Hi, I have a s6 Rx7, runs good during the day But wont start very first thing in morning. Can take 5min to start it in the morning when left out over night,but once its had its very first start of the day even if its for a second it will start up fine after that. If garaged overnight seems to start easier, also wont idle when cold but comes right after a couple minutes. Why is this? thought if might be compression but then wouldn't it have issuses starting other times not just very first start of day? spark plugs look fairly new also. Any help is welcome, Thanks
tony9,
Mar 31, 6:33am
Faulty temp sensor. ECU thinks it is up to temp all the time.
rob_man,
Mar 31, 6:39am
This is a trick a car dealer showed me, if a rotary won't start cold you tip a couple of teaspoons of brake fluid down the vacuum hose from the booster to the inlet. Don't ask me why or how somebody figured out to try it but it works.
bayview1,
Mar 31, 6:43am
Temp sensor could be reason for idle but not starting correct? Is there a way to test it before buying a new one? I have also heard the brake fluid trick but how long does it last? Don't won't to be doing it every day. Cheers
tony9,
Mar 31, 7:16am
Faulty temp setting will make it hard to start cold as there will be no mixture enrichment.
Have a google around, you should be able to find the appropriate resistance of the sensor. If it is not within spec then likely a new one will fix it. Also check the wiring and connection to the unit.
mechnificent,
Mar 31, 7:30am
Has it had a tune ? Are the plugs and/or leads good ?
mechnificent,
Mar 31, 7:32am
Does it crank faster when it's been in the garage over night ? Is the battery and starter good ? Charging?
bayview1,
Mar 31, 7:35am
The plugs and leads look good, no hasn't had a tune. Where the accelerated cable goes into engine bay and connects to the part that pivots (unsure of name) there is the same part with nothing connected to it, should there be? Was thinking it could be for a choke cable or something? Sorry if that makes no sense
bayview1,
Mar 31, 7:38am
Cranks the same, don't think its battery or starter, have no trouble with starting after its had first start of day. Someone said could be compassion issue but wouldn't that effect issues every time?
mechnificent,
Mar 31, 7:41am
I'n not familiar with mazdas sorry. If there is an extra cable fitting it's likely for a cable to the auto trans.
This car doesn't have a carburettor does it ? It will be fuel injected surely. In which case it won't have a choke.
mechnificent,
Mar 31, 7:45am
Spark plugs getting damp and leaking the spark away around the outside possibly. Start it at night and then give it a tiny mist of water near the plugs and/or leads.with the hose while watching for sparks. You won't get a shock. If the leads are good it should stand having the hose turned right on the leads and caps.
mechnificent,
Mar 31, 7:47am
You could try the plug gaps at one end or the other of their recommended range of gap setting. Some cars are quite critical of that and it can show up in cold starting or misfiring at idle even though they run and pull just fine.
bayview1,
Mar 31, 8:14am
Thanks ill try the what it is also factory manual. Unsure if you can adjust plugs as they don't look like normal plugs on the end
rob_man,
Mar 31, 8:19am
The brake fluid trick is only a way to get that first cold start to happen and it should start again after that. The downside is that it indicates a loss of compression but at least it gives you a place to start looking.
mechnificent,
Mar 31, 8:22am
Oh ok. If you can't adjust the plugs, you can probably buy other ones the same with a different preset gap. but they are dear and not worth it just for a try. Sometime a slightly lean mixture such as at idle or when cold, can need a smaller gap to make it hotter, or a larger gap so it has more chance to light the fuel.
Try the water. It's probably cold and condensation that's causing your problem.
bayview1,
Mar 31, 8:41am
Sweet thanks for the help
piperguy,
Apr 1, 12:02am
If it is like the older style 13B in my Series 4, the plugs can't be gapped, they have a weird end on them without a protruding tip. There was also a common fault with the older engines where they would refuse to start if they were a little bit warm, it was to do with the temp sensor thinking the engine was still cold and flooding it, everyone I knew had switches installed to disable the cold start function. I would imagine based on that your problem is electrical in nature.
intrade,
Apr 1, 12:14am
that seals the combustion chamber up for a rotation. wankel are notoriously knowen to blow gaskets , You need to do research no short trips on wankel or you be ending up with big problems also due to the way condensation etc forms and how a wakel functions. i personally dont like them much to inefficient for me
timmo1,
Apr 1, 6:08am
It'll be the cable for the cruise control (which your car presumably doesn't have)
jummybuffett,
Apr 1, 6:15am
try holding your foot flat to the floor next time you cold start it. and release when it fires. if this works it will make it easier to diagnose
loose.unit8,
Apr 1, 6:27am
There is a very cheap generic replacement plug which is of the normal car style so it's possible there may be plugs in there which have a gap.
FYI in FDs, wide open throttle while starting turns off the injectors so the car can unflood itself.
loose.unit8,
Apr 1, 6:30am
bayview1, there's quite a bit of troubleshooting info on these sites maybe it might help?
Correct the plugs can't be adjusted, also its fine starting when its warm I have no issues there. It doesnt have cruise control and I don't think any model comes out with it so would that still be for that? Cheers for the link. Also spark plug leads seem fine
loose.unit8,
Apr 1, 8:32am
Would engine pics help ID the thing which might be cruise control? I found ones of the S6 I used to own http://imgur.com/a/yZOIZ
jummybuffett,
Apr 1, 9:25am
exactly
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