Gradual loss of power in 2000 EVC

[xEVC]

I have a 2000 EVC that I've owned for 15+ years. It is my impression that over the last decade or so, there's been a subtle loss of power.

I notice it on a few big hill climbs in the Sierras where I used to do at 60mph without strain, and now 50mph feels more natural.

The van otherwise runs great, passes smog, MPG seems pretty consistent, and has no CEL or codes.

It's possible it's all in my mind

Recently Completed Maintenance
* timing chains
* plugs, wires, and coil pack
* air filter
* transmission filter & fluid

Possible culprits:
* partially clogged catalytic converter
* fuel injectors
* gasoline? I run 91 octane gas, but maybe there is more ethanol now than in the past?

Any ideas?
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2000 Eurovan Camper (Winnebago)
Upgraded with 16" wheels

[SambaBurnsRed]

An engine is an air pump. Moving air = power. There is usually enough fuel available, if not it would start to buck or miss.

Catalytic tech has improved a lot in the past 25 years. So going to new catalytic and if rusty, exhaust system should give you a boost in flow.

I put new catalytics in this Range Rover, and it turned into a beast. Was going to sell but decided to keep it, and turn it into an overland machine. So much fun to drive with that power on tap.

https://www.instagram.com/reel/DFOhZ99ScXf/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==

[paddygarcia]

Converter is a good thing to check. Injectors are another.

I sent the injectors out for cleaning on what I thought was a good-running 2003 with 145k miles, it turns out that one was fully blocked, one fully open, and the rest clogged to varying degrees. Similar results on a good-running Porsche 911 that I refreshed.

They're underneath the intake manifold so unfortunately it's a production to get them out.

[EuroTec]

+1 on the cat suggestion.
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If it ain't broke, don't fix it!

[xEVC]

Great ideas all, thank you.

* injectors can be had for $650 for 6 at europarts-sd.com . I've watched videos on replacing them, and it looks difficult, but something I could manage myself.
* a CARB-compliant catalytic converter is $750 to $1300 at magnaflow.com (? not even sure there are any available for my 2000).

Seems like an expensive way to do "reconnaissance by parts"

I have VCDS - are there any measuring blocks I could watch that would diagnose this?

Also, what about the Mass Air Flow (MAF) sensor : I don't know if mine has ever been replaced.
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2000 Eurovan Camper (Winnebago)
Upgraded with 16" wheels

[paddygarcia]

MAF isn't hard to clean, worth a try I guess?

If you go the injector route, RC Injection will clean and rebuild 6 injectors for well under $200. IMO a good rebuild of original parts is better than new parts these days.

[TheOneTrueQuux]

[SambaBurnsRed]

Regarding injectors, most old, high mileage engines will have passed a lot of fuel, so they will be dirty for sure.

My boat engine injectors were a mess, it was hard starting & smelly (leaks, low fuel pressure, partial spray pattern) but I did have decent top-end power.

[mikemtnbike]

I know it's might be snake oil/placebo effect, but I feel like annual use of Techron (kind of the most reputable FI cleaner product)has helped my van run more smoothly
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1991 Vanagon GL 2.1 AT Westfauxlia. "Frankie" Totaled https://www.thesamba.com/vw/forum/viewtopic.php?t=764510&highlight=carnage
1995 Eurovan Camper "Marzivan"
2020 GTI SE manual

[Abscate]

Check the cats with a back pressure measurement.

Clogged fuel injectors would P0174 code on at least one bank.

It’s not the gas.

Tire pressures up to snuff?
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[xEVC]

Is the catalytic converter back pressure easy to test? I've never heard of doing that.

More info:
* Injectors: could purchase a new set for $650 or get the originals cleaned for $200. I have read a few reports of the OEM injectors plastic electrical connections becoming brittle over time, so this might lean me towards new vs. refurbished.
* I found a much cheaper ($500) California (CARB) Catalytic converter from busDepot here: https://www.busdepot.com/023131089dx

I did some test drives this week running VCDS, and everything looked pretty good:
* Group 025 Oxy Sensor before Cat showed -3.1% (regulation), 4.7% (adaptation partial load) and -2.3% (adaptation idle) - I believe these are all great numbers, being within 5% of zero.
* I did some hard accelerations watching group 045 (Knock Control Cyl 1-4) and Group 046 (Knock Control Cyl 5-6) and all stayed at 0.0 degrees. No audible knocking heard either.

My thinking now - the van is really running pretty good, and I may just run a bottle of Techron through it and drive it this summer, and save the parts cannon for later...
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2000 Eurovan Camper (Winnebago)
Upgraded with 16" wheels

[xEVC]

Forgot to mention this:

On my 2000, with VCDS, Group 009 and 010 show this:

[xEVC]

I decided to replace all 6 injectors. Not exactly on a whim, but based on my gut feeling that since everything else seemed to be working well (timing chains, spark, O2 sensors...) that fuel delivery was suspect.

I'm working on a detailed writeup, but the most amazing find was:

Injector Turd

this chunk of something popped out when I flushed the fuel passages after separating the intake manifold and removing the injectors.
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2000 Eurovan Camper (Winnebago)
Upgraded with 16" wheels

[xEVC]

Recap: after feeling like my 2000 EVC had lost some of its "oomph" over the years, I decided to change out the injectors.

While changing the injectors, I found weird gunk (turds) in the fuel galley.

Afterwards, my driving partner said "This feels like it's driving better" a feeling I agreed with.

Today the data came back: I had sent the old injectors out to RC Injectors for testing and cleaning.

Results:

[SambaBurnsRed]

The injector leaking or dripping is a problem that causes rich condition, at idle.

Being below 200 cc/min max just means you won't reach full throttle peak HP.
The injectors are sized for the max air flow into the engine & some margin for tuning

The O2 sensor takes care of deviance in flow rate, until it can't, then would CEL a lean condition code..

A clean fuel system will feel new and snappy. My boat didn't run so great until I did the injectors, but it runs open loop - no O2 to trim the syatem.

[xEVC]

Having done the injectors and being very happy with the results after several thousand miles, is there any reason to think about doing the Catalytic Converter too?

The only symptom I have that could be cat-related is a somewhat gassy smell right after startup that lasts for a minute or two.

I'm not sure if this is abnormal, or just how the Eurovan runs, combined with the fact that other modern cars are super clean by comparison, it makes the Eurovan feel gassy.

In other words, do the VW catalytic converters "wear out"?
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2000 Eurovan Camper (Winnebago)
Upgraded with 16" wheels

[Abscate]

This might just be high idle caused by sas system. Does the smell go when the car comes back down to 750 rpm, and the jet engine whine stops?

That Magna flow converter will fit but won’t pass smog in CA, and they may not ship it to a CA address
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[SambaBurnsRed]

I got the new catalytic in along with both O2 sensors. Custom exhaust OMG, the low bass note sounds like a small block V8.

Runs like butter, super smooth. It's the quietest, silkiest idling engine we have on the driveway here.

I do not have new injectors tho, so 45 seconds after start-up. when it crosses over to O2 closed loop, it's not perfect until I hit the throttle and get more air (and heat) into the engine. This is likely due to a slightly rich condition (leaky injector or two).

It's supposed to run a bit rich to heat the cat up. The new cat handles that well, and is similar to everything else we have (except very new) in terms of pollutants. A new cat will flow better and be more efficient.