JumpyRoo

Just this: It harms a car to run out of gas. Isn't this, in effect, what the proper use of the antiflood switch does? How does this affect your engine?

JumpyRoo

Also this:

If running out of gas and cutting the fuel aren't the same thing, someone please explain the distinction.

rico05

It is just like switching the car off. It is like when you let off of the clutch in gear. No real harm done if you turn off the key as soon as the engine dies. I have a fuel cut switch, and I have seen no problems.

JumpyRoo

Good to hear! So I'll install one

seveninphilly

iTrader: (7)

My question as well

will the engine still get oil ?

I try to turn the key off just as I hear the engine spudder or is this bad ?

Felix Wankel

Running out of gas is bad for the fuel pump, not the engine. Its different than cutting the fuel flow off.

Felix Wankel

The oil pump is mechanical, driven by a chain that runs off the eccentric shaft.

You're doing fine the way you're doing it now.

JumpyRoo

This antiflood switch just sounds more and more fantastic

Samps

If you car had a nasty habit of catching on fire every day, and you figured out a way to rig up a fire exstinguisher to put it out when it happened; would that be a good solution? YEAH I KNOW! It does seem to fix the sometimes difficult problem but it is really just covering up a problem. The car should not flood, PERIOD. So if it does something is wrong. A switch seems to work fine for alot of people, but I personaly would rather fix the underlying problem.

JumpyRoo

What's the underlying problem? Or cause?

No7Yet

Either leaky injectors, low compression, or some combination of the two.

The first can often be remedied by removal and cleaning of the injectors by a professional.

The second, well...

Brandon

JumpyRoo

I thought the computer causes the injectors to leak?

SureShot

According to the 89-91 FSM: WOT while cranking will cut fuel and unflood. If I have to move the car and shut it off cold, the next time I crank it, I start with WOT and listen for the fast even spinning sound of a flooded engine. If it's normal, lift the throttle and she starts, if it's flooded, hold the throttle for a while, then lift.

Icemark

Only when the engine doesn't get a chance to warm after starting.

Its on the rich/fast warm cycle from starting and if you turn it off before its warmed, when you go to re-start it will want to re-start the same fast idle rich cycle.

Flooded like that is easy to fix, just hold the accellerator down all the way while cranking.

If it is flooding while the engine is warm and cold then it is the injectors jammed open or leaking.

rico05

Dosen't the switch just cut power to the fuel pump? Mine on my 91 is wired into the black wire w/ a white stripe connected tot he yellow connector under the dash.

Salguod

Sorry Samps, on some cars you can totally fix this problem, but the 86-88 T2 models have a CPU bug which, in a nut shell, provides the engine too much fuel when the engine is hot. A new engine, injectors, plugs, wires, ignitiors, solenoids etc, will not fix the problem. The only fixes for this for some of us is an aftermarket delay circuit for the fuel pump, or a fuel pump switch.

You are correct that if there is something wrong (like leaky injectors), you should fix it, but for many of us including myself, a fuel cut switch or delay circuit is the fix. I spent around $1200 in parts trying to fix this problem on my 88 T2. When I finally broke down and built a fuel pump delay circuit (which delays the fuel pump being turned on while trying to start the car for about a second), my problem was solved.

I wish I had that $1200 back.

later,
Salguod

Salguod

1) Some 86-88 models DO have a CPU problem that DOES cause the engine to flood when the car is warm or hot. My 88 T2 is one of them. The fix is a delay circuit for the fuel pump solenoid off the CPU, or the use of a fuel cut switch. Having an aftermaket fuel pump which runs higher than stock rail pressures makes the situation even worse (floods more often).

2) Holding down the accelerator to unflood the engine ONLY works on 88.5 through 91 models. Doing this to the 86 through early 88 models will only make it WORSE. For the early 2nd gens you have to pull the "EGI COMP" fuse, then hold the pedal to the floor and crank it for a few 10-15 seconds. Then you replace the fuse, and start it normally (assuming that there is not something else wrong with your engine).

