'Throttle Body'

"Dave" wrote

If in fact, you really need the "throttle body cleaning".....it's quite a common maintenance item. There is no design fault....it's just what happens to throttle body units when you operate the engine. They get gummed up with deposits and need to be cleaned occasionally.

In other words...no one is ripping you off. Unless they are upselling you a throttle body clean....when in fact that isn't the problem. But of course, you won't be able to figure that out until you have the "cleaning" done.

Ian

Can you tell us what causes this on some engines and not so much on others? Is it something simple like cheap gasoline, or a heavy right foot?

---Bob Gross---

On direct port injected engines no fuel comes in contact with the throttle body which is actually only a way to regulate air flow into the engine. Normal combustion gasses "back up" onto the engine side of the throttle plates and require periodic cleaning. This back up is more likely to occur in stop and go driving where manifold vacuum is often very low as you take off from a stop sign or traffic light. Engines that see mostly highway speeds have enough vacuum and airflow through the intake system to keep these combustion gasses drawn into the cylinders and not backed up into the throttle body and upper intake manifold. So a city short trip driver will require more frequent cleaning of the throttle body than a car used on the highway. Ain't technology wonderful?

On the earlier type of fuel injection that had the injectors mounted in the actual throttle body and above the throttle plates the spray of the injector washed over the throttle plates and kept them clean.

-- Mike.................................................... "Opportunities are spawned from crisis"

Can you tell us what causes this on some engines and not so much on others? Is it something simple like cheap gasoline, or a heavy right foot?

---Bob Gross---

The biggest contributor to the goo in the TB is the blowby from the engine that passes thru the PCV valve to the TB.

Blowby is caused by too much vaporized oil in the engine crankcase that comes from loose valve guides, too much piston clearance, etc.

You should clean out the TB of this stuff because as it warms up it will emit oil vapors that enter into the air/gas mix and could cause pinging and generally poor performance.

You can buy a TB cleaner but I have doing it another way every year for about ten years on my 91 Eldo. At a 170K I don't use a drop of oil, get 29-30 MPG on trips, and have an engine that simply purrs - very quiet.

My method is a little unorthodox but it gets the TB sqeaky clean. I take about a cup of lacquer thinner and pour it down the TB, then take a can of compressed air and swirl the cleaner around in the TB, then take a MityVac vaccuum pump and remove as much as I can and then do it again until there is no more contaminant in the TB.

Then I pour some more lacquer thinner in while the engine is running for a few seconds. The result will be a TB inside so clean you could eat off of it !

You can also remove the PVC hose and inject some cleaner into it while the engine is running to clean out the PVC and its hose to the TB.

Jack

Throttle body cleaned, 'codes' updated (they were very old, but why were they not updated in the recent service?) cost £70, problem solved.

For now.

Thanks

How does one clean the TB, besides Jack's unorthodox way?

TIA

"Neo" wrote

An old toothbrush and a spray can of throttle body cleaner works well. Just open the plate and spray the cleaner on and go after the crud with the toothbrush.

Ian

???

I think Jack's method is great!

Toothbrush? Wow... that must be a cruddy throttle plate!

I usually run some spray carb cleaner through it while it's running and it works wonderfully.

$0.78 a can at Wal-Mart. How much do the pros charge for this amazingly easy procedure?

"Clem" wrote

That's great.....I didn't make any comment on "Jack's method".....the person that I answered made a comment about that.

Must be.....I take it you've only seen one or two throttle plates in your lifetime?

Probably nothing.....as your method is not really a "procedure" worth selling to the customer.

Ian

Actually, I should rephrase myself.... :o

Agreed. But I wasn't only referring to you. I didn't find Jack's method unorthodox. My 3 question marks intended no offence..

Incorrect. But none that I've fixed with my "non-procedure" required any scrubbing at all.

Probably not. If the customer knew it was just that easy, they'd probably just do it themselves. (As do I) I don't "sell" any procedure to anybody. I have caused quite a few vehicles to run and idle more smoothly by just spraying cleaner through the intake with the engine running.

I have scrubbed throttles before.... but it was during carb rebiulds. I don't suggest that professionals need only to spray a magic cleaner. Just that most vehicle owners can fix it themselves that way.

"Clem" wrote

Probably easier if you just quote off his post....or cut my remarks and info out all together.

Ian

Thanks.

On a related topic, how often do you think that it's important to have the injectors cleaned? Do you think that those cleaning fluids to be poured into the tank for this purpose work well?

TIA

"Neo" wrote

I'm personally skeptical of the "pour into the gas tank" cleaners. I think that if you want to clean the injectors....the more powerful cleaners that are run through the injectors "at the fuel rail" are probably more effective. This involves disabling the fuel pump and simply running the engine on the injector cleaner only.

Ian

i think the pour-in-your-tank cleaners work fine. when my windstar doesn't start first time, i use them and it fixes the problem. maybe i should use them more regularly before the problem develops. that would be wiser. ...thehick

Maybe it's time to replace that Windstar. I use the pour-in-tank cleaners once or twice a year, MAX. Truck starts first time every time. 114,500 miles, though the injector only has about 14,000 miles on it...

Lacquer thinner? Are you refinishing a tube radio? And they say not to use starting fluid or you'll ruin the engine...but Lacquer Thinner?