vaughnc

This has not been stated very well before, but here's something everyone should know.

You can majorly flood your engine so bad, the gas left over in the engine will it will eat the built up oil film that acts as a natural sealant. The oil sealant helps make compression in the engine, and you will have NO COMPRESSION. You won't feel any air pulses coming out of the sparkplug holes, and a little or no gas will come out of the holes.

This happens when you don't warm up the car fully before turning it off (idle @ 750 rpms). Basically the extremely rich mixture of gas/air injected into the engine during startup doesn't burn off and causes this.

It will flood so bad, you'll think the starter isn't engaging because all you hear is a wirring noise during starting. That's actually your engine turning, but you won't hear the normal catchug, catchug, catchug at all. No amount of fuel cut will help either (no EFI fuse or gas pedal fuel cut will help).

2-4 tablespoons of ATF in the spark plug holes per rotor, new sparkplugs, and 45-120 sec of cranking will re-establish the oil film, cause good spark, and make compression on the engine.

This can happen even if you have excellent compression & clean / non-leaking injectors. It apparently worsens in the wintertime for some reason.

So warm up those cars when you move them or just go for a quick drive.

vaughnc

Note the "sitting for 5-15 minuets and not cranking" issue is leaking fuel injectors. You are getting comrpession but the air/fuel ratio in the engine is WAY to ritch and you need fuel cut/more air.

Samps

I bet a few have trashed an engine when it was just extremely flooded; if this is the case.

Rotor13B

I tried telling people this before, all i get is no, the motors blown

ScrapFC

iTrader: (5)

I've heard of this. Haven't seen it, though. The ATF makes sense. Itseems to me that if you flood it so bad that it loses compression, you'll want to change your now heavily contaminated oil.

j9fd3s

iTrader: (3)

it is more likely to be a misrouted vacuum line or a vacuum leak

mike

vaughnc

hmm good point ScrapFC. Going to change the oil asap (yes I flooded my 89 vert NA engine).

j9fd3s, that might be the problem on some.. but probably not the issue on my TII. It only has problems firing up in the 8-30 minuet window. After that I don't need to engauge the built in fuel cut (us Series V owners are too lazy with the "fuel cut at your feet" fix).

Probably need to pull the injectors & inspect them.

j9fd3s

iTrader: (3)

had the same problem with my t2, after i fixed ALL the vacuum leaks it wanted to start hot or cold.

mike

Rotorific

iTrader: (1)

You know this had happened to me recently when i changed my clutch out. All i did was clean my plugs and disable my fuel pump. It went from no compression to starting up in less than a minute. (S4 GTU)

David88vert

Wish you had asked me earlier. This happens to me about once a month ....

I know better, but I'm not sitting out in the cold till the car warms up ......

puaka

iTrader: (5)

Then start it and go back inside. Or, install a remote start :]. By the way, how is flooding your engine going to contaminate your oil????? Unless something is wrong, nothing from the combustion chamber will make its way back into the crank case. When this happens on my '87, I just put a cap full or two of ATF into the intake while turning the car over (ignition disabled of course). After a few minutes of pulling the EFI fuse and cranking it, she'll fire right up.

Later,
Mike

Rotorific

iTrader: (1)

David i dont care if you live in the uppermost part of GA its not cold in GA....hehe

Puaka - did you realize that there is oil in the rotorhousings and that is the oil sealant that Vaughnc is talking about
-Gabe

Psychoblue23

wow thx for the tip I ahve been moving my car in the morning to let someone out of the garage. Been starting it moving it then shutting it off. Damn looks like i have to run it a while now.

- James

StarionX

If you need to do that all the time, you might think about getting a Turbo Timer. This way, when you have moved the car, set the timer for say 10 minutes, then you don't have to worry about it getting flooded.

Just an idea.

vaughnc

A bit misleading - there's probably a bit of ATF in the oil now.... and since ATF is VERY detergenty that's probably not good for the oil system.

racermike

Actually the oil to be concerned about is in the rotor itself, not the housing. If you are concerned about the ATF contamination, use motor oil. That is what is being injected or metered anyway, which is used to lubricate the apex seals. I doubt that the little bit of ATF that could sneak past the side seals will hurt anything. It is MORE likely that the extra gas could get by, but again not in very large amounts. If it happens frequently then the contamination could obviously be greater. Also, after I re-establish good compression, I remove and clean the plugs, before re-establishing fire.

