Can Fuel Addidtives Affect Q Idle & Computer Reading?

[hobber]

Would adding a few addiditve/Injector Cleaner negatively affect a Q's idle and computer readings?

[PalmerWMD]

Generally no.

The only (rare) exception would be, if the cleaner knocked off enough dirt to plug/obstruct an injector.Which is why it is important to clean injectors at reasonable intervals, so you never have that situation, but always only clean off a small amount of dirt at once because they never got super dirty in the first place.

Fred...

[hobber]

Thanks Fred. How about affecting the computer's reading of the fuel?

[PalmerWMD]

Thanks Fred. How about affecting the computer's reading of the fuel?

Unless an unsually large amount of cleaner was used, the answer is also no.For it to affect the the chracteristics of the fuel as a whole one would have had to put in a multiple of the recommended quantity.Even using 2 or 3 times as much as recommended, would not affect these things.

Fred...

[PalmerWMD]

The only time this might become an issue is, if say instead of 1 large bottle meant for a full tank, you use on 2 on one thats almost empty.

Fred...

[greg_atlanta]

The only time this might become an issue is, if say instead of 1 large bottle meant for a full tank, you use on 2 on one thats almost empty.

Fred...

I think it's quite fun to put one small bottle of Techron in 5 gallons of gas.

:ylsuper

But wouldn't do that with REAL injector cleaner like BG 44K.

[Q45tech]

We do it all the time 11 oz [of 44k] in 5 gallons telling the customer to fill up soon. Having used over 55 cans in mine even it is pretty benign. 11/[128x22.5]=0.00382 or 3/10th of a percent is not much of anything. Now 10% is something to worry about....like the 10% of ethanol or MTBE.

[hobber]

All of the gas in Phoenix, where I live, has 10-15% of MTBE. Other than moving, is there anything we can do doing to lessen the impact the fuel in this area has on our cars? Is it possible there is better gas in the area?

[hobber]

PS. The original idle problem I mentioned in this thread occurs only during the cold start. Once it warms up, it smooths out.

[PalmerWMD]

Gas formulations are usually distributed by region.

It may be possible that you live right on the border of two regions (I am on a state line between 2 states with different regs).

But I belive that Arizona gets all its fuel from the same refinineries (CA).

But I may be wrong, I suggest you check with locals at your dealer or at a local car club.

Someone will know <if> non MTBE gas is available somewhere in your area.

Fred...

[PalmerWMD]

PS. The original idle problem I mentioned in this thread occurs only during the cold start. Once it warms up, it smooths out.

I my personal experience this has often a sign of injectors out of spec.

Fred...

[Q45tech]

MTBE is not the MAJOR killer it seems to be the aromatic content or some interaction between the components - the refinery blend and water causing the corrosion which raises the resistance.

Generally allowing water in or not changing the fuel filter every year are the culprits.

I use iso dry gas [99%isopropyl alcohol] [every 4 tanks 1,500 miles and BG 44k every oil change] [costs about $50 per year] many of the mas discount products contain methanol which will destroy the injector [careful]!

These injectors work hard and 2,000 hours is the design life [100,000 miles] not to say they won't last 250,000 miles.

In Arizona the damage may already be done.

Again $1500 every 100,000 miles is just part of living there with a V8 [kind of an extra gasoline tax of 1.5 cents/mile or 26 cents per gallon].

To my knowledge no one has found a solution other than changing them when they fail.

[hobber]

I hust had all of my injectors replaced, and I am still getting the rough and loss of power at during cold start. The tech says the injectors are within specs. The check engine light does not come on, so no codes or messages to the computer.

Go figure?

[PalmerWMD]

Hobber,

Have you had a good TB cleaning done?

Fred...

[hobber]

No, will that make a difference with the cold start? I thought the TB cleaning was preventative maintenance?

[PalmerWMD]

Dirty TB cause poor idle as well as losing power for you.

Actually poor cold start is a bit pointing towards injectors, if they were ohmed and declared ok..Hmm, were they ohmed both hot and cold?I had once 8 brand new injectors installed and one was bad causing poor idle.

Replaced thru warranty.

There are not so many causes left other than the ones mentioned..Hope you find it soon.

Fred...

[hobber]

Thanks Fred. I have a question regarding the injectors. According to the tech, the injectors ohmed out correctly, but I don't know if they were checked both hot and cold.

Is it possible or likely that an injector could ohm correctly, but not work properly during just the cold start? Wouldn't they perform badly all the time.

[Professor_Mike]

Are the replacement injectors OEM? There are a lot of items to cause a rough idle on cold start. Can you check power balance while cold? Does it seem like a miss from one cylinder? Cleaning the throttle and intake would be an excellent step. If you look in the throttle bore with the butterfly open do you see a lot of carbon buildup?

[hobber]

The injectors are not OEM. Is it possible or likely that an injector could ohm correctly, but not work properly during just the cold start? Wouldn't they perform badly all the time.

What exactly is a power balance check?

When I initially start the car in the morning, the car idles smoothly at 1000 rpms. Then within 5-7 seconds as it attempts to go to normal idle of 650 rpms, that is when idle neddle bounces between 800-400 rpms. Within about a minute or so, the idle smooths out to normal.

During this warm up period, if I attempt to press the accelerator before it is completly warmed up, it acts as if it is not getting any gas at all. It just sputters.

Yes, there is some residue buildup.

[landtodd]

In a power balance test, the Consult stops the spark to one cylinder at a time and measures the rpm drop. If all cylinders are contributing as they should, the drop should be close to the same when each cylinder is cut out. This is how you decide which cylinder is missing (if that's the problem).