I use Redline SI-1 every 5k miles or so.

It might be overkill and some people tell me that there is no need for that in the FD since the injectors work fine and seldom clog up.

 

I heard that stuff doesnt even work. I just throw in AV gas (101 Octane) every 2 weeks and I heard it keeps everythign running smooth. It does seem to help the car a bit.

 

i'll presume that stuff does work since they have a BMW part number.

It would be my guess that BMW doesn't issue part numbers to companies like Redline if their stuff was junk.

 

I use BG 44K. It's a high end injector cleaner. About $17 for an 11 ounce bottle. Good stuff, but not always easy to find. You can order it on line.

 

I wasnt aware of this. Then your right its probably good stuff. Yet every 5k sounds a bit over doing it. Do you notice a difference after every bottle? Maybe I should get around to doing that to mine.

 

Hey guys, I wouldn't say that using a injection cleaner very 5k miles is overkill. Remember, you are not just cleaning the injectors. You are also minimizing the amount of carbon build up on the rotor faces. You have to remember that carbon build up on our rotarys is not good at all. On high mileage rotarys, too much carbon can freeze the apex seals in their grooves causing you to loose some compression. If anything a good fuel system cleaner should be used on a regular bases just to help prevent these effects. Also I have come to realize that high mileage rotarys that have even low compression #s just need to have the carbon cleaned out. Here is a post on the 20b forum of one of my experiments I did to my 20b engine that had no compression. Start reading half way down the page.

https://www.rx7club.com/showthread.p...5&pagenumber=1

Also, I just recently performed is on my FD with 73k original miles with good results. I decided to do this while I had the engine out while replacing the clutch. Needless to say, I don't have to worry about carbon lock for a long time.

 

It's actually the SI-2 which is a more diluted version of the SI-1 that can be used more often then not.

Well, let's just say that my 230k miles injectors are still original and work fine.

Maybe I should do it every 10k miles.

t-von has a good point.

However, when I use the injector cleaner the car seems to have less HP until it runs through it's tank.

 

There actually is a maching that does the job a lot better. Its made by snap-on. Its a fuel injection cleaning machine, its called motor vac. You run the stock fuel back into the tank, so your bacically looping the fuel system. The machine pumps a mixture of gas and and a solution called "carbon clean". The chemical doesnt burn so it wont burn off when the car is running but dissolves carbon on contact. I tried it with a rotor and the carbon just comes right off. You can put this in you gas tank, its only meant to be injected through the machine. The machine has its own pump and filter, you can set fuel pressure, but max pressure is regulated by the stock fuel pressure regulator. You hook the machine in-line with the engine, with the car turned off. The machine pumps the fuel with the cleaning solution through the fuel rail and its suppose to create a swirling effect which picks up any particles that gets stuck on the top of the little screen on the fuel injector. But on the side feed injector i dont think it would have much effect. You can also spray some of the solution into the intake manifold and it will clean the intake manifold runners. Then you run the car with the fuel injection machine for about 30 mins. When i did this to my fc and fd i gained about 1 inch of vac. We provide this service for $100. There is a vac gauge on the machine and a fuel pressure gauge. So at the same time we check the fuel pressure regulator and and the dead head pressure of the pump. On my fd i had a straight pipe and you can see the solution melting the carbon out of my tail pipe. This **** machine works great. On the rx7 and only cleans the primary injectors since the secondaries doesnt come on at idle. Pm me if anyone in the bay area is interested.

 

A cheap bastard like you spending $17 for 11 oz. of liquid? Thats absurd.

I've never used injector cleaner, and everythings running like it should.

 

Really good stuff is 3m injector cleaner. Used it before and picked up 2 tenths at the track. The kind I am talking about is where you shut the fuel pump off and run it just on the cleaner till it runs out. That was in a car that had close to 35,000 miles on it.

 

I go cheap when I can. That doesn't happen that often with this car. Why does everyone think I am a cheap bastard?

