so i got my injectors cleaned at RC, and it fixed the flooding for a couple days (maybe a week) but now it floods again... not as bad, but it stil floods and the good old fuelpump cutoff switch has come back into play... anyone know what other reasons could cause flooding? i heard that low compression is one factor, is this true?

 

there are many reasons that can cuase flooding...just start up the car pushing the gas at WOT everytime you start it..

 

I think low compression can cause flooding, not totally sure on that though but pretty sure. Not sure what else can cause flooding other then leaky injectors and shutting car off while it is still cold, that is a killer to shut off while cold engine.

 

I thought the WOT trick only worked on series 5's.

 

low compression would make it hardder to start wether u had flooding issues r not


-Shawn

 

damn....i thought the leaky injectors was the main reason, but i guess not....oh well, looks like im going to have to live with it until i get it rebuilt...

 

It also works on the S4 cars as it says to do so in the little driver manual that sits in the glove box if you have one. I read mine one day when I got bored waiting for someone and I came across the flooding thing in there.
The manual was for an 87.

 

need more info--

how about your spark plugs? If they are old or fouled, then you aren't getting the spark you need for full combustion. If they are the same ones you had in before, when it was flooding all the time, you should at least pull them and clean them off good. What about the wires too?

Also-are they stock or not? What mods do you have? When you put the injectors back in, did you use a new set of o-rings? May sound stupid, but some people don't and you NEED to.

 

Low compression is definitely a factor, if not THE factor, in flooding. I have had flooding cars that I rebuilt, which after breakin, ceased flooding. I have, as you did, had cars that flooded and I swapped the injectors with new ones or ones from an engine that did not flood, and it still flooded.

Also something to ponder on, only rotaries flood. But, all imports after roughly 1985 use the same ND injectors our cars do...you dont see them flooding do you?

Thus, you could conclude the problem is specific to rotaries. IT lies in the way they build initial (cranking) compression. Piston engines make almost full compression on the first stroke, but rotaries require several rotations as they get older/weaker to accomplish this. Inject fuel too quickly (before full compression is reached) and you have a flooded engine.

 

It'll say that for most cars, because using WOT is the correct way to unflood any engine. Maximum airflow through the engine is needed to clear out the excess fuel.
However the S5 ECU shuts off the injectors if it sees start and WOT signals at the same time, which obviously makes unflooding easier. With S4's you still need to cut the fuel off somehow, usually with a fuel pump switch or by pulling the EGI fuse.

 

You mention the point about ND injectors often, but that doesn't change the fact that cleaning the injectors quite often fixes or lessens flooding problems (although unfortunately not in this case). Even if compression is low, leaking injectors will make the problem worse, so cleaning them will likely extend the life of the engine.
Either way, cleaning the injectors is much easier and cheaper than a rebuild, and it has many other benefits besides possibly curing flooding, so it should always be considered first.

 

Well, I find it really necessary for some of us to step back and look at the big picture. Basically I have yet to see an actual "leaking" injector. I have seen injectors stuck shut, and even one stuck OPEN.



I certainly wont argue with that. It isnt the fact that Im saying "hey, dont clean your injectors, rebuild your engine", it's just that Im trying to clarify the point to all these forum kiddies who go around repeating what they heard somewhere "hey, your engine flood, clean your injectors and it'll fix it".

 

i installed the fuelpump cutoff switch a while back because it was a major problem for me, so thats no big deal, i can unflood it fairly easy. but since injectors didnt do the trick, what else should i consider before i get a rebuild that might have something to do with the flooding?

i had the injectors done by jeff at rotary power, so im sure he put new o-rings and stuff like that, however im not sure if he changed the plugs, and i dont have any new wires.

 

Just because a lot of engines use the same injectors, doesn't mean that it isn't the injectors. You explained AGAINST your own point when you mentioned the part about pistons vs. rotaries in compression. Since the piston engine makes more compression typically on the first stroke, that makes it easier to withstand a leaking injector and still run. Generally, people in this forum will tell you that the flooding is one of two things--injectors or low compression....doesn't that speak for itself? LOW COMPRESSION, as opposed to a piston engine....of COURSE we are gonna have more of this problem than Supras or Accords.

 

I do not beleive it is a rotary motor issue, I have had many 12A carb cars, and have never haved an issue with this.

If you think it's the injectors, do not just clean them, prove they need cleaning. Put a T in the fuel feed line, and put a fuel pressure test gauge on it. If the injectors are leaking, you will see the pressure drop. When the car is shut off. If it does not drop, then cleaning them will not fix the problem.

I beleive it to be a programming error in the computer. It's like it adds fuel as if it was 30 degrees out, even when the car is fully warmed up, on a 80 degree day.

If one of the stock computer tuners out there can play with cold start/hot start fuel tables, I am sure this could be fixed.

Also it seems to me that when I was researching this, that once people went to a Wolf/Haltech computer the problem went away.

I run the fuel cut switch, or WOT hot start method. But you should not have to do this. I also beleive this is not as much of an issue with the S5 cars (different computer).

 

My car every so often floods even with cleaned primary injectors in it. I have ~90psi all faces. I also have new 720cc secondaries. I have a reason to believe it is the low compression.