Engine/Transmission (1998.5 - 2002) P1688 code on VP44 - what's the cause?

[DToy]

Yep, add me to the list of failed injection pumps. Mine went out on New Year's Eve - truck stopped dead a block away from my house. The code I am getting is P1688 which is the Injection Pump Controller. My question is this: What causes the injection pump controller to go out? My lift pump is still working and pushing 12-14 psi at idle. It seems to me that low pressure or no pressure would not cause the pump electronics to get toasted. From what I've read and been told there is no way to replace just the pump controller either. The worst part is that my 5 year/100K warranty expired as of 2 months ago, even though my truck only has 98K on the clicker.



Best part is that the dealer wants $2000 just for the pump. I found an independent shop locally that will replace it for $1350 installed. Gotta love the dealers!

 

[DToy]

So nobody knows what causes the electronics in the pumps to fail huh? First thing I did when I bought the truck was put a fuel pressure gauge in it, but it didn't protect the piece of junk VP44 from dying. Guess I'll replace it and roll the dice on toasting another one.

 

[GKinney]

toast

Well I can't tell you for sure what smokes 'em... . but I know I had the same code and experience with mine... . only I was about a mile from home. What a bummer..... it was a HOT day... I was throttling through the gears... when I started out in 4th... . it just went... ... gone!!! It sux... . then I read where some of the earlier pumps where only good for about 50k mi. But then I have read where people have over 150k with the stock pump. Go figure. I do know that any mods... ... boxes etc. will shorten their life, especially if you are running stock injectors... guess it creates too much strain on the pump with the added fuel with no where to go. That is why after I smoked mine last July... I took my EZ off until I get some bigger injectors. Well I hope this helps make the pain a little easier... ... . I know I wish I had one of my older rigs with the p7100 Too!!!!!

 

[Jeff Knight]

Larger injector don't always help. I have Bullydog 2's in my truck and the Comp still fried my VP44. I no longer have the Comp box. It runs fine with just the injectors. Jeff

 

[Gary - K7GLD]

The electronics in a pump controller aren't really all that much better than what's inside a $1. 98 transistor radio - and a failed 5 cent resistor will put ya on the shoulder of the road just as effectively as a busted crankshaft!

 

[DToy]

So what you guys are saying is that a comp, ez, etc. is to blame for frying the pump controller? Anyone else agree with this or have the same problem? I have an edge comp on my truck, but without the pump wire hooked up. It's been on for over 30,000 miles and no problem until now. I was planning on hooking up the pump wire on the new VP44, but I will not be replacing injectors right now. Is this going to fry my new VP44? I never saw or heard anything about it when I bought my comp. No warnings from Edge saying not to use it with stock injectors.

 

[Turbo Tim 1]

I put my comp on when the truck had 42,339 miles and I now have 113,756 miles, I never shut the comp off, it spent a good portion of the first year on 5x5, sometimes it's on 2x3 especially in the warmer months, right now it's on 3x5 and has been there for a couple of months. The early VP's were definantely more prone to dying from having boxes put on but I believe that was more of a mechanical thing and if your electronics died... ... haven't you ever had a tv or radio die, that's just what they do. You either want the extra power or you don't, anything that you do to add power is shortening the life of something on your truck, if that's a problem stay stock. My VE pump on my 93 went at around 120k and it was stock so if my VP dies now I won't feel that bad. I would rather spend the money on other add-ons but oh well.

 

[justinp20012500]

I have a 3 wire blue box tapped on my pump. It went for 55,000 miles with out a hiccup. I changed it because it was easy to get to when I fire ringed the head.

It's a fallacy regarding the bigger injectors releave stress on the VP.

The injectors are set to "pop off", or let fuel in the cylinder at a certain pressure.

If the injector has been made bigger by extrude hone or EDM or what ever, the vp still has to build the same pressure but now with more volume of fuel to get that cylinder to fire.


Justin-

 

[DToy]

haven't you ever had a tv or radio die, that's just what they do. You either want the extra power or you don't, anything that you do to add power is shortening the life of something on your truck, if that's a problem stay stock.

Tim, yes I'm aware that electronics do wear out over time, but I don't have any radios or tv's that cost $1500 to replace. My concern is that I don't want to shell out the cash for a new VP and have to do the same thing again in a year or so. So if the Edge Comp is going to kill it I'm gonna get rid of it. It just seems to me more like speculation that the box fried the electronics in the pump rather than fact. Seems like Edge would be buying some injection pumps if their box was killing the pumps and they gave their consumers no warning. No way I'm going to keep running a comp box if it's going to cause my new VP44 to die.

 

[Turbo Tim 1]

This is why I gave you the mileage numbers on my truck, mines been on there for 3 years almost, the comp has been replaced twice but the pump is doing great. Good clean connections and plenty of fuel supply and I think the VP's can go a long time with boxes on them. If my pump died tomorrow and I had to buy a new VP, the only difference would be that I would solder the pump wire connection before the pump even got put on the truck.

 

[Gary - K7GLD]

This is NOT, I repeat, *NOT* particularly a Comp issue, or any other box - they are merely an assortment of individual electronic and other solid state components JUST AS ARE several similar controllers used in our trucks!



Personally, I seriously doubt that addition of a power box really places much additional stress upon other related circuits and components outside what they are SUPPOSEDLY designed to handle in terms of duty cycle or load. Most of what occurs with an aftermarket box is related to altering pulse widths and timing - certainly NOTHING that applies unusual voltages or loads to circuits or components.



