Engine/Transmission (1998.5 - 2002) Hot Rod VP44 survey!

[BManuel]

A question for all that have the Hot Rod VP44, Please post your experiences with this pump.



I just had a new Hot Rod VP44 installed. The truck has a very annoying idle that shakes the interior, the pump itself sounds like it's coming thru the hood under acceleration, on level ground maintaining speed, it rattles & knocks & shakes & surges to varing degrees dependant on absolutly nothing I can identify.



Help me understand this please.

 

[elandon1201]

I have had mine on for 3 months now I believe. The only problem I have had is the surging idle when extremely cold but I rarely do not plug in the truck. It runs very well, some surging problems with the comp box on and cruise set, but not a big deal. I have noticed a 4MPG drop though, and it is not from a heavy foot my wife has been driving it for about 6 months now and she has the lightest foot I have ever seen. Still a good product, I will find a way to get my fuel mileage up again.

 

[SpicyJam]

You have something else going on there. Mine has been working great, I did have some of those sysptoms you have decribed, but mine was a bad APPS. Mine was the idle, it had a real irratic sound to it. All is good now. BTW where did you get your pump?

 

[rweis]

SpicyJam - When you had the bad APPS, what were the characteristics? Did you try to recalibrate it?



Bob Weis



PM me if you would rather, I don't want to hijack the thread, but am trying to learn more about what happens when the APPS goes bad.

 

[elandon1201]

Industrial Injection pump through floor it diesel

 

[Rman]

I've had a HRVP44 for about 2 months now. It does idle a little funny, from what I've read this can be tuned with different injectors. My Mach 2's stumble slightly but it's not bothersome. I notice when coming off the freeway, especially when hauling loads, it really stumbles bad for a minute or so. It's like the fuel pressure has to stabilize or something. I have noticed a drop in fuel mileage, but it is powerful. Not so much on the bottom end, but when you really give it hell the truck really takes off.



Overall I'm pleased, I just hope it lasts longer than the stock pump. I only squeezed 63k out of that one. And truthfully, I thought I took care of it. I think I'll just thrash this one and see if that makes a difference

 

[jgillott]

I've been running mine for a little over 12K now. It has a "lope" at idle, mostly when hot. The lope clears as soon as the the truck begins to pull.



My fuel mileage has actually improved slightly over the OEM pump. Though, I'm sure that as my original pump was dying, overall MPG was effected.

 

[Froadin]

Just put mine on a few hundred miles ago.

No rough idle or anything else rough so far.

About the only 'odd' thing is it revs up slightly higher when I first start it and it's kinda cold out (below 35 ish). But it's only like 50 to 100 rpm high, and it settles back down as soon as it warms up.

 

[rivercat]

Just to add- are yall sure the lope comes from changing the pump?

My MACH 4s lope at 2500-up rpms out of gear or any time with light throttle like coasting down to a stop, or cruising in the higher gears with barely any pedal.

And are you sure the decreased MPGs don't come from the happy right foot?:-laf

 

[jgillott]

Just to add- are yall sure the lope comes from changing the pump?

In my case, the lope is directly related to the pump. It started the moment the HR VP went on. It is interesting to note that the severity of the lope is directly proportional to the size of injector that I'm running. The larger the injector, the more amplified the lope.

 

[BManuel]

idle

My idle sounds like a Top fuel dragster when it's warm & it is rattling so bad it vibrates the dash board. None of his happened with the stock pump.

 

[SpicyJam]

The pump will idle different if you have stock or slighty above stock injectors. With the injectors I have there is no goofy idle like there is with stockers. So far I am very impressed with the pump. I need to get back on the dyno since I have added even bigger injectors and a larger turbo. Hope that helps, I have sold a couple of these pumps and have only came across that idle once, and it was on my truck, when I put the stock injectors in while my bigger ones were being made.

 

[ARoss]

I think if the pump lopes at idle with stock injectors, that's something that should be disclosed. Having to purchase injectors to clear up the problem doesn't sound quite fair. $1600 for the pump (not to mention the rediculous core charge) and another $700+ for larger injectors ... please!

