1Z Motor Audi 80 B4: Make the engine more fuel-efficient

Hello everyone,

It is likely that this topic has already been discussed numerous times.
I have also made a sincere effort to search for the answers, but my questions were not fully answered.

Brief introduction:
I will eventually buy a B4 with a 1Z engine because I will soon be commuting approximately 80 km daily and need an affordable and reliable car for long distances.

The vehicle is likely to have around 250,000 kilometers on it (and hasn't been purchased yet).
Consumptions of 5.5 L or less are not too unrealistic.

My thought: Due to the LL, an engine replacement might not be such a bad idea. I'm inclined to use the 205 AFN engine (costing around €10/piece!).
The goal is NOT primarily to achieve higher performance, but rather to save fuel in the TL range.

Does the nozzle change have a positive or negative effect?
Misbehavior should not get much worse.

Or is it better to grab the chip/box and use the serial connectors (or larger ones)?

Again: The goal is fuel efficiency, not maximum power. (optional: 10 CT tuning that can be switched on/off)

Fuel-saving tips such as: low load, good tires with low rolling resistance, high tire pressure, small tires... all well-known... this should not be discussed here.

I would like to hear your experiences & opinions.

Greetings

Jan

Quote:

I would like to hear your experiences and opinions.

My experience and opinion is that it is better to buy a vehicle with fewer kilometers. The 1Z engine has certain weaknesses depending on the year of manufacture (camshaft sprocket, ESP worn out from around 250,000 km), and the timing belt will also likely be worn or nearing the end of its lifespan (replacement interval!).

If, then the car must be very cheap...

Hi,

What does "spottbillig" mean to you? For me, around €700-1000, assuming the interior is reasonably well-maintained and the bodywork is not completely damaged.
KW Wheel replacement, ZR Replacement, and suspension parts are not unexpected.
I am aware that one also needs to put a few hundred euros into the car.

Can you assign the weaknesses to BJ?

ESP worn, means re-seal or completely overhaul?

Can you provide information on the usage and consumption of 205mm nozzles?

If you only want to save money, then set the static. Start of funding (possibly in conjunction with a ZR change) at or slightly above the early limit, exhaust gas recirculation with sheet metal, remove unnecessary loading, ensure sufficient tire pressure.
You can at least compensate for ESP wear by setting the idle volume to approximately 4-5mg/cycle.

Of course, measures like new nozzles are not a bad thing, but how much are you willing to invest, and where do the renovation measures then stop?
My advice: Implement the measures mentioned above and continue until it falls apart....

@ VW mechanic: That's pretty much what I was expecting.

I would be replacing wear and tear parts (suspension bushings, ZR, 205mm fuel injector nozzles, diesel filter, air filter, oil filter, changing fluids, adjusting AGR). Depending on the condition, I would also remove and verschandeln the intake manifold, and replace the brakes if they don't look good anymore. The coupling will also need to be replaced eventually, if not done shortly before.

Can we already achieve 5L/100km with these measures?

Prerequisite: The engine is in good condition.

Please don't buy cheap eBay junk! Then, it's better to remove the old ones and throw them in the ultrasound bath for 3 hours.
Or, alternatively genuine new parts from Bosch, so that you don't have to buy them in GB.

So, I once had a B4 engine with a 1Z motor and it had a mass airflow meter at the time.

I then disposed of it with approximately 370,000 km on the odometer because I would have had to invest too much at the time.

Weaknesses of the car are the front axle, the car is too heavy.
They could have also made the brakes a little bigger. They were really bad. They weren't even ventilated internally. Driving cautiously is not recommended, as the lack of ABS can cause the car to jerk quite a bit.
Power steering is much too light.

At 250,000 km, the gearbox broke.

Consumption was always around 6-7 liters.

I would recommend a smaller car with low mileage and 110 horsepower instead. Or a Golf or Passat, but they rust, unfortunately.

Greetings

There are still two independent weaknesses in the B4. Firstly, the heating heat exchanger is often leaky, which then requires removal of the dashboard. The other weakness is the front axle. The B4 is quite durable thanks to galvanization, but the front axle support is not galvanized and tends to rust.

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Can you already achieve a fuel consumption of less than 5L/100km with these measures?

No. That can only be done with the right foot.
When the holes in the nozzles become larger, the spray pressure decreases there. The flow rate and pressure of the pump remain unchanged. You should therefore expect poorer fuel injection performance.
Since I've been driving my Audi 80 from new, here are a few thoughts.
- The problem areas on the engine have already been mentioned. The KW central screw can be replaced, and when properly tightened, it holds securely. It is likely that the intake manifolds and intake ports in the ZK (presumably referring to a specific engine or component) are quite clogged.
- The B4, like the subsequent models up to around 2004, also used the 012 gear. The weak point of this gearbox is the synchronizer for the 3rd gear. Depending on driving style, it can fail even at 200,000 km. In my case, it was at 430,000 km. Then, fortunately, only a revision of the gearbox is necessary.
- The cable for the rear door will eventually break around 250,000 km and then needs to be replaced.
- At this age, the foam on the back of the headliner, door panels, etc., begins to decompose. The fabric starts to peel away, and you'll have a terrible squeaking sound. All of these parts are no longer available. You can only get a new headliner for the sliding roof version intact (with a lot of luck). You can hardly find a suitable material.
So, if you want to spend about half a year restoring...
Otherwise, the model will last a long time with good care.
I cannot confirm the statements regarding VA, brakes, and steering.

