Sputtering/missfiring after long descents. ?

[william curry]

My question is, just what is the logic, science, of pouring water into an internal combustion engines intake system so as to remove carbon from the combustion chamber?

Why not just save time and pour in fine sand, gravel, and square ball bearings?

Am I missing something here, or is this another urban myth?

[Jim LaGuardia]

In short, us "old timers" use water to create steam, which breaks loose carbon build up.
Of course, it takes common sense and skill to use this method

[lindenengineering]

William
Let me explain a bit further on this "water technique" Or shall I say Wasser Technik!

A liquid cooled engine when driven with a blown head gasket allows some steam/water vapour to enter the cylinder(s) which over the long term will strip out all the carbon residue and render the piston crown/combustion chamber completely clean. If you remove the head of an effected engine the blown cylinder is immediatly apparent.

What was prevalent in yesteryear was the practice of drizzling in water through the inlet tract to emulate a blown gasket by stripping out the carbon inside the combustion chamber. Decoking engines every 40,000 miles was a task that had to be done due to the fact that many engines were built of "monkey metal" some 40 years ago. In short they burned oil and left the engine choked up with carbon. These days I cannot imagine how some of these manufacturers ever got away with it. ___ I even worked for one for 14 years!

Today we use chemicals for this operation, and carbon/gumming of engines can still be a problem. The older LR engines having their roots in Buick stardom can suffer from gumming up causing valve sticking/clash damage. So we pump in metered amounts of combustible chemicals to rid the plenum/combustion chamber of peroleum residue & carbon.
I hope that blows out the confusion on this practice.
Dennis

[Dean]

I wonder if something like Redline's SI-1 fuel system cleaner would help in a situation like this. I just reviewed the tech info on the Redline site (www.redlineoil.com) and they included carburetors as well as fuel injectors. I've used this in fuel injected vehicles and always got good results but I've never tried it on a carbutetor.

[krick3tt]

I have also had a bit of a sputter after a particularly long descent. One street here, going to the valley, is very steep, so third gear with brake is required as there is a stop light at the bottom around a curve. I have taken to giving the hand throttle a couple of pulls to rev the engine and everything is fine then.
Cheers,
Morris...710M

[lindenengineering]

Fuel injection/carburetor cleaner (fuel additives) for the most part work well on either delivery system. Some are better than others.

The modus operandi is of course to follow the instructions on the bottle/package. I suppose like any other "medication" the thought must pass through everyone's mind like:- " well if one bottle is good then two or three will do the job faster and better". In most situations no so. You can do damage to the fuel pump in some instances.

Always remember that fuel is formulated for today's engines with higher volitility for FIE's not carburetor engines so depending upon what brand of fuel you buy and where you can experience some "contre temps" as did our parents who lived with upsets from time to time.

As a foot note we have noticed with SOME repair kits a deterioration in the quality of float level valves with instances of disintegration in service. If you suddenly experience rough running after a competant repair carb' repair it may be time to lift the top cover and check those valves.
The units we have seen that fail have a rolled edge on the lower section with two splits milled 180dg opposite either side to assist in the rolling on production. For those of you not too familiar with the valve it is made up of two principal parts, the body and the base sealing plate. To hold the plate in place the lower edge of the body is rolled. On a Pierborg unit (factory repair part) it is staked in four places and has a duller finish to the brass body.

As an interest factor we have also seen a rise "in tank" fuel pump failures due to owners driving their cars too long on empty to avoid the nasty surprise at the $3.00 plus pump round the next corner.
It would seem the pump overheats inside the welling bucket where it sits and the sudden plurge of cold fuel causes the pump to fail within a mile after fill up. So I suppose if you don't want a $500 bill plus a tow charge for a pump replacement fill when the tank is down to a 1/4 '
Dennis