 

Wow thats great! I never thought those machines would work on rotarys because, I always feared that the carbon would break off in little chunks and lock down the engine.

 

Wow thats great! I never thought those machines would work on rotarys because, I always feared that the carbon would break off in little chunks and lock down the engine. Also, I too regained 1" of vacuum after I did mine.

 

I tried a lot of stuff on my old FC and Outlaw FI cleaner used to work pretty well. I could tell the difference. Havn't tried anything which seemed to work on the FD. Cleaning the inj. rail should work pretty well though. I wish I had time to do the leak down test in the shop manual to see if this is what is causing the fuel dilution in my oil.

 

I always use Redline SI-2 and Iv'e never had a problem.

 

I run a bottle of Techron every year - also approved by BMW. Does it work? I don't have a clue but I feel warm and fuzzy when I do it. I've been *told* that you should always run different brands of gas since they all have different additives - kind of a shotgun approach but I have never had a fuel related issue - EVER, in any of my 8 vehicles.

I also wait until a full tank of gas right before an oil change to toss in the Techron since I don't want any strange chemicals in my oil for any length of time.

At 73K and pulling 19 on the vacuum, so I must be doing something right...

 

I use Chevron Techron in all my cars. Every time I put a bottle in the tank, it feels like I've put in a bottle of "liquid schwartz". :-)
Though, I've felt increased heat from the engine bay whenever I put in cleaners. So I don't use cleaners too often -- about twice to three times a year. I don't have a thermostat, so I can't check the engine bay temps. Has anyone else noticed increased temps?

 

I've lost 2 engines with Techron in it.

Not sure if that was the (only) culprit.

inconclusive, but very suspect.

 

injector cleaners don't seem to do much. I've had to replace my injectors because they got clogged. The best way to keep them clean is to keep your gas at above quarter tank. Also, I heard injector cleaners will eat away at your hoses and seals.

 

Got a link?? Name of the machine? I would love to do this to my car right nowl.

 

ive tried it, didnt seem to do anything.
i go by the saying: if it aint broke.. dont fix it

 

I pour in a bottle of techron every time I change the oil on all my vehicles (even my '53). I've never had any problems with it, but it definitly does make engines run a little hotter, until the next tank of gas.

But, let's not forget the best gas additive ever, MMO!!

 

So... here and in the 3rd gen archives, the opinion is:
STP and Chevron Progard are losers,

Redline si-1, BG 44K, Chevron Techron, outlaw FI are winners.

Any benefit from running Chevron gas all the time?

Any new products or test data on injector cleaners?

 

for those who don't know, a higher octane gas burns slower, so it heats up the engine more. the majority of injector/fuel system cleaners are based on some sort of alcohol. high power race engines run some sort of methanol because of it's sickly high octane numbers. the injector cleaner works two fold, it dissolves the carbon while making your engine run a little hotter, which causes whatever carbon doesn't get dissolved by the addative to be burned off. i don't own an FD yet, but i'm looking to buy one within the next year. currently i drive a '92 ranger, and right before i do an oil change i put in 89 octane fuel so it burns a little hotter and add a bottle of STP fuel system cleaner. i normally gain one or two mpg, but i can't feel any difference in power (which, in a stock 92 ranger doesn't really matter, because come on, it's a Ranger). When i buy my first FD, i plan on doing the same process, but instead of running regular fuel (come on, i'm not that slow), it's probably going to be combo of the highest octane fuel i can get my hands on and a bottle of injector cleaner.

 

Will be putting BG 44k In my FD today..
will be reporting back with results, after 1 tank with BG 44k and 2 tanks after.

BTW: DO NOT USE CHEVRON 93 or any CHEVRON..

I don't know why.. maybe their quality control is bad or something.
But everyone in the BMW forums say that Chevron 93 is crap and not to use it.
With the rotory being more PING prone.. I Would stay clear of them also..