Engine/Transmission (1998.5 - 2002) 280k, should we do injectors and VP44?

[steved]

I got a 99 24-valve with around 280k miles... other than lift pumps, nothing has ever been done to the fuel system (original injectors, original VP44). Obviously, its tired, I'm guessing from a worn VP44.



We are looking to do some PM so they can start traveling, what would you do? I'm thinking injectors and the VP44 would be enough.



Any recommendations on the VP44, I've been out of the 24-valve scene long enough that I'm not sure what's out there now? I would probably stay with stock sticks since they have lasted this long and it is my father's truck.



Cost is a consideration, looking for reliable replacements and not hot rod performance parts. They would be willing to pay more for something with a better reputation.

 

[Houser]

Just a minor upgrade

Hi

You probably do need new injectors with 280 K but if the VP is workin and not throwing any codes just keep er in till she blows. I would upgrade to the Bosch 275 RVs though. I think they are often cheeper than stock and they make a smoother quieter power curve and better mileage.



Houser

 

[blacksheepdiesel]

New sticks will gain you better mileage and higher performance. I would not touch the VP until there are codes and/or symptoms.

Godspeed,
Trent

 

[steved]

Would that cause a degradation in power? His truck is tired to say the least... it runs good, gets 21mpg, but it seems to be lacking power?

We've replaced the manifold, so I know its not cracked. The engine is in fine mechanical shape (no blowby, and no oil used in 5k OCIs)

I was assuming the VP44 would be worn by now? Don't most pumps need rebuild by 300k?? Just trying to get a handle on this as I don't understand it myself...

 

[Mishkaya]

Would that cause a degradation in power? His truck is tired to say the least... it runs good, gets 21mpg, but it seems to be lacking power?



We've replaced the manifold, so I know its not cracked. The engine is in fine mechanical shape (no blowby, and no oil used in 5k OCIs)



I was assuming the VP44 would be worn by now? Don't most pumps need rebuild by 300k?? Just trying to get a handle on this as I don't understand it myself...

Yes, it will cause a lack of power for sure, but at the cost it is reasonable to wait until the time has come to replace the pump before actually doing so. I would say add a timing box to get a bit of get up and go, and hopefully get even better mileage before replacing the pump. Some have been known to go to 400k.

mishkaya

 

[steved]

I'm just concerned about failure with them traveling... if it will ensure less of a chance of failure in the end, it may be worth it.

 

[PRout]

My 2000 truck was a dog (sluggish) when all stock. Some inj's (275's were good, m1. 6's you cant go wrong), muffler delete (keep the resonator), a cheap used EZ set on mild, turbo elbow to allow more boost, decent fuel supply, a valve adjustment, and a correctly operating transmission, it should run great.

My replacement VP was an Industrial Injection stock SO replacement, and it has been flawless. Recommended. .

 

[fox]

What is done for the lift pump issue? Does it have a fuel pressure guage?

If the lift pump is shot, it will still run and thus be down on power.

By that many miles, I bet the stock injectors are about equivalent to 275's!!!!

Put a fuel pressure guage on it and then decide.

 

[steved]

Lift pump is monitored, I know its good.

Valves were adjusted not even 15k miles ago. Its been straight-piped for most of its life. And the airbox has been drilled full of holes, along with the silencer ring removal.

The only things, that I can think of anyway, that have not been replaced are the injectors and the VP44.

The truck runs good, except it doesn't seem to have the power it once did... They are not looking to get more power than stock, just to get back the power they had.

I can hardly drive it, stepping out of my 3rd gen into his tired 2nd gen... but even so, I can tell its lagging power on hills (from what it did new).

 

[blacksheepdiesel]

If that is the case and there are no boost leaks then I would say replace the VP if it will give you peace of mind.

Godspeed,
Trent

 

[jkalchik]

I have a 99 w/ 225k on it.

I had to replace the VP44 a year ago. No real difference before and after (except for the fact that the truck RAN. )

I put a set of Jammer Stage II injector tips in it in May. Holy cats..... made a big difference. My g/f remarked on the black smoke immediately, the old injectors would puff white at start and that's it.

I really don't know what to say about replacing the VP44. The only reason that I could come up with would be peace of mind. The injectors, OTOH, probably should be replaced. I'll be the original injector tips are pretty well eroded, and not giving a good spray pattern.

 

[darkhorse]

I think I've read that the timing mechanism of the VP44 wears & results in low mileage & lack of pep but at 21 mpg it's hard to say.

 

[Mishkaya]

I think I've read that the timing mechanism of the VP44 wears & results in low mileage & lack of pep but at 21 mpg it's hard to say.

Exactly, almost always mileage drops off dramatically before the VP goes. It's a toss up though, if they really do want peace of mind, maybe it would be best to change the pump...

mishkaya

 

[steved]

Can someone direct me to a 24-valve injector replacement thread? I did a quick search and came up empty... I searched "injector replacement" and "injector repair", with no results.

 

[Mishkaya]

Can someone direct me to a 24-valve injector replacement thread? I did a quick search and came up empty... I searched "injector replacement" and "injector repair", with no results.

It's an old one, but the link still works:

http://consortiumlibrary.org/staff/tibor/DD-Injector-Install-Instructions.pdf

mishkaya

 

[fox]

Next thought is to clean the intake air sensor, and possibly the Map sensor.

 

[steved]

I assume you clean these with throttle body cleaner?

 

[blacksheepdiesel]

Brake cleaner. But with the mpg's you are getting I would say they are not dirty.

BTW, is that 21 mpg on the computer or by hand?

If you are going to replace the VP I would not touch the injectors unless you simply wanted higher performance or more mpg's. My 275RV's have 400,000 on them and I still get 21 mpg at 65 mph (hand figured of course).

Godspeed,
Trent

 

[cArNiVaLwOrKeR]

21MPG?



Wow, If I was Guaranteed 21, I would De-Bomb Mine immediately, no questions asked We all know how much money we have Thrown @ trying to get the best and better mileage, I am happy to get 17. 4 all around Mixed driving, I think that is ok.

However, good luck with upgrades and please make sure you update us with #'s . . .



JoeLee

 

[steved]

Brake cleaner. But with the mpg's you are getting I would say they are not dirty.



BTW, is that 21 mpg on the computer or by hand?



If you are going to replace the VP I would not touch the injectors unless you simply wanted higher performance or more mpg's. My 275RV's have 400,000 on them and I still get 21 mpg at 65 mph (hand figured of course).



Godspeed,

Trent

Mileage is hand calculated... he put the majority of those 280k on running 65mph on the interstate.



So I shouldn't change injectors? I'm confused... change one, not the other?