Fuel consumption in sporty country and city driving: 5.5 l/100km.
hg
Herbert

Hello,

all the best tips.
The A4 B5 are significantly more expensive to purchase. Repairs will always come on top.

Why the B4: I've been driving and working on my S2 Coupe (R5 20VT) for years, so I'm very familiar with the problems and technology of this vehicle.

-A hanging ceiling is definitely a problem
-Heat exchangers can always fail.
-Storage VA: PU bushings and rest is
-Axle VA: I've already taken care of everything in S2, not a huge project.

Herbert: Thank you, I wasn't aware of that.
KW Central Screw? Earlier, we were talking about the ZR wheel, or are we just misunderstanding each other?

I like the B4 because of its shape, so the dice *are very likely* already rolled. I am aware that this can sometimes be the case with older vehicles and LLs.

Okay, Herbert, are you advising against using the larger nozzles?

What about chips or power boxes, can I get anything in terms of consumption in the 1Z?
Assuming smooth driving.

The costs and benefits related to engine-related topics should be balanced.
Means: For 500€, I won't buy a box, nor will I install a chip.
In case of doubt, have the nozzles cleaned and start the feed earlier.

Nevertheless, I am grateful for suggestions.

Changing the static start time has no effect on an EDC, unless it is running against a master clock. For this, there is a specialist article.
More efficient fuel consumption requires a better engine efficiency and/or optimized combustion. VW has achieved this with the new models (AFN etc.) to some extent, resulting in more torque and some fuel savings. Ultimately, the investigation led to the PD and CR Motor.
That you think you can achieve this with a "tuning" on the 1Z is, in my opinion, an illusion. Make sure that the compression is good, that the timing is correct, and that the injectors are in good condition. Everything else is merely a questionable attempt to improve performance.
hg
Herbert

Thank you!

Still one more question:

Is there a longer-translated gearbox that fits p&p to the 1Z in the Audi 80 B4?

Interesting is only a long 5. In case the gearbox fails.

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Changing the static start time does not work with an EDC unless it is running against the regulator.

Yes, this is possible within certain limits. If the ESP (Engine Start-up Protection) is set so that it can inject fuel mechanically no later than 2°KW (2kW), then less fuel will be required in the low load and idle range (the EDC would set a later injection start if it could). However, this also has disadvantages regarding noise behavior and is actually quite inefficient.

The fuel injection adjustment on the ESP is mechanically worn, which then prevents the EDC from setting early fuel injection starts. As a result, the engine starts to misfire at high speeds and under heavy load (e.g., on the highway). In principle, the problem is solved with a new fuel pump housing, which means a new pump. 250,000 km is a guideline, but many (!) customer vehicles have already experienced this at lower mileage, usually around 200,000 km. The more you "coast", the less noticeable it becomes. Tempomat 180km/h is often unsuitable for such a vehicle, as it can easily lead to instability and excessive exhaust temperatures (which increases the likelihood of secondary damage).
On my own vehicle, the fuel injection adjustment worked perfectly up until the sale at 280,000 km, but it was probably due to the fact that no "premium" fuel was used and the vehicle was primarily used for long-distance driving.

Chip and Powerbox are completely wrong approaches for such an old and worn-out vehicle.
Leave it as is, fix any maintenance backlog, cruise control at 100 km/h and the car will last a long time.
For other purposes, this part and the changes you proposed represent lost work time and lost money on materials.

Best regards, Rainer

What kind of savings on the amount of alcohol can we expect with a delayed start to dispensing?
Of course, it depends on the driving style, but under optimal conditions: 0.2l per 100KM?

What was the factory-set boost pressure in the STG for the 1Z engine?
It will probably have an overboost function.

Max-Ladedruck and Holding pressure at rated power are interesting.

Hello Jan

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What kind of savings on the cost of alcohol are we talking about with the delayed start date? Of course, it depends on the driving style, but under optimal conditions: 0.2l per 100km?

This can sometimes amount to 0.5 liters / 100 km. This is the case when the fuel injector adjustment is always slightly "over-adjusted" due to wear. You can partially compensate for this with an earlier, static setting. Also, the responsiveness at low speeds also improves, which facilitates early gear changes.

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What was the standard boost pressure setting for the STG (Engine Control Unit) at engine start? It will probably have an overboost function.

ca. 0.9 bar relative, i.e. 1900 mbar absolute.

What do you mean by Overboost? A lightweight waste gate controller does cause some overshooting, but at least you don't have the problems that an worn-out VTG (Valve Timing Gear) adjustment causes.