Trust me on this I have a ton of personal experience with this problem. I did a ton of research online, with Mazda, and with some of the best RX7 mechanics in South Florida. The above statements are the honest FACTS.

Later,
Salguod

88 Turbo II
Melbourne, FL

JumpyRoo

How much does flooding harm the engine in the long run?

jimmyv13

Can you remove the negative battery cable and pump the brakes to reset the ECU so it won't start-up in the rich/warm cycle?

Icemark

From personally owning an 87 (6/86 production date) bought new and owned for 10 years and 135k miles; my 88 GTU (3/88 production date) sitting in my dad's garage with 55k miles; and my 88 vert (8/87 production date) with its 120k miles, I can without a doubt say that you are incorrect on the years and that information.

Any FC cold flooded by the computer (and not mechanical issues) can be fixed by holding down the accelerator pedal while cranking. Besides my personal experience in this, this same information is found in every single FC owner’s manual from 5/85 through 8/92. Doesn't anyone ever read their owners manuals?

I wonder how many people have hooked up the infamous "Fuel Cut switch" or "anti-flood switch" without even trying that. And while the computer may have an emissions related issue/bug; 90% of the time someone floods an RX-7 is because they have something wrong with the car or themselves are doing something wrong (like pumping the accelerator once while starting).

I wonder and doubt if any of the more experienced and respected rotary mechanics like ReTed or others that frequent the board have any sort of "anti-flood switch" on their car(s).

To answer JumpyRoo's question, the biggest issue is shortened cat life and weakened oil viscosity, both of which will lead to shortened engine life if not corrected.

To answer jimmyv13, no that will not correct the problem.

Salguod

That may be for non-Turbos, I don't know. If you had taken a second to read the post above my last one you would have seen that I was talking about my experience with early T2s AND I was talking about HOT start flooding problems, NOT COLD.

I know you totally believe that you are Mr RX7 Know it all and all, and in a lot of areas you may be, but not here.

My T2 ABSOLUTELY POSITIVELY WOULD NOT START BY SIMPLY FLOORING IT. I tried that over and over again. It NEVER worked. I spent a fortune trying to find something other than a stupid fuel cut to solve my problem, because I didn't believe it either,

There are hundreds of people that post on this site and a bunch of other RX7 sites, as well as several people I know with 87s and 88s that flooring it didn't work either. Flooring it seems to work on 89-91s to get them started hot or cold, but not the 87-88 T2s.

The ONLY things that finally solved the problem for me and hundreds of ther early TII oners has been a fuel cut switch, a delay circuit, or just plain pulling the fuse.

drake696

if ur car runns out of gas it will take some of the scrap from the bottom of ur tak in it as well thats the harm

Icemark

Simple question.

Did it do that new? Or did the flooding issue appear after a while?

If it started having the problem after, say 30k miles; then that again points to an mechanical issue in the car. If it had the issue from the first day it rolled off the dealers lot (as I doubt) then it could really be a computer bug.

If you are the 6th owner and don't know if it did it new (as I suspect) I would first fix the mechanical issues with the car before installing any sort of aftermarket switch or delay or other band aid.

JumpyRoo

Well, I will tell you that the flooring works on *my* FC, but it seems to really stress the car. Like, it takes it upwards to twenty, thirty seconds to make it work after some hard work on the engine's part, especially the starter's part--and if I'm right, the fuel pump will help things quite a bit. I can always start the car when it cranks, but yeah. It takes some art with the accelerator. You know, perhaps the fuel switch can cut time down by sixty percent on how long it takes to start the car...

NZConvertible

Regarding the Series 5 "cranking fuel cut", remember all the ECU does is stops opening the injectors. If your injectors are leaking, and have been dribbling fuel under residual pressure, the engine is flooded before you put the key in the door! So injector health should always be the #1 thing to check.