I have spent a bunch of time searching trying to find a common problem to mine and found nothing.
They all seem to be the same cold start problem of poor compresion and flooding and my problem is not like that
ok here it is
my 88 rx7 base model takes about 15-20 mins of turning over not touching the gas to get it to start when the physical outside temp is below 32 degrees but as soon as it hits the 33 degree mark out side the car will start on the first try.
now first thought is battery so i bought a new upgraded one with 650 cca compared too 550 cca stock.
No luck still same thing. although it now only takes 10-15 mins of cranking over. (i recently discoverd that if i tap the gas lightly in time with the turning over it will start quicker so i tried gas line antifreeze, still not better)
I know its not flooding because it will always start with out doing any un flooding procedures (and if you do the unflooding stuff like egi fuse it does not help), jumps to 2300 rpm, warms up real quick drops to 800 rpm idle and runs just fine.
Although it sounds like a birdge port while warming up. but i have not heard a warmed up idling bridge port so i dont know if it sounds right after warmed up. because it idles real smooth.
I dont know about compresion because i have not had the time or money to take it and get it test but it has wicked big ***** of the 3 N/As i have driven its definatlly the fastest and has a real hard time hooking up and keeping traction above 50% throttle even with the brand new tires on it. Which would lead me assume that it does not have a compresion problem.
I guess it wont be a big deal once winter ends but its frustrating right now.

a little background i rescued this car from some drug addict who took very poor care of it and it has no emmisions and no cold start stuff, a straight pipe back from the manifold for exhauhst and who knows what else is wrong besides that it is an electrical nightmare.
i had to replace all the brakes and i am in the proces of replacing the suspension.

i guess it could be a fuel pump problem but i never have loss of power once its running.
If anyone has any ideas as to why this happens it would be appriciated thank you
Luke-

 

also sometimes it takes so long to start it will kill the battery. not so much recently but before the new battery

 

On the back of the water pump housing (near the alternator and thermostat housing) is your temperature sensor that goes to the ECU (which is separate from the one that goes to the gauge in the car). It has a [faded by now] green plug with a little metal tab thing around it like a fuel injector connector. Make sure that it is plugged in securely. If this sensor is not working correctly the ECU will not inject the correct amount of fuel on cold start (especially if it is disconnected. then it will assume the engine is warmed up).

If it is in fact plugged in securely, you may consider replacing it. The sensor is around $40 from the dealer or mazdatrix.com , or you can get it from a parts store (which I've never done) for maybe $20.

 

cool thanks ill check it out

 

yeah it definatly was not even pluged in and the car runs so much better now. i dont know aboujt starting because it is warm out right now and it started right up before i check the plug but it runs smooth from the start now no choppy idle while warming up thanks much

 

this could be a problem or might not but it sounds like it is.

 

well i dont even know where to start for putting all that stuff back on. because i didnt take it off so i dont really know whats missing its just a guess really ike parts of the cold start are there but parts arent same for the emissions like i have all the cats but i dont know what else might be missing and whats not. if i could find another car to park next to mine that was stock i could see whats missing and the buy the stuff but i dont have that option.

 

well ive heard as well on the cold start thing that over time the rotor housing begin to wear off the lining on them being the reason y you have to tap the gas to get it to start. i have a similar problem with cold and warm start. i have to push the gas down slightly to get mine started. but i havent found out to much of why i have to push the gas down. mabe mine is the same problem you had the sensor that you were talking about where would it be located on a 90 s5??

 

on a stock car, you have a bunch of stuff like the air supply valve, bypass air control valve, cold start thermowax, etc. that allow additional air in for a cold start.

 

man i wish i had all that stuff back its so frustrating trying to fix stuff that someone else butchered. i just want a stock rx7 and i would be a happy man lol. then i can go about things the right way.
as for worn rotors i dont know about that, the kid who owned it before me had the recipts for the rebuilt motor that is supposedly in the car and it only has like 50-60k on it since then with regular oil changes. but who knows. it does run real strong for something that might be worn out.

 

thanks to everyones suggestions it starts right up now but it still idles funny
oh well at least it starts no problem