Does tapping the wire with a Comp compromise the reliability of the VP44? I need to here from those with some real world data. Assuming the lift pump is in good shape and there is reasonable fuel pressure at all times does tapping the wire have long term draw backs?......Some say yes and some say no........Is there any proof either way?

My plans are a Comp (if I can decide tapping the wire is ok, an EZ if it is not ok) and a modest injector (either a Mach 1.5 or RV275), Scotty fuel kit and a Scotty II.....

I have been considering the Mad ECM but because of emissions testing where I live, I would need 2 ECM's.......I'll stick with a Comp and it's adjustability for now...... Does the Comp help out enough down low to keep you Comp owners happy?........The defueling lag on the bottom end on these 24v's is horrible!.....I don't need a tire burning demon of idle (I still have my 12v truck for that) but reducing this rediculous level of defeuling is at the top of my list!

Does anybody have any info or experience on the Haisley ADD?......I don't know anything about it but does sound interesting......

 

look here http://www.bluechipdiesel.com/inject...pfailures.html

 

The 98.5 and 99 year trucks are the most prone have injection pump problems from tapping the wire. The vp44's have been updated numerous times since it's introduction so the later the model the better the chances of being o.k. with adding a box that taps the pump wire. All Vp44 model years have been known to have injection pump failures from over stressing the pump, such as with a box. Lifes a gamble, it all depends on how big the odds are your willing to take. I have been running mine tapped for the last 30,000 miles with no ill effects. Most of the time no higher than level 3 but I have towed with whats in my signature on level 5 a couple of times, stupid North Dakota winds.

 

I had my VP tapped for 60k/4 years never a problem. I just replaced it because I have a stutter at mid accel. (2200 RPMS) that would not go away. The VP was not the problem.


It is really a crap shoot. I see them die all the time in stock trucks with good LP's.



Justin

 

Thanks for that link - a very informative read...............they did seem to concede that if your pump is on it's way out that a tapped solenoid wire would speed up the failure.........lubrication of the rotor/vane seems to be of upmost importance.......makes a lubricating additive look very important.....

 

You asked for "Real World Data" so here it is on my 98.5 VP
Comp on 5X5 = less than 10 seconds
Does tapping the wire with a Comp compromise the reliability of the VP44?
IMHO 100%, absolutlly, without question on higher mile early pumps.
FYI on mine the rotor siezed with a constant 17psi so......

 

Tapping a wire on a early 24v is a gamble. Although I have not seen a early one fail in 4 years. But thier is a chance is will seize. But if you pump can make it past the first 20 seconds you should be fine.

 

I've been running a comp box for over 100000miles. The only reason my injection pump failed is that I started playing with my fuel tank pick-up unit. I found out the hard way and got dodge to buy me a new injection pump. Its hard on lift pumps, I've killed 4 lift pumps with the box. I'm currently run the fass and I have tons of fuel pressure for the wot blasts. As for more low end grunt, yes, yes. You can do a burn-out until your tires explode with the box. The mad ecm with hard on a stock trannies as you tons of fuel during the first and second gear shifts. I would just use it on a race tranny that has a billet input shaft. I plan to use a mad ecm on my truck with a DTT race tranny, in a couple of months. On level 1, sub 1, you actual have less fuel than stock settings. Nice for emission testing and max fuel mileage. If you have a good injection pump and lift pump, you will have no issues with the comp box. If you have a weak lift pump forget installing the pump. Also run a full time fuel pressure gauge off the schrader valve on the injection pump.

 

You will love the results with the comp but with the early truck you are rolling the dice

 

Hmm......tapping the wire has me somewhat concerned. Maybe I really would be better off with just an EZ.......regardless I will still be doing an injector swap. Does the EZ on it's highest low boost fueling setting still wake up the bottom end enough to make you EZ owners happy?.........Anyone have info on the ADD from Haisley? I think I read somewhere that the EZ on it's highest low boost fueling setting is equivalent to the Comp's sub level 4 setting for low boost fueling, is this true?

 

My drag comp killed my vp44. It lasted about 500 miles put it on 5x5 to blow smoke at my brothers friend and it died. I am now running it with out the wire taped and it has a lot of power. The truck had a ez when I bought it and with the new vp44 and no chip it has more power than when I first got it.

I would spend the extra money and get the comp it has a lot more adjustment and you can always tap the wire for more power.

 

Don't take the easy way out on the connection. Solder a pigtail in and be done with it.

Roman