so ive been reading around and posted some stuff myself and i keep reading that running too lean will cause an engine to pop. can someone explain this to me? im obviously not very educated in fuel injection, and my guess is that too little gas will just cause the engine to stall out and die, and too much could cause it to pop, but that doesn't seem to be the case. can someone explain it to me?

 

what do you mean pop? backfire?

 

the term ive heard is pop, i think people mean its bad for the engine and makes it blow up/die etc. im just a little confused on why running too lean is so bad

 

What they mean is this.
You Blow your engine.
People usually say pop because it kind of sounds like that when you detonate and it destroys an apex seal.

 

Detonation is a major killer, expecially in turbo motors. the rotary itself is rather detonation resistant with its long combustion chamber and smooth face. However, in turbo motors it is easy to run slightly lean and create a scenerio to precombust, or detonate. When this happens it will try to turn the rotor back against its mode of travel and will usually target the weakest link, the apex seal. Being 2-3mm thick, the seal will not take very much abuse before it breaks. At the least, this will require a rebuild to replace the seal. More often it will become jammed inbetween the rotor and housing, requiring the housing to need replacing. If it is a turbo car and spits out the exhaust, it will damage the turbo's turbine and require it to be replaced. Most people that run into these problems are inexperienced and mod the car to were it runs lean.

 

yeah main.. so dump the fuel.. or get it tuned.

 

Only under heavy load...
Otherwise, the engine will just die out.

Running lean under heavy load will cause detonation.
What is detonation?
http://fc3spro.com/TECH/FAQ/deton.html


-Ted

 

Detoniation is the uncontrolled burning of the A/F mixture.

 

i know what detonation is, and its my understanding that it happens only with turbo's. mines an NA, is there any real danger of running too lean in an NA?

 

i am having this weird thing , is that i press the throttle during idle , or free revving it...

when i let go , my wideband says im lean.....hmmm is this detrimental?

 

you can run too lean in any car. detonation can occur at anytime anywhere, and sometimes it doesnt hurt things, but other times.. well yes. itll shatter a seal.

with an na, theres not much fear of detonation tho .. so don worry yourself none.

 

So in the long run, on an N/A '86 I have no worries with a small popping noise right after the accelerator is released? or should I worry?

 

No, you don't know what detonation is.
Although it's easier to kill a forced induction motor with detonation, you CAN kill an NA motor just as quick.


-Ted

 

It's called fuel-cut decel.
It's used to save gas.
It does not cause any harm.
Read above...under heavy load.
Decel is not "under heavy load".
WOT = heavy load


-Ted

 

That small popping noise is most likely just a backfire, which rotaries do a lot more then your average piston engine. Its just gas in the exause system igniting...chances are if you have a free flowing exaust you are shooting little flames out of your muffler

 

I love shooting little flames out of my mufflers at people who try to tailgate me.....I rev it up and breath fire at them!

They usually back off after that.....not wanting to be set on fire and all

 

alot ofp eople think poping is detonation eh? well usuaully 1 or 2 detonates and your engien is blown.

this "poping" is something ALOT of rotarys do. mine does it all the time non stop. sometimes i can make it not do it. I have yet to figure out exactly what causes this situation but it also doesnt harm the engine at all. I want to say its little bit of gas igniting in the exhaust system (not flames) flames are a bit louder similar to a gun shot. I want to remove me manifold and see if this "poping" goes away. if so then we would obeveously know what the problem is. if its still poping. then we know to look at the fuel consumption.

when your car is idling and you hear all this poping going on, dont worry about it. you can sometimes cure a little bit of ti by adjusting the timing and the TPS. (ive done it). poping will also occure while at light throttle. like i said i dont know the exact reason behind it but just to let you know that its not harming your engine.

if it were detonation.... you would be rebuilding you engine by now

Justin