New Injectors, What do you think

[waynep]

Hello All:

Have a 1997 3/4 ton Subway with orriginal injectors. It has 175,000 thousand miles on it's third injection pump, now with a cooler and so far so good.
Do you think I should replace the injectors? Seems to be running a little rough but not too bad. Am I way past their usefull life?
Also, any brand or model you recommend?
Also, any big issues replacing them?
Thanks for all the help.
Wayne

[greatwhite]

I'd change 'em on spec.

Although there is no GM replacement "schedule" for injectors, accepted recommendation is replacement right around 100,000 is the norm.

Possible failures with old/worn injectors range from poor fuel mileage to cracked/melted pistons.....:eek:

You can get an OEM set for around 500 bucks for all eight, so why not spend a couple bucks on some sound preventative maintenance instead of a possible several thousand on a repair?

:cool:

[sctrailrider]

YEP, I also think they could be ready for retirement, Kennedy Diesel is a vendor here and will be able to fix you up with whatever you need. As stated above, if one does go bad you could burn something up before you really notice it's bad, and with fuel prices what they are and sure to go up, could save a little cash at the same time....

[waynep]

OK, you guys said it well and I know you are right. Can't hurt, ouch $500 buckeroos, but better than a melted piston or wasted diesel fuel money.

I will look around DP vendors.

OK, What brand should I get???? I hear a lot of words about Bosch?

Appreciate all input.

Regards,

Wayne

[Kennedy]

The 6.5 is not really too particular about injector spray quality. It seems to take crappy injectors in stride. I can't remember the last time I heard a 6.5 with a misfire that was not mechanically linked to compression etc.

That said, a good set of injectors is a worthwhile investment. Yours are almost undoubtedly original as they seldom get changed unless the owner sees a reason and as mentioned above they just don't seem to give reason. I think that it would be wise to change them so that you get the most out of your expensive diesel fuel and make your 6.5 run at optimal efficiency.

[trbankii]

I've heard that worn injectors can give you smoke on startup. Obviously, glow plugs will do that as well, but given relatively new glow plugs are the injectors a possible culprit?

[greatwhite]

OK, you guys said it well and I know you are right. Can't hurt, ouch $500 buckeroos, but better than a melted piston or wasted diesel fuel money.

I will look around DP vendors.

OK, What brand should I get???? I hear a lot of words about Bosch?

Appreciate all input.

Regards,

Wayne

500 bucks only sounds expensive at first look.

Check out the price of 8 LB7 injectors and you'll be laughing all the way to the bank (er...I guess that's "laughing all the way to the ATM" now) with 6.5 parts prices.

Sometimes "old tech" is "good tech"......

[More Power]

In general... new injectors are a good idea if:

1- You notice a decline in fuel economy. This is usually a gradual thing over some thousands of miles - sometimes tens of thousands of miles.
2- You notice the engine has gradually begun starting harder with more white smoke, even though the glow system is working fine.
3- Rougher running over time.
4- You have more than 100K, and you are also experiencing one or more of the above.

That said, I've heard from some maintenance-challenged owners who ran the original set to 300K-400K or more who were clueless to the above. Jim

[Robyn]

I too have seen the 6.5 run fairly well with crappy injectors.
The issue as has been mentioned is the waste of fuel $$$ and the possibility of a burnt piston.

One of the most overlooked issues with old worn injectors though is POOR cold start quality.

Once the POP pressure falls off and the spray pattern turns into a Pee Stream instead of a nice fine mist, the startup ability gets pretty hinky, with smoke, long cranking times and rough running for a bit.

Good well balanced injectors (POP pressures very close to one another)
will make cold starts easy and clean.

Mileage can vary even with new injectors. I have seen new pumps and injectors go in and the mileage stay the same or even go down some.

The biggy is the cold start up and overall running.

EGT's can climb quite a bit with old worn injectors, due to injectors that dribble after they should have closed and don't

Also low pop pressure injectors will cause the timing to vary quite a bit from where it should be.

There are many shops that can rebuild your injectors and do so at a very good price.

I use a local that specializes in pumps and squirts and do a set very reasonable.

Good luck

Missy

[waynep]

Hello All:

Found some injectors that claim to be new with Bosch part number for less than 30 bucks each.
Arriving today so I will let you all know how they look and if they are "real" new Bosch injectors.

Seemed pretty cheep vs rebuilts etc but the install kit arrived and it was well put together with high quality parts and return lines not pre cut too short.
Regards,

Wayne

[sctrailrider]

Where did you find them, that does seem a little cheap but who knows ??

[waynep]

I should receive them today and if they are what they are supposed to be I will let you know where I bought them.
I have my fingers crossed also.

Regards,

Wayne

[greatwhite]

"moneyslave" maybe?

;)

If yes, they're military surplus.

I had a set, they even cam e with the NSN on the box.

Worked fine at first. Then popped fine and the pattern was good.

Then my engine cracked a crown.

Tested them again and the pressures were fine, but the pattern was a little off and some would have a little trouble with not chattering properly (pee a bit) and shut off.

But, I cant say whether or not they were the cause of the failure or were damaged during the failure. The engine had 300,000+ on it and I was asking a fair bit from it towing the trailer I had on the back (see sig pic)....

[waynep]

The injectors arrive and look new. Well soaked in diesel fuel.
Only marking is 0 432 217 276
Sharp treads, no obvious use or remanufacture.
Could these be real Bosch?
White no marking on box except:
Injector Part No. 0 432 217 276
Sealed in plastic bags with gasket and top and bottom protectors.

Anyone have any experience with simular injectors?

My experience with mil surplus, if they are, has been really good as the gov tends to have a tough specification for everything that they buy????

Comments????

Wayne

[greatwhite]

The injectors arrive and look new. Well soaked in diesel fuel.
Only marking is 0 432 217 276
Sharp treads, no obvious use or remanufacture.
Could these be real Bosch?
White no marking on box except:
Injector Part No. 0 432 217 276
Sealed in plastic bags with gasket and top and bottom protectors.

Anyone have any experience with simular injectors?

My experience with mil surplus, if they are, has been really good as the gov tends to have a tough specification for everything that they buy????

Comments????

Wayne

The injector bodies themselves will have bosch etched on them and the TD ones will have an orange colored plastic ring on them:

http://www.manufacturer.com/cimages/product/www.alibaba.com/0308/q/10983758_General_Motors_6_5L_Turbo_Diesel_Injector .jpg

OE part numbers:
http://www.hummerknowledgebase.com/fuel/injnos.html