about 2 weeks ago i started premixing my gas 16oz per fill up and i only fill when its close to empty. well about 1 week ago my engine started to act funny. rough idle, starts then dies only when cold 3 or 4 times befor i can even back out of my driveway. when i rev my engine up it revs fine but on its was down to idle it makes a "burrrrrrrrrp" sound. and it has power all teh way through the power band still. the engine has 128xxx miles on it and only a few upgrades to the car. i dont know what it is, any ideas or comments are appreciated. thanks!

 

it shouldn't be killing your engine... maybe it's a mechanical failure due to wear and tear? Did you remove your factory oil injection system? U could always use a compression test.

 

sounds like you have a vacuum leak, check your rubber intake hose for cracks where it clamps to the turbo or throttle body depending on your application.

if you have even moderately worn spark plugs they could be on the verge of fouling out also, change them if you can't find a vacuum/air leak.

 

I dont see it killing your engine....check your fuel injectors and fuel filter. Premixing will slightly shorten the life span of those things so maybe its time to get them cleaned and/or replace them.

 

Actually, it will increase the longevity of injector function, and have no effect on the lifespan of your fuel filter.

 

Are you running that in ADDIDTION to the stock oil metering system? If so thats waaaaay too much.

I ran 16 oz per fillup with my MOP system totally removed.

 

ditto^



misconceptions run rampant around here...

 

And the search button strikes again...I'd like to see proof though

 

i've seen a lot of people blame problems on premixing but never see any proof, i don't have the tools, time or materials to do the extensive research but i will reiterate what i said in a different post. 2 stroke dirt bikes do not have chronic problems clogging filters or injectors(yes some newer dirt bikes have injectors) or jets due to 2 stroke mixed gasoline. i don't think rotaries are the exception to this, people have been premixing in rotary engines since their inception, including when they switched to FI.

 

Cutting fuel filters apart at equal intervals of 16,000 and 23,000 miles, give or take 1000 miles, a car running a premix ratio of 120:1 and a car running zero premix showed no visible difference in filter element.
Furthermore, pressure drop across the fulters, measured with a pair of fuel pressure gauges, was conclusively equal in both tests.
Wideband testing using an FJO system is yet to show any difference in fuel delivery due to a clogged fuel filter on an engine running for nearly two years, premixing 128:1, for over 30,000 miles on the same OEM filter.
Fuel injector spray patterns were tested on one each of the primary injectors of the 23,000 mile engines with no differences whatsoever. Both sets of fuel injectors were cleaned and balanced, by me, when the engines were first installed.

As for the injectors failing... perhaps you can explain to me how adding a lubricant to the pintle of the injector, which reduces the operating temperature from frictional losses and helps to prevent the pintle from sticking, somehow makes the injectors more prone to failing?

Even better, can you explain WHY an fuel filter would clog from premix?


The search button is fantastic for finding posts. Its not always all the great for finding fact. I have done personal testing of identical engines running with and without premix, and found no differences to longevity of injectors, their spray pattern, or to the longevity of the fuel filter.
Until you have done testing yourself and can prove otherwise, retract your statement.

 

Sean, I agree with everything you state...

It's just very strange that not only me but a couple of other forum guys have said that when we first started premixing, somehow the pump inlet sock gets all gummed up. Not with premix, mind you, just...crud. Varnish, maybe, I don't know...

Yet when the filter is changed, no more problems ever crop up again...Strange...

 

I love scathcart...

 

TCW3 premix was made for fuel injected engines and is safe for catalytic converters. end of story. read the label.

 

i just changed my fuel filter fiter before rotary revolution so i dont think it would be cloged up all ready. could this be caused by to MUCH primix? i thought i was using a good amount but could it be overly lubricated and causing it to sputter and die when its cold? allong with the rought idle? i will be checking the vac lines after school today just to check.
P.S. i still have my OMP on the engine but it is leeking and the control arm on the pump is disconnected. it is so messed up it is not injecting oil anyway but do you think maybe this it the problem?

 

If your compter is running fine for years and you install a new game and suddenly you get bluescreens... doesnt mean the game caused it but it does mean you had a pre-existing problem before and it just took maxing the computer out to show the defect.

Changing the way you perform maintenance on the car wont effect it so quickly, BUT it is possible you are now showing signs of a pre-existing condition the car had BEFORE you started using premix.

What you describe can be caused by so many things, vacuum leaks, ignition problems, failing fuel injectors...

It just happen to start at the same time.... dont blame the premix just diagnose it the right way.

Try starting by diagnosing the BAC system and checking for vacuum leaks.

Also bear in mind that at this age and milage, if it's the original engine it's near the end of it's lifespan.

 

Now could this "tale of crud and failing filters" also be due to which 2 stroke used. I know there is good stuff and cheap stuff out there. Maybe it was cheap oil w/ some impurities. Or maybe a bottle that sat open for too long with some debris in it. Who knows. I'm not saying I think this is the problem, but just curious. I mean we're talking arond an ounce per gallon max. I don't know about ya'll, but that pretty diluted.

 

Nah, I've been using the Wal-mart stuff for years, and you can't get much cheaper than that, lol...

It was just that one time, like a week after I pulled the OMP and started premixing, that bastard filter clogged. It was original and had like 150K miles on it at that point, but still...

I was on a quest to find the best premix ratios for a while, and discovered some interesting tidbits:

Down at about an 85:1 ratio and lower, gas mileage actually improves markedly. This is great, except for the fact that the "extra" blowby adds prodigious amounts to the oil system...Which means there's a little too much premix for a daily driver...

At about 120:1 and above (including the 128:1 that most guys use, the ounce per gal thing), gas mileage starts to suffer a bit. Which means lubrication levels are not quite where they need to be (at least, that's my theory).

My happy ratio now is 100:1 to 105:1

 

TCW3 , MADE FOR FUEL INJECTED ENGINES IT SAYS RIGHT ON THE LABEL

whats so hard to understand about that

 

OK......... Geez. My only "question," not arguement (or opinion, or view, standpoint, whatever) is that aren't there different grades of oil? High qual. and low qual? Just like even though 87 octane gasoline is for cumbustion engines, arent there different quality gasolines depending on who you get it from? I know my car runs better when I fill it up at mobil, and less good at kwik fill. Just a thought.

Thanks fo goin bezerko for a damn question. It's nice to see you've got some self restraint when talking about the "all-mighty" premix that adds Madd HP, yo. (thanx Ddub).

 

TCW3 is a minimum quality stamp, if its not TCW3 its crap.

 

my take on it is that the premix oil may have some mild petroleum detergens that may free up deposits in your fuel system, leading to it clogging things up...but pretty unlikely

 

i use the $6 a gallon oil that Wayne uses, there isn't many cheaper out there and i push upwards of 15psi of boost at times and i have had 0 problems.

 

If I understand this clearly; in an effort to have a better running engine, you started running premix . . . IN AN ENGINE WITH A 150,000 MILE FUEL FILTER . . . .

It's conceivable that a car with a more complete regular maintenance schedule would outlast one with premix and 150,000 mile filters. YMMV

 

why not? premixing will save an engine if the OMP fails, a plugged fuel filter will just leave you stranded on the side of the road. and also who sais when you buy a car it doesn't already have 150k on it?

 

When was the last time you drained your gas tank and cleaned it out... betcha its all clogged from loose crap in the tank, before pre-mix would have done anything.