel would get hot and vapor lock.  The boat had a 110 gallon tank and even that was not enough to keep the fuel cool enough on really hot days with that 454 running hard.  What I finally did was to buy a Moroso Insultated Cool Can.  The concept was pretty simple.  The can held a good bit of ice and was well insulated. the ice would last about 4 hours give or take.  Once the ice melted enough to create a liquid chilled bath around the fuel heat exchanger, maximum cooling was achieved.  Once I installed the cool can, I never had another problem.  I did not use is all the time, only when it was really hot and humid.  

 

I would think this might be a very cheap and VERY simple alternative for cooling the diesel fuel right before it goes into the VP-44.  During cool times of the year, you don't fill it with ice and just run the engine like it is not there as it is plumbed into the fuel system. 

 

Probably not what you guys are thinking of but I figured I would throw it out there.  Simple is better in my book. 

 

http://www.jegs.com/i/Moroso/710/65125/10002/-1

Edited August 21, 201410 yr by LiveOak

Thanks Mike,  So,  in a roundabout way,   the  schematic shown  is    kinda like a   relay...  but in this  case,   it is  using  voltage differential  in  one  circuit  (if it  goes up or down)   to   either  open or close the switch  for another.

 

 

Man,   I  can almost  'see'  what  dirty  AC  would  do here!     Poor little  dude  going  beyond the call of duty!   Instead of  smooth  DC,  it'd be  hammered  with  mixed  signal  AC  dirty..   the  field  would  be  building, collapsing,  and  rebuilding at the rate of  the  'noise'..    gotta be a  heat builder for sure!

Edited August 21, 201410 yr by rancherman

 

Nice find...  does this mean  that  little  thing is  driving both  the  timing AND  fuel solenoid?

I would be willing to bet that what they are calling a transistor is actually a MOSFET.

 

Ed

 

Here is what Ed is talking about...

http://en.wikipedia.org/wiki/MOSFET

 

even the russians have the issue, check this out...

 

http://forum.opelclub-by.com/index.php?showtopic=20908&mode=linearplus

 

look at the nice close ups they took, the wire lead is melted into a pool and the transistor is deformed...

 

i think they took the pic from elsewhere. but still that thing is getting a high heat load from something to melt wire leads.

Edited August 21, 201410 yr by CUMMINSDIESELPWR

i guess one would be inclined to take voltage readings from the pins on a working vp44 and see what the load is, if possible...

Edited August 21, 201410 yr by CUMMINSDIESELPWR

http://www.drive2.ru/l/288230376152567844/#post

http://www.drive2.ru/l/288230376152567844/#post

If this works here is a Google translation for that site. https://translate.google.com/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.drive2.ru%2Fl%2F288230376152567844%2F%23post&edit-text=&act=url

Nice work Ed.  I'll be reading up.....

 

On another note, like I mentioned before, there's considerable effort in the European and Spanish folks whereby they've dealt with the PSG and transistor I think way more than we have over here.  Matter of a fact, just for sake of the thread, here's a picture of someone who actually tried to shade tree fix the PSG and a link to another foreign thread http://www.forum-auto.com/pole-technique/mecanique-electronique/sujet537674-35.htm where they're experimenting with soldering in the circuits and replacing parts.  I cant read the language but if anyone's bilingual then maybe you can make out what they're doing or even if it worked.

 

 

Here is the Google translation for this site: https://translate.google.com/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.forum-auto.com%2Fpole-technique%2Fmecanique-electronique%2Fsujet537674-35.htm&edit-text=&act=url

thanks man!

 

Thanks for the video!

so my theory is, the transistor is a switch of higher voltage via a low voltage input signal.  whatever the load is being put through the high side of the transistor is either too great or the ability of heat dissipation is too small. Remember the thermal load on this little guy is wafer thin stuck on a big block of HOT metal, the heat generated has nowhere to go except in its small thermal footprint and "poof"...

 

Or there are voltage surges spiking after time that finally put it 6' under.

 

or an AC voltage erroneously hits and poof...

 

or gremlins...?

Just thinking outside the box here...if it is an AC pulse that kills the little guy.

Would it be possible to to put a small diode  (think thats the name) in the power supply for the PSG.

Or are there a bunch of wires that supply current. I do know that part of my checks were battery voltage to 1 wire, not sure about the others in the harness there.

Regards Chris

Just thinking outside the box here...if it is an AC pulse that kills the little guy.

Would it be possible to to put a small diode  (think thats the name) in the power supply for the PSG.

Or are there a bunch of wires that supply current. I do know that part of my checks were battery voltage to 1 wire, not sure about the others in the harness there.

Regards Chris

 

Just like putting a noise filter on the PCM for torque converter lockup issues. Now you have protected the PCM or VP44 but now the other devices take the AC noise as well. Remember its just easier to keep a clean alternator than to attempt to filter every single device and prevent AC noise introduction. Again I'm on the home stretch of 200k on this pump. No other device issues either.

 

It would be easier to just remove the alternator and then there is no more AC noise issues period. Pure DC power solely from the batteries.

My thoughts were to put the diode in but still check the alternator ( using your test ) once in a while.

Just a little extra protection.

I would never have thought about checking an alternator for AC.

But now that I read about it here it makes perfect sense, an alternator makes AC first and then its turned into the DC our trucks use. 

We still don't know if the AC pulse will kill it or even how much and for how long.

I would think that it dosen't take much and not for long either.

 Still learning and still asking questions.

Chris