Pumps WITHOUT mods fail, just like those do WITH mods... But yeah, *I* sure hate the spectre of being stranded by a 10 cent failed capacitor or resistor... ESPECIALLY when the replacement assembly can run $2000 or more...

 

[ntillm01]

It still is a $1. 98 transitor radio as far as the electronics part. The problem is the fact that it is permanently attached to the $1998. 02 high-pressure, high machine tolerance fuel injection pump that causes the high cost. Component suppliers call this "modular-ization" to simplify maufacturing steps at the assembly plant. More and more electronically controlled mechanical systems are going this way. Certain ABS module electronics failures force you to buy the entire master cylinder/control valve assembly because the electronic module is glued to it.



The way things go I guess...



My 0. 02 on why it failed... it's a craps shoot with any electronic part. Vibration, heat, lightning, humid air and believe it or not, electronic components actually do have a number of cycles before they wear out. Only so many times you can flip electrons back and forth before the resistor breaks down. Remember spark plug wires?

 

[rkressg]

Any body who knows me knows that I do a little with electronic systems and computers



I have my own theory on the failure of the VP-44, and electronics in general, they do not like to change state in any form.



I have never checked the physical output of any box (though I run a tst pm3), but I would be willing to bet that the delta rise in voltage to the pump is beyond the ratings of some cap used in the circuit mapping. You can always use a cap with a higher voltage, just never one too low a voltage rating.



Also, electronics do not like large delta's in environment, such as being under the hood of a vehicle. Electronics also do not like vibrations, such as a diesel engine.



Just about anything can cause an electronic failure. What sucks is when the mfg does not stand behind their product. I would be willing to bet that in the near future, we will begin to see many more VP44 failures because I do not feel it is a durable and dependable unit.



All my work with electronics has taught me one thing, mechanical items, though usually larger and not as efficient, are sometimes more dependent.



-Rich

 

[DToy]

Also, electronics do not like large delta's in environment, such as being under the hood of a vehicle. Electronics also do not like vibrations, such as a diesel engine.



Just about anything can cause an electronic failure. What sucks is when the mfg does not stand behind their product. I would be willing to bet that in the near future, we will begin to see many more VP44 failures because I do not feel it is a durable and dependable unit.

-Rich

Rich, I couldn't agree more. It does suck that the mfr. does not stand behind their product. And the best warranty on a new or rebuilt pump that I have been able to find is 1 year. Don't know about anyone else, but I don't want to be replacing the VP every year or so. Sure would be nice if someone would come up with a more reliable and durable replacement. I'll probably gamble and leave my comp box hooked up, and hope I don't regret it a year from now when the new pump is out of warranty.

 

[GKinney]

I would have to agree with all the posts on this subject... ... the best description I heard was..... "it's a crap shoot" Well that is one true statement when it comes to electronics and every other variable in these things(vp44's). One might last with a race box set on high with only 5psi fuel pressure for 200Kmi. , and then someone else with a stock set up will fry one in 10k mi. Well as a matter of fact... ... my first pump died at 12,000mi... . but that one was covered under warranty... ... and truck was bone stock. I still am kicking myself for not keeping one of my trucks with the P7100. I am more than sure they would last longer than the truck or engine would last if taken proper care of. Oh well..... modern technology,,, can't escape it I guess. I didn't mean to give you the wrong impression on the boxes DToy... . I am sure they are safe... I am just a big chicken to put mine back on yet. I can say that I did love that extra power though with the EZ!! I might just go for some bigger injectors and see what she feels like... . and go from there.

 

[Jeff Knight]

I want to apologize if I got some people worried about there pump or Comp box. I'm sure it was just a coinincidence that my pump failed while running the box. I should have worded my previece post differently. Sorry for any misunderstanding. Jeff

 

[IC Smoke]

What are some of the signs that the VP44 is starting to fail? any strange noises... loss of power... . ?



Ian

 

[DToy]

What are some of the signs that the VP44 is starting to fail? any strange noises... loss of power... . ?



Ian

In my case there was absolutely no warning at all. I still have good fuel pressure from the lift pump, truck was running great. Started the truck up in the morning, let it warm up for a few minutes, left the house and drove a few blocks at 25 mph, took it up to 40 mph and then there was nothing. Coasted to the top of my street and then pushed it down the hill to my house. That's what was so frustrating... even with a fuel pressure gauge and monitoring pressure religiously it just out-of-the-blue died.

 

[WestTN]

I don't have any experience with boxes ( yet! ), but it just doesn't sound reasonable that the size of the injector or injection pressure will have any effect on the durability of the electronics of the pump. On the other hand, a performance box does alter the electronic signals to the pump, so it is very easy to see a cause/effect relationship here. Bigger injectors might cause a problem with the mechanical parts in the pump.

 

[GKinney]

injectors

Ok... . here is how it was explained to me... which makes sense. I was told by two diesel shops... both very respected and well known, the vp44 pumps a lot more fuel than the stock injectors will ever use, even at WOT. Now if you further increase the amount of fuel and or pressure... . it creates a larger amount of back pressure on the pump. With the larger injectors you eliminate some of that extra fuel/back pressure hence taking some of the load off from the pump and its internals. I know you are saying... . why does that affect the electronics..... well we all know that anything that is pressurized rather it is fuel air water what ever is going to create heat. The more the heat... the higher the failure rate of electronics... . injector pumps, computers... tv's etc. So that is what I was told..... is it true??? Well it makes sense... . but I can't say for sure.