fact or fiction

[rgrowan]

Ok, I just read that i am playing russian roulette because I haven't replaced or rebuilt my injectors yet and I've hit the 100k mile mark. Is this true? Also does anyone have any experience with the "wellington automotive parts" "new" FSD/PMD ? They claim it is better than the stanadyne. Is it? The "bucking" that I experience while driving at a constant speed is getting worse. Happens at all speeds, but at highway speeds, it is downright scary. FSD, injection pump(still original) or injectors (still original)? or any combination thereof... I have a '99 suburban with a recently installed "optimized 6500 block and heads. I have a remote FSD from Heath diesel. Just replaced the lift pump and am getting great fuel at the filter. No air in fuel. As always, I am turning to the experts...Help.

[More Power]

Ok, I just read that i am playing russian roulette because I haven't replaced or rebuilt my injectors yet and I've hit the 100k mile mark. Is this true? Also does anyone have any experience with the "wellington automotive parts" "new" FSD/PMD ? They claim it is better than the stanadyne. Is it? The "bucking" that I experience while driving at a constant speed is getting worse. Happens at all speeds, but at highway speeds, it is downright scary. FSD, injection pump(still original) or injectors (still original)? or any combination thereof... I have a '99 suburban with a recently installed "optimized 6500 block and heads. I have a remote FSD from Heath diesel. Just replaced the lift pump and am getting great fuel at the filter. No air in fuel. As always, I am turning to the experts...Help.

The best recommendation for knowing when to change the fuel injectors involves analyzing the engine's startability, fuel economy and general engine smoothness.

Over time, the engine's startability, fuel economy and general engine smoothness slowly decline due to fuel injector wear. Injectors can last anywhere from 100,000 to 500,000 miles. It all depends on how the vehicle starts and runs. Fuel injection shops recommend replacing the injectors at about 75,000 miles. They sell injectors. Again, I base the decision on when to replace the injectors on the engine's startability, fuel economy and general engine smoothness.

There is no time-bomb or Russian Roulette related to keeping the injectors in-place for the long-term that I'm aware of.

Stanadyne recently released a new and redesigned PMD/FSD that they call "Bullet-Proof". Where the original PMD module was black in color, the new one is gray. I hope Stanadyne's new module solves the problem.

DTech released their aftermarket PMD module about 3 years ago. It is so good that GM has been recommending its servicing dealers use the DTech when working on an electronic 6.5. At the present time, I recommend the DTech. You really need a known good PMD/FSD module to use for troubleshooting a DS engine running problem, and to carry with you while traveling.

Jim

[trbankii]

I suppose that, as Jim states, with the engine smoothness decreasing from less than optimal injectors you could stand some greater chance of cracking the block due to surges and harmonics? Sort of similar to the forces from a worn out harmonic balancer? Maybe that is where the Russian roulette comes in?

[Burning Oil]

The WAP is a relabled Dtech. I do like/sell the Dtech, so far I have not had any come back. Its to early to tell on the new Standyne. I have all the gold pins needed to set up a new style Stanadyne cable now. Let me know If I can help.

[Hubert]

I think another good indicator of injector health is the diesel puff on launch or opacity test. Tired injectors tend to give a bigger puff or more soot with sudden off idle fuelrate increase.

[rgrowan]

I get that! Maybe I better think about an injector update...

[Robyn]

The acid test for injectors is a good cold start at or below 40F
A good sound engine with stock glow plugs (all working) should start right up with a nice cackle.
The stack should show a tiny puff of smoke just after it lites off.

If you are getting bluish gray smoke after startup and or some missfires for a few moments the issue is likely the injectors (If the glow plugs are all working)

The only good test of the injectors is to have them POP tested to see if they make muster or not.

Most will start to lose their edge after 100K
I have put 200K+ on injectors in 6.5's and they get cranky to start and will smoke at idle and other nasty things.

Keep us posted

Missy

[rgrowan]

My truck sat for 4 months while I was waiting for a new block (long story) so I'm wondering if that might have an effect on injectors and injector pump...

[Hubert]

I get that! Maybe I better think about an injector update... Taken as you get the diesel puff on launch.

I think you'll always get this to some extent with older trucks more so and with age this increases. I am not saying new injectors will clear it all up just suggesting once over 100K miles and the puff gets bigger and injectors will help reduce it. If your state does an opacity test then injectors and IP have an appreciable influence on the score assuming intake air is good.

If your truck has sat for a while run a few tanks of good fuel through it with good addititive then re-evaluate. Heavy dose of Stanadyne and Cetane boost plus 8 for 2-3 tanks is my suggestion.