Thom1

It seems that I read somewhere that periodic use of fuel injection cleaner is required for warranty coverage. Maybe a few times a year??? Redline is Porsche approved. I imagine that it does, but does Techron clean injectors too??? Does anyone know about the warranty requirements?

MikeK

A Fuel injector cleaner is recommended but not required for warranty coverage as far as I am aware for Porsche vehicles. Porsche, as every other auto manufacturer puts out their own injection cleaner. Every manufacturer "recommends" their own fuel additives for obvious reasons. This is produced for them by a third party as Porsche is not in the petroleum refining industry . I work in the petrochemical industry and have been involved in exhaustive tests of just about every additive under the sun. For varnish and carbon build-up (which result from normal fuel combustion) I recommend a SOLVENT based fuel cleaner containing any of the following:

isobuytanol, methanol, Methyl Ethyl Ketone.

read the back of the bottles of the additives you're shopping for. I am biased in the fact of recommending Justice Brothers Injector cleaner as I represent that company. As our product range is not widely available in retail outlets, you may not be able to find it in your area. I will share with you though that Ford manufactures an excellent top engine cleaner called "Carburetor Tune-up" (don't worry about the carb. part on the label, it's an excellent product). This product is not available at every Ford establishment but it is out there. It's a liquid that you add to your fuel system. Do not mistake this for the other ford injector cleaners or their pressurized fuel service. At about $4.00 a can, it performs very well (next to ours of course!). Mitsubishi also has an excellent Fuel injector cleaner that is manufactired for them. Read the labels on the back of Redline, techron, BG, etc. They are detergent based cleaners and we have found they do not perform nearly as well as a solvent based cleaner in our testing. These products are based upon petroleum aromatics, Tolulene, benzene, trimethylchloride, polyetheramine. I recommend you don't bother with stuff you find at Pep Boys as we have not yet tested a product that perfomed very well. One trick that is done is to use a vacuum line to "suck" SMALL amounts of cleaner in to remove carbon build-up on valves. Works great, smells awful! If you're not convinced, burn a small amount of gas in a bowl. when it's done burning, you'll see the carbon and varnish left. Pour ANY of the detergent stuff (techron, redline, etc.) in the bowl and see what it does. Try the same test with any solvent based cleaner I recommended. You can see for yourself the difference in the way each works! Good luck!

Moss928

MikeK

Part No. IC/15P - Plastic Bottle Package?

Thom1

Hi Mike,

Thanks for the analysis. Where can we find Justice Brothers fuel injection cleaner? What is it called?

DP

Ok you got me...I'm interested in "sucking" a small amount thru a vacuum line...BUT how much is a small amount ,and if you suck too much what will happen..(no pun intended)
Also How often should you put it in your tank?? I have heard that solvent based cleaners will hurt the rubber hoses and other rubber parts...Is this true ???

Thanks

Dave

79 Oak green metallic 5 speed

2V4V

Dave,

I would not worry too much about putting a petrochemical solvent in the fuel system. Gasoline in the US contains about 29% aromatics - petrochemical solvents (toluene, etc) used for octane boosting (among other things, as I recall). Gasoline in the land of Porsche contains even 10% more aromatics than the gas we use. And a racer's trick, that has been in use forever, is to mix even more Toluene in the gas to raise the octane.

The same does NOT apply for alcohol - this can wreak havoc on older "rubber" parts not designed for it. However, since gas in many states has contained ethanol for many years now, most of the newer parts are designed to tolerate it. (Technology marches on...)

Greg

MikeK

Greg is somewhat correct. "Automobile manufacturers upgraded fuel system elastomers ay different times. Elastomers in pre-1975 vehicles may be sensitive to oxygenated and high-aromatic gasolines, including alcohols. Elastomers in 1975 10 1980 vehicles were upgraded, but not to the same extent as in later models" (Changes in Gasoline II, Downstream Alternatives, Bremen, 1998). The problem that was found with alcohol based oxygenates was in a problem called phase seperation. When alcohols were used as an oxygenate (i.e. ethanol) they would seperate from the gasoline given extended storage time in gas storage containers. Phase seperation of alcohols (water) can cause corrosion problems in transfer pipelines but is not a big factor in your car. Unless you are storing your vehicle for extended periods.

Here's a test you can try. Get some o-rings and soak them in for example our IC/15 fuel injection cleaner ( Moss). In our testing, we dozens of various o-ring and seals soaking them in straight additive for nearly 15 days. We found no disintegration, degredation, or hardening of any of the rubber. Not true for some origional vacuum line off a mid-70's TR6 I had, Were we found moderate swelling. Try the same test with an additive that contains benzene, yikes! the alcohol complaints you hear are typically carryover's from older mechanics that dealt with the more obsolete rubber compounds. Sort of like my dad telling me to using the engine to assist in braking. You needed to do that when cars were equipped with 8" drum brakes all around. I know I'd rather replace pads than a worn engine from the increased loading.

As far as sucking in the cleaner through a vacuum line. We use an I.V. bottle to regulate a small flow of cleaner into the intake of the vehicle. What you could use is just a small vacuum line from the intake to do the same thing. When i say a small amount, I actuallly mean to suck it in slowly. Liquids, as we are well aware, are not compressable and intake manifolds are designed for gases, not liquids. If you try to draw in too much, you may stall the vehicle. Worse, there is a remote possiblity of hydrostaticly locking a cylinder ($$$). Just be careful and slowly draw in a small amount, you'll be fine.

Oh, by the way, Moss, I would not recommed the Justice Brothers stuff in plastic bottles. Only use the stuff in cans like IC/15. The stuff in the bottles just don't work as well as they are a different formula. They were made for quick lubes and service stations. Just being honest!

Thom, e-mail me your address and I'll send you some.

Moss928

Roger that MikeK!

Thom1

Hi Sharks:

Here are some more observations I posted on the email list:

It seems almost stupid to me that my owner's manual recommends no fuel or oil additives. However, Porsche has changed it's mind before. For example, the timing is different for the 1986.5 right head in the factory manual, and the later training video.

Redline fuel injector cleaner is Porsche approved. The concentrate is cheap. About $7 to treat about 120 gallons - the best I can recall. But, Techron should be effective, too. I believe the advice on the 928 Specialists site. See below:
Fuel Injectors
Dirty, clogged and Damaged Fuel Injections can cause poor performance, engine "miss", erratic idle and hard starting conditions.
Cleaning
For routine Cleaning and Maintenance we(and Porsche) recommend Chevron "Techron" Injector Cleaner which is available at "Wal-Mart"(cheapest), most "Auto-Parts stores" and Chevron gas stations. Follow the directions on the bottle
Recommended Interval : 6 months/7500 miles

Randy V

Costco carries it too - a 2 bottle pack for something like $7.00.

I've used it several times in my 928 - never made much of a difference, however it made significant improvements to my BMW.