Injectors? Kennedy CPU Question?

[scot5146]

Hey everyone-:D

I have read all the threads on the Marine VS stock injectors but am still a little foggy on the issue; and to make it more complex I also have a CPU upgrade to throw into the mix... Its all going into my 1999 K2500 6.5 diesel suburban.

I got a Kennedy Performance CPU from a buddy for a great price and I want to put it in to my suburban but will I gain anything with the Marine VS Stock injector or am I just gaining performance and efficency from how the CPU works?

This is going to happen in a few weekends with some buddy's from my fire station that are going to help me work on my truck, none of us a mechanics but most are pretty good around and engine... We are planning to do my;
-CPU
-Injectors
-Crossover Pipe
-Glow plugs/ Controler
-Fuel Lift Pump
-And if we have time (UNIVERSAL AIR-AIR INTER-COOLER KIT), i may have to get to this later depending on time...

I have everything but the injectors...

I have already done the 4" exhaust, amsoil relocation oil filtration kit, fuel filter (I do every oil change), cold air intake, various suspension stuff and brakes etc...

QUESTIONS?

What will I gain with the CPU and Injectors (Marine or Stock)... Can these in combo:confused: damage the existing injection pump?

Are there any things I need to be aware of before messing with the Injectors, this is my first time changing them on any diesel?

Also can I just plug in the CPU or is there a detailed process, I dont want to mess up any existing stuff in the programing?

Thanks for any info...

Mike

Firefighter/ Vancouver WA

[DmaxMaverick]

Keep it simple. If you have a Kennedy program, contact him and he will advise what you have, and what works best to achieve your goal (power, economy, both). Personally, I don't advise "marine" or "Hi Pop" injectors for almost all on-highway vehicles. The power gains aren't significant compared with the inconvenience of the lesser streetability. Good injectors, of any "type", won't damage the pump. Higher pop pressure does cause a higher pump load, but is not significant in most cases. Poorly calibrated injectors can cause premature pump failure, or may not work with a pump at/near half it's "normal" lifespan. High quality stock injectors will always perform better overall than any poorly built "performance" injector. If you do get marine injectors, have them tested before install for a pop range inside 1%.

[scot5146]

Thats good to know, I am going to stick with stock injectors and have a set rebuilt at the shop that Missy always recommends in Portland, I will make sure to have them bench test prior to install...:D

[Robyn]

The pop pressures with the DS4 nned to be within specs for the IP to have a good long life.

I had the ones set on the DaHoooley engine to 2000 PSI. This is slightly under the top of the specs. I did this because the IP was not new.

The other thing was to have all the injectors set to the same pressure as close as was possible.

This will asure the closest cyl to cyl timing. My feelings about this relate to internal stresses placed on the crank shaft by cylinder timing thats all over the map.

With a spread on the pressures, the timing of each cylinder can be different, causing harmonics to set up. Injectors that are not matched will cause a rougher running engine that is most noticeable at idle.

The Marine injectors are used to their best advantage with the DB4 high output marine injection pumps.

The stock injectors will handle all the fuel that a DS4 can squirt.

The big selling feature of the marine injectors is pretty vague.

Mostly the buyer will see such an improvement over the OLD CRAP that was in the engine that they think they got something.

A fresh set of good stock squirts will make the same power.

I bought a set of "Marine" performance injectors once from an Online outfit.

Took them over to the shop in Portland and we tested them out.

ABSOLUTE JUNK. The POP's were all over the map and the spray pattern was about like an old cow peeing on a flat rock.

Mark and his crew over at DFIS in PDX do good work.

As Maverick mentioned, give JK a call and have him tell you the ins and outs of his programming.

Missy

[scot5146]

Sounds good, thanks everyone... I will get the stock squirts and give JK a call this week to figure out the CPU...

Thanks For All The Help!

Mike:D

Firefighter/Vancouver WA

[More Power]

I talked to a local 6.5 owner the other day. He asked about the "40 horse injectors" he read about online, and whether they would produce an additional 40 horses...

I gave him the same advice I do everyone else. I asked him if he was running a stock injection pump. He said yes. I said a stock calibrated set of injectors would make the most sense.

Plus, I told him to call the vendor and ask if they have dyno data showing a performance gain when comparing their performance injectors with a new set of stock injectors. Then, mention that you're planning to run your truck on a chassis dyno to confirm the performance gain.

So far as I know, no vendor has published dyno data for their injectors - comparing new stock injectors to new 40-horse injectors. I'm sure that comparing old worn out stock injectors to new performance injectors would produce a difference.... Gotta compare new to new...

[scot5146]

Hey real quick I thought of another question, one of the donuts at the crossover pipe is shot and is making a pretty good exhaust leak... Will this effect my MPG and turbo performance? Or is it to minimal to notice...

Thanks

Mike

Firefighter/Vancouver WA

[DennisG01]

Computers are coded for each individual truck based on VIN, right? I mean, you can't just stick a computer from someone else's truck into yours since the security system won't allow it to start?

I have JK's injectors. I can't comment on how much of a difference they made since I changed those at the same time the engine was being rebuilt. But, I can say that I don't have any drivability problems. At the time I was doing it, I figured it couldn't hurt.

Depending on how bad the donut is leaking, yes, it could hurt MPG - possibly throw a 236 code for low boost. Nothing major to worry about, though.

When you get around to fixing the exhaust, try passing a golf ball through the crossover - the stock crossovers are double walled and when they are bent, sometimes the inner wall collapses too much.

Do you still have the stock downpipe?

[scot5146]

I replaced the down pipe with the 3" when i did the 4" exhaust kit, works great and been very happy with it...

I was on the same line of thinking with the crossover pipe, I figured since I had to fix the leak I might as well replace the pipe... It has not throw any codes yet but I am sure I am loosing a little power and MPG's... I went from 18-20 mpgs a few months ago to around 16-17 as of yesterday...

I am having the squirts built and I left a message with JK about the CPU stuff so hopefully get a response soon...

Thanks

Mike

Firefighter/Vancouver WA

[rustyk]

Personally, I don't advise "marine" or "Hi Pop" injectors for almost all on-highway vehicles. The power gains aren't significant compared with the inconvenience of the lesser streetability.

I have hi-pop injectors on the Peninsular Engines built AMG (with the suitable IP). My engine is shoving around a motorhome in the 16K lb. range, so it's obviously not comparable to a pickemup. The AMG is 230 HP vs. 190 for the OEM - and the difference is notable.

Anyway, the engine is quite tractable in all RPM and torque ranges. Fuel economy with the stock engine was ~9.15 mpg. Now, it's 12.5+. How much of that is from the injector/IP combo, I don't know. But it didn't hurt.

[Kennedy]

The term "marine" is used liberally to make injectors worth little to nothing sound like something.

I don't use the term and actually hate it.

We build our high flow/high pop injectors locally using genuine Bosch parts and they WORK. Thtis is what I recommend.