Cold Starting Woes

[Newbie]

My car is a real SOB to start when it is cold. Not cold as in has not run in a day, but cold as in it's 50 degrees and it has not been started yet. Once it's warm, it fires right up.

I just read Chris Ludwigs post on carbon apex seals, and it could be that that is what I have in my 13B.

I've tried posting before, and the replies suggested low compression or bad seals. It makes decent power (163 whp) with a stock computer and old exhaust, and I'm hoping it could be carbon apex seals.

In my attempts to solve the issue, I would change to stock plugs for cold starts. I'm sure any factory cold start electronic aids are no longer in place. In reading the shop repair book, it talked about cold start fluid in a reservoir comprised of "90% ethelene glycol and 10% water". How does that work???

I guess my question is how do folks start 13B's with carbon apex seals when they are stone cold? Does started fluid or ether damage anything?

Thanks for the help.

Steve
http://mcscc.org/Gallery/albums/Steve-Smyczek/IM001564.sized.jpg

[lateapex911]

Well, I am not a 2nd gen guy, but you need some kind of answer so maybe this will bump the thread....

The cold start fluid you refer to is actually a stock setup that pumps the mixture in from a little tank when the temp is very cold.....like 0 defgrees F or so.

I think the fluid that was referred to in the apex seal thread was Ether. Rotaries are famous for flooding when cold and under low compression conditions, and the Ether lights up well. Might give it a try, or wait for more knowledgable responses!

[C. Ludwig]

First thing to do is have the engine properly compression tested. Drag it down to a Mazda shop that has the right tool and see what you get. This will give you an idication of what you're dealing with. If the compression is solid you can start looking at other problems like leaky injectors.

[MaxEnergy]

Your problem may be no more complex than leaking injectors. Install a fuel cutoff switch so you can cut the fuel before you turn off the motor. Leaking injectors will allow the residual fuel pressure to put excess fuel into the engine and effectively wipe the rotor housing clean. If your car floods easily this could be the problem. Before you do the fuel cutoff switch you can pull the EGI fuse in the engine bay, crank the engine for 10 secs then put it back in and see if it starts more easily.

Obviously low compression is also a very real cause for a hard starting motor.
jamie

[Newbie]

:happy204:

I may be on to something....This seems too simple but it has worked the past two times.

My friend said it seemed as if the motor was starving for air, so he recommended taking the air cleaner off and manually opening the mass airflow sensor. I'll be darned if it did not work, on two different occasions. I tried starting it the normal way with no luck, and within a second of him opening the cone, it fired right up.

The real test will be tomorrow when I get to a test day and it's supposed to be about 40 degrees in the morning.

I'll keep anybody reading this thread posted.

Steve

[seckerich]

You might check your fuel system. The fuel pump relay is actuated in the stock system by the AFM. Might be as simple as lack of fuel on startup. Opening the AFM allows the system to build pressure.

[Eagle7]

Any chance you've got a leak in your intake system (manifold, snorkel, etc). If any combustion air is not going through the AFM, with your low compression you may not have enough suction to open the flapper door, thus (as Steve mentioned) no fuel.

[Newbie]

40 dergrees and it started right up. At least I can save a starter or two, not to mention being a little more relaxed while setting up when I'm in the first run group.

I'm calling the Mazda stealer to get a compression check, and I may be looking for a rebuilt motor soon.

Steve


$100 later, the front rotor is 7.8 - 7.7 - 7.9 bar at 237 rpm. Rear rotor is 6.8 - 6.3 - 6.6 bar at 231 rpm.

So the rear is a little down on compression and the front is fine. Any guestimates on how far down on power I am with this low comprerssion rear rotor?

Now that I know how to get the car started, I have an entirely new set of things to work on.

Steve