Car cranks but won’t start, smell gas after cranking. Any ideas?
 

Car didn’t have a main relay, got that and installed it. I’m now getting spark and fuel. Engine cranks but won’t start, I smell gas after cranking it. Any ideas?

Easiest way to get it to start if you're having that much trouble is remove the lower spark plugs (leading) and use a medicine child syringe and insert like 3-5ml of oil (regular Dino oil) into each housing and fire her up and prepare for smoke out the butt end.

BUT first I would pull the main egi fuse in the engine bay (if you're an S4 or push the gas pedal to the floor if you're an s5) while cranking to clear the Chambers before attempting the oil procedure.

Works every time for me if my car has been sitting for months. In fact I just did it last month.

If it truly is low compression or flooded this will work. If you have lost an Apex seal etc then this will not work and you need a wizard.

To me, that's kind of like putting someone on a blood thinner because they're a little overweight. You don't know for sure that they need it, right?

The purpose of putting oil, or ATF into the combustion chamber is to build compression. But, we don't know that he's flooding due to low compression. As I stated, what if his battery is weak and he's cranking it? That can flood a rotary. He should have a fully charged battery and complete a deflood procedure, only AFTER he confirms it's actually flooding in the first place by pulling the plugs.

To the OP, if you are indeed flooding, the plugs should be soaking wet with fuel. Perform the deflood procedure and see if it starts up. If it still doesn't start, get a compression test done. If you discover you've got low compression, then you obviously have an issue with the engine. In my experience, putting oil or ATF into the chamber is not really the first thing you should do. If you have carbon build up and let's say an apex seal is stuck, the ATF may be able to break down that carbon and free it up. But, as Pnoy pointed out, you will have a TREMENDOUS amount of smoke pouring out of the exhaust for anywhere from 5 to 20 minutes, depending on how much you put in there. Typically, you only need a couple tablespoons.

Inspect the problem and diagnose. Don't jump to conclusions and don't dump ATF into your engine before knowing the problem you're trying to solve.

Nick

If you're able to do this safely this is a good way to try to build compression on an old engine. Pour MMO into the combustion chambers and then tow the car around in the off position but in 2nd or 3rd gear, turn the car "on" see if it starts to catch up or runs.

Before you do this perform a compression test.

What's MMO Ian?

We had an RX-8 in the shop which had sat for a few months while the owner was out of town. We did a compression test and got nothing on one or more faces, can't remember. We poured ATF in and let it soak for a day or so and then began trying to start her using a brand new starter and a battery jump pack to make sure the RPM's stayed high enough to unstick the apex seal and it worked. Our thought was the centrifugal force of the spinning rotor may be enough to sort of fling the apex seal out and free it up. This would allow the apex seal into the rotor housing to re-establish compression and make a seal. It sounds like you're doing the same thing with this method, but just far more aggressive and probably far easier, since the engine would be turning much faster using your method. Our approach took us a few days to get it going again. Cool idea dude.

Or, maybe I'm missing something...?

Nick

Marvel Mystery Oil, it's not as harsh on seals as ATF and about the same price.

Both methods are using the same thought process, break down the carbon and free up seal movement!

I figured that was your angle. Very neat idea, never heard of it and will share with my local rotards.

Nick

Im just saying it takes 5 minutes to do my procedure and viola if it works yay if not well then keep looking for a problem..... but i think 8 times out of 10 its flooded. Low compression on old engines really does a number on the old gals. Every time my car sat for extended periods (months) it would not re-start and only until i built compression up did it work every time after until of course it sat again

Edit: from the sounds of OP's problem im assuming it sat for awhile since he seems to be putting it together "it didnt have a main relay" so im also assuming it has low compression from sitting so dumping fuel into a low compression engine would spell flooding/no start and it would help possibly if this is the issue.

Pulled the EGI fuse and cranked it, still smelt gas. Was not able to hold the throttle to the floor due to the throttle pedal not being hooked up.

Update
 

Got the car to start! But it dies out when I take my foot off the gas pedal. Found a few more Vacuum leaks... could they cause it?

Bump
 

Also, engine sounds super healthy after de flooding it

Yes.
-Ted

I would loosen the idle screw ( counter clock wise which pulls the screw up) quite a bit so it idles high and maybe it won't die on you? Then after it runs for a few minutes maybe turn it back down to a good idle. It won't hurt to idle a little high. Also google how to check for vacuum leaks. If you have a vacuum leak it is harder to start, but after it is started for a minute it will cause high idle due to pulling more air from other areas.

Where is the Idle screw located?
 

Forgot to mention