 

[SpicyJam]

I think if the pump lopes at idle with stock injectors, that's something that should be disclosed. Having to purchase injectors to clear up the problem doesn't sound quite fair. $1600 for the pump (not to mention the rediculous core charge) and another $700+ for larger injectors ... please!

Guess first off you need to really look at what you got when you bought the pump. None of the re-mans have as many new parts in them as this pump, that is the biggest cost right there. Seems unfair to me that you would call a 400. 00 core charge rediculous, you get it back, but if your stock VP is locked up Bosch will not take it, so then who gets soaked for the cash because you may have ran the pump dry or tried whatever. I have seen them with the ears ripped off and keys stripped off of them, why should a vendor have to pay for something that could have been your fault. I would like to ask you if you had done any homework before buying the pump? Did you really need it? Most of that buy it already have larger injectors... ... ... ... . which by the way will help reduce the work load of any VP in our trucks. Not all trucks act the same either, some have the lope, others just have other problems no directed with the VP at all. Some people are amazed when I unhook the VP slip on the VP tester and walla, pump runs as smooth as ever, even when I hit the high idle. So lets see then usally comes to cleaning the MAP, IAT, and some times changing out an APPS, and in some cases the ECM, to get rid of a miss. If the miss is there when I have the jumper on usally leads me to the injectors before I think of the pump. So what is to disclose? Nobody can say for sure how "your" truck will run no matter what you put on it. I just think your statement is a little unfair.

 

[nps]

I think if the pump lopes at idle with stock injectors, that's something that should be disclosed. Having to purchase injectors to clear up the problem doesn't sound quite fair. $1600 for the pump (not to mention the rediculous core charge) and another $700+ for larger injectors ... please!

If you have stock injectors, why are you buying a HRVP anyway? If you are looking for more power but don't want to change injectors, there are ways to get more power for a lot less $. Besides the lope isn't exactly a problem that has to be fixed.

 

[ARoss]

If you have stock injectors, why are you buying a HRVP anyway?

I don't have stock injectors and I'm not in the market for an HR. I was merely commenting on some of the issues I've read. As for the $400 core; that's very reasonable. I know one of the HR builders is charging, if I'm not mistaken, $1800 for the pump and $1000 core ... maybe $800 ... that is what I was talking about.



One of the rebuilders is talking about the HP gains on a stock truck. Then NPS questions why you would want to use it on a stock truck. I added injectors and a Van Aaken, because that's what I wanted. I just needed it for towing. While shopping for ideas, I was told by several owners to purchase an HR, since I needed a new pump anyway, and forget the injectors/VA package. I'm glad I didn't, since I don't thing I'd have been as happy with the result.



I'm not saying the HR pump is not a good thing, combined with the right mods, but I have read several statements that say some people are not too happy with the result ... probably because their trucks are stock or not a kick in the arse off it. Then to find out, to get rid of the lope, they've to buy injectors. All I was saying was some of the information I've read is a little misleading and, therefore, should be clarified. Sorry, didn't mean to ruffle anyone's feathers.



I think I'm responsible for taking this thread off track and, for that, I apologize!

 

[tractorface]

I have an old HRVP44 from Piers. Smooth as silk. A little smokey, slighttttly high idle, and nice power improvement.

 

[SpicyJam]

I have an old HRVP44 from Piers. Smooth as silk. A little smokey, slighttttly high idle, and nice power improvement.

Like I said each one will be a little different. Industrial Injection supplied Piers with those also. Each truck acts a little different no matter if it is injectors, a VP, or a fueling box, work on these engines enough and you will see all kinds of differences. Sometimes when I drive a customers truck I think that I wish mine was this smooth, or why is this one rougher than mine?

 

[rivercat]

Would lower C/R make a diffrence? like my rig being a HO if I installed a thicker HG and lowered the C/R to be like a SO or a little lower would that make it smoother.

Im just like everyone else on here I want to run my truck for a long time and sooner or later the stock VP is gona quit. Im just planning ahead to see wht its gong to be like when that day comes.

 

[Jetpilot]

Would lower C/R make a diffrence? like my rig being a HO if I installed a thicker HG and lowered the C/R to be like a SO or a little lower would that make it smoother.

You will need a lot more than a thicker HG to lower the compression down to the ETC level.....





Doug