J-Rat

iTrader: (2)

WRONG!!

You are talking about an engine that relies on a small film of oil to make compression. Once that film is eaten away by excessive gas, gasoline is free to head straight for the oiling system. And it will, TRUST ME.

There is always a SLIGHT leakage in any internal combustion engine, otherwise no crankcase gasses would ever devolop. Without Crankcase Ventilation, the motor would eventually develop pressure and start blowing these gasses by the rings or seals, depending on if you drive a recip or a rotary.

NEXT!!!!

Rat

NA_VersionFC3S

sorry for the stupid question, but what is ATF?

J-Rat

iTrader: (2)

Automatic Transmission Fluid.

Rat

dr0x

I just want to let everyone know ATF will **** up your cat. Plus its really messy once you get it fired up. Not to mention cranking the car for upto 120s is really bad for it.

IMO, and I just did this (Ill explain) w/ my blown motor. Unfortunately, 3 seals are blown on the rear rotor not the fact its just flooded.

Get someone with a truck or SUV (or even a buick- they are as big as a truck lol) to either push start you, or tow start you. Just get it going @ like 4000rpm in first gear with the key turned to on. I had my fuel switch off and the accel floored for about 2 blocks. Then I let off the accel, re-enabled fuel and it fired right up. Even w/ my motor being flooded and running off 1 rotor it still fired. I really suggest doing this over ATF. Its easy as hell, free to do, and its better for the car. My car was so flooded if you pulled the spark plugs there was literally fuel DRIPPING off them. This took less than a minute of towing to bring back my blown motor.

BonsaiRX7

so whats the point of this article? let your car warm up before you go out and drive?

Im just trying to gather all the information I need for perfect care of my car when I get a 7 hopefully someitme around march.

Rotorific

iTrader: (1)

The point of this article is to not start and turn off your car with in a matter of minutes.
It floods your car.... in some instances it can flood to the point that VAUGHNC has described.
It just happened to me like a month ago.
The point of this article is to show and warn newbies and people that are just beginning with RX-7s that sometimes a motor that is hard to start and has no compression doesnt neccesarily mean a bad or dead motor.
GET IT GOT IT GOOD GO GET YOUR ROTOR'N ON

racermike

"ATF will **** up your cat"

Don't know if thats true, but it seems possible. Another reason to use motor oil!

"4000rpm in first gear"

It would be better NOT to spin it so fast, use 2nd gear.
The towing idea works because the faster you spin the motor the less "leak down" you will have, thus more compression. If you have no tools, it will work.

I have rescued cars from the street or elsewhere and WITH tools here is what I do:

1. Disable fuel and fire.
2. Remove plugs and spin motor until the fuel cloud subsides. Purging raw excess gas from chambers.
3.Add oil. Spark plug holes or intake, carb..
4.Spin motor until good "whoosh" out plug holes or 20 seconds. If no "whoosh", add more oil and spin for 20 more seconds.
5.Install plugs and spin motor for 20 seconds.
6.Remove plugs and spin motor for 20 seconds. Purging excess oil.
7.Clean plugs and re-install.
8.Re-enable fuel and fire and start.

If it still does not start, repeat.

Although this thread is about F.I. cars, Carbed cars have been known to flood as well. Also, a car that has been sitting a long time may have the same problem.

vaughnc

exactly - always warm up you car till it idles @ 750 rpms and the temp guage shows warm. Even if your just moving it 100 feet or running to the store & back but the car didn't warm up all the way.

I went through the troubleshooting process thinking my injectors were leaking big time, I dropped an apex seal, or (originally) my starter wasn't egaging.

Nope, compression #s are over 100psi and injectors are spraying fine & retaining the fuel line pressure when the car is off. Starter works fine.

Never realized a flooded engine would drop to 0 PSI of compression. That's after the gas sits in the engine for 4+ hours after you flood it that you're oil film gets disovled.

racermike

"sometimes a motor that is hard to start and has no compression doesnt neccesarily mean a bad or dead motor"

And if you don't believe it,,,,call me. I like to buy the cars with these "blown motors"!