themadninja

Hey all! I've been having this trouble with my RX7 as long as I've owned it (about 8 months). Basically what's happening is that it won't start on the first crank when cold. The most efficient means I've found for starting involves cranking for 1 second, stopping, then repeating about 6 or 7 times until it finally catches. Here's video:
<iframe width="420" height="315" src="//www.youtube.com/embed/vb_QIZGiA0E" frameborder="0" allowfullscreen></iframe>
The sound is pretty quiet, but you can see the tach when I'm trying to get it to catch. After a few tries, it does start, but typically dies after 30 seconds (my understanding is that that's how long the cold start high idle runs for). Additionally, it's been having a tendency to stall when I push the clutch in and the RPMs fall, especially when cold. No fun having to restart the car at stop signs!

Additional details: this car has no air pump, there's a slight but not major vacuum leak, I've replaced the plugs, wires, and alternator... Any ideas?

satch

iTrader: (1)

The high rev start, when the temperatue conditions are right, will last for only 17 seconds and the rpm's would drop from 3000 to about 1500. The high rev cold start only occurs when the radiator fluid is above 60 or so, thus it's not going to activate in cold weather. You might want to check the Water Thermosensor at pin 2I. W/key to on it should read 2 to 3 volts w/the engine cold and eventually drops to .4 volts fully warmed. This sensor provides additional fuel on cold starts and might be a factor in your situation. You also might just have a tired engine, which requires longer warmup times. As far as the clutch is concerned, it could be a BAC problem or the ECU (pin 1L and should read 12 volts w/clutch depressed and below 1.5 volts w/clutch released w/key to on) is not reading the clutch switch signal properly. Load is placed on the engine which could lead to the engine stalling out. Setting the idle a bit higher than the factory established setting might be of benefit. And vacuum leaks are not helping the situation either.

themadninja

I will check all of these places, and see what I can come up with.

One thing I'm not sure I was clear enough about is that it doesn't stall every time I push the clutch in; it's only when I'm rolling and the engine's at higher rpm's, then I push the clutch in to come to a stop, and the rpms rapidly decline and it stalls.

I'm not sure how this might be related to or not related to the tendency to stall when I first start it up (which it does at the 55 second mark in the video). I suppose either way raising the idle speed would help.

satch

iTrader: (1)

When it stalls due to pressing the clutch in are you coming to a very abrupt stop or a rather slow rolling stop? And does the stalling occur whether the engine is warmed up or not?

themadninja

I'd say more a slow rolling stop, and it tends to happen more when cold but I have noticed it doing it when warm as well.

satch

iTrader: (1)

A cold engine will be more finicky than a warm one so take this into account as any idling problem will likely be more apparent w/the engine cold.

DennisH

I have a few thoughts on this issue, which I myself had (or at least something similar).

My issue came down to a starter that worked maybe half of the time, and a bad alternator, which meant my battery usually wasn't charged. This made it especially hard to start in the winter time. Another thing to try, if you're aren't already is to press the accelerator down which starting, and not the brake. It's extremely difficult for me to start my car without doing so.