Injection Pump Questions

[Zephyr]

Sorry about the extensive vehicle history to explain my question. My area of Colorado requires lug-down opacity testing of the exhaust prior to vehicle licensing. My vehicle is driven approximately 5000 miles yearly and has passed emissions with 20 to 25% opacity over the last few years. 35% is the cutoff. This year, the vehicle failed with 60%. Nothing else has changed internally with my engine over these years. I allowed the shop that did the dynamometer testing to proceed with additional repairs. They replaced all the injectors with supposedly pop tested rebuilds. The fuel filter and air filter were replaced and a retest was performed which yielded a 61% opacity. At this time, I was going to proceed with a waiver of the emissions testing that is allowed because of total dollar repairs spent. Out of curiosity, I turned the fuel pump down two flats and had an emissions retest performed. The result opacity was a passing11%, but expectedly, power was down significantly. I was able to go ahead and license vehicle with these results.

My question is:
Does a worn injection pump produce more or less fuel flow into the injectors? Am I correct in assuming that this flow would generally be at a lower pressure? Thirdly, if the smoke cleared up significantly following fuel adjustment, does this give me any idea as to the status of the pump internally?
FYI, the pump has approximately 30,000 miles on it since a quality rebuild was performed.

Thanks for any replies!

 

[Nero]

Can't answer your question about flow, but typically a pump will last closer to 100k miles. My engine has the factory pump on it, 93k miles running no issues still.

 

[IDIBRONCO]

They replaced all the injectors with supposedly pop tested rebuilds.

That may be a problem right there.

Does a worn injection pump produce more or less fuel flow into the injectors?

I'm not qualified to answer this one.

Am I correct in assuming that this flow would generally be at a lower pressure?

Yes.

Thirdly, if the smoke cleared up significantly following fuel adjustment, does this give me any idea as to the status of the pump internally?

Maybe, if it was a higher mileage pump. With 30,000 miles, I'd say not really. The entire problem here probably wasn't overfueling. The exact setup passed in previous years and nothing was touched. Without going into the quality, or lack thereof, of the injectors, I would be EXTREMELY upset at any shop that just threw injectors in. The FIRST thing that they should gave done is to check the timing. That was probably the entire problem in the first place. As fuel parts (pumps and injectors) wear, the timing tends to retard. Retarded timing will also tend to smoke more (as will timing that's too far advanced). Since nothing was touched from previous years, I'm leaning toward retarded timing from wear and possibly improper timing after the IP was initially installed. My recommendation would be to find another shop to work on your truck. At least find one that will check things over before just throwing in parts and handing you a large bill.
One more thing, ideally, you should replace the pump and injectors at the same time since they wear out at the same rate. Forget what you may see in You Tube videos and other online places of questionable information (social media). I understand that cost is a factor here, so you still want to replace them as closely to each other as you can. That's with the timing being set after each install.

 

[Zephyr]

Thanks for the replies. Unfortunately with my limited knowledge, I know more than 95% of the local shops about these engines. Few of them have ANY clue. The previous pump and injectors were supplied by a reputable supplier on this forum. I timed the pump at install personally 9.2BTDC. I should have retimed it before allowing the shop to ding me $3K. I was just pushed for time and wanted the truck to pass emissions. Live and learn, unfortunately. Tonight I turned the pump back up 2 flats, power is back and I suspect so is smoke (it was dark for the test run). I will recheck the timing before going any further.

 

[IDIBRONCO]

power is back and I suspect so is smoke

Probably so, but you have a piece of paper that says that you passed the emissions check so you're still good for another year.

 

[Black dawg]

What takes place during this lug down test?

 

[onetonjohn]

I thought California was the worst when it comes to smog. One for California - we get a pass on pre 97 diesels. No testing required (for now).

 

[Rdnck84_03]

@Black dawg I am not absolutely sure about this but I am guessing they use something similar to a chassis dyno to put a load on the engine. Basically doing an emissions test in a simulated towing situation.

So they are doing the testing under the conditions where most all N/A diesels produce smoke.

James

 

[Clb]

This opacity testing is a way to say smog without saying smog.
1
Changing injectors was wrong.
Should have timed it.
2
the "30 k reman " pump is probably the culprit albeit adjusted for Propper timing or failed intermals.
3
you need an injection man not a all brands service and testing shop doing repairs .

My kneejerk reaction is that you shouldn't have to pay them to worsten the problem.
I'd ask the owner for a refund or perhaps mention calling the bar for help....
WAY before applying for a waiver because it often comes back to bite ya...

Good luck.

 

[Clb]

I thought California was the worst when it comes to smog. One for California - we get a pass on pre 97 diesels. No testing required (for now).

For all the CaliHaters
NeinerNeinerNeiner

 

[Nero]

Just Cali doing Cali things

 

[Zephyr]

What takes place during this lug down test?

I haven't been able to get a tech to actually explain it, but my understanding is this. They run at 40mph, 50mph and 60mph and then brake the dyno until rpm's fall, measuring smoke at that point. It is meant to stimulate pulling under load. I believe all those numbers are performed in top gear which is idiocity in the first place since I would be down shifting. It fails the 40mph lug only, duh. I also wonder how much technician variability there is in this test as the shop that had done my emission testing for years closed up and I ended at a new location. Regardless, the truck passed (with reduced fueling), and is good for another year.

In response to OnetonJohn and CLB, you can celebrate! This state is becoming the new Commierado. Soon we will surpass you in many others areas of freedom infringement! Perhaps when all those wacko Californians move here, I will be able to sell my place in the mountains for a bundle and join you on the beach with my banned diesel and well-equipped gun safe. With the demand of relocators, property values are chasing yours. My property tax evaluation went up 175% for next year and I became a new overnight millionaire!!!!

 

[Clb]

Gawd
I
Hope
So

But yea been seeing this for a while now.

 

[IDIBRONCO]

I thought California was the worst when it comes to smog. One for California - we get a pass on pre 97 diesels. No testing required (for now).

Just a few years back (3 or 4 I think) Colorado passed a law where they don't want to see any smoke from a diesel's exhaust. I can understand it for rolling coal, but for driving an old diesel?

 

[Cant Write]

@Zephyr come join us on the western slope!!! I welcome you with open arms!!

I think us sparsely populated counties are still avoiding carb and emissions testing thus far. But who knows when they’ll implement it.

You are right, we are becoming ******-rado. If I sold my house, I’d be a HOMELESS millionaire. Could not afford this state anymore. Treading water as is. My taxes raised nearly that too....and for what? I see no good from it.

Fly-over country (Great Plains region) looks greener everyday.