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-   -   Start Up RPM problem (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/start-up-rpm-problem-38633/)

GTU bad boy 12-13-01 03:33 PM

Start Up RPM problem
 
I just bought my RX-7 last summer and the warm up phase was fine. It would go up to 3k rpm and stay there for maybe 10 sec and go down. Now that it's colder outside, when I go to start it in the morning, it doesn't do the usual warm up thing. It just idles very rough at about 1500 rpm and smokes for a few seconds. It eventually smoothes out though. When I get out of school and its warmer it starts up normally and goes to 3K. Whats the deal? Is this a prelude to some serious engine problems?

Node 12-13-01 03:57 PM

I know the reason for the 3k RPM jump is because it is getting the catalytic converters to operating temperature. For emmissions only. You can get rid of that if you don't have cats anymore, I'll find the website
No idea on the rough idle

Node 12-13-01 03:58 PM

Here you go
 
http://2ndgenrx7.freeservers.com/cgi...5/3000rpm.html

HAILERS 12-13-01 05:48 PM

Prelude to engine problems? Nope. The smoke is an indication that the engine has some miles on it and your leaking some small amount of oil past the O'rings. Not a big deal in itself. I have some reservations about that post on disableing the 3000rpm start up for 17seconds. If you disconnect the wires as stated, you effecting more than the 3000rpm warmup for 17 seconds. Your affecting the relief solienoids on and off schedule for the air control valve, which may cause you t0 have some small difficulty passing emissions, if you have to worry about such things. Just a thought. Now why it does not rev to the 3000 figure is another thing. It could be the temp sw at the bottom of the radiator making a bad contact, a bad relay. etc.(etc covers a lot, good filler when you forget the name of the valve that opens for 17seconds to cause the high idle). Nothing you wrote indicated what I would call a serious problem. You should fix that idle problem just to get to know the car.

cymfc3s 12-13-01 05:53 PM

HAILERS is right, dont disconnect the AWS. I wouldnt worry too much about the cold start 3k, sometimes when its really cold, it wont jump to 3k. Anyways, with my cars, i put the car in gear immediately to drop the revs down.

GTU bad boy 12-13-01 06:33 PM

How long should I let my car idle in the morning on cold days. The previous owner said he let the car idle for about 10 min before getting in and driving. Should I even let it warm up at all? I live in New Jersey if that helps.

Node 12-13-01 07:26 PM

I thought you wanted to let rotaries warmup before getting on them hard at all times, and for short trips if you didn't let it warmup/cooldown it would flood?
Anyone care to help explain

natedogg 12-13-01 07:41 PM

Node
 
I drive my car to work and back (12mi roundtrip). I also drive it to school and back (2 miles round trip). I never let my 7 warm up except for MAYBE 10 sec. I have never had a problem with it flooding on me.

Just a little FYI

Node 12-13-01 07:48 PM

is flooding a problem with all FCs or just a certain model and series?

darkwaveboi 12-13-01 08:06 PM

My car does the same. When its colder outside, it starts, jumps to maybe 1000rpm, drops down to maybe 250rpm for 2 seconds, then goes back up to 1000-2000rpm. My car often when its starting up has white smoke come out of the exhaust. since i opened it up (hks hiper 3") the smoke billows out for maybe up to a minute after i start it up, then 'I' dont see the smoke anymore, even on hard driving. i have 140090 miles on my car (yes i keep track =) and when i got it, it had a NEW motor (3 years old, $4150.00) around 28000 miles on it. So either the guy who had it before took crap care of it, or the motor itself is a POS to start with. oh yeah, i change the oil every 2000 miles if that helps.

Scott 89t2 12-13-01 09:14 PM

letting a car idle for too long (over a couple mins) is bad for it. start it up and wait a min or so. then just drive under 3000-3500rpm at 1/3 throttle max or so till it fully warms up. I also take a slightly longer (and flater) way to avoid going up a couple bigs hills when I leave the driveway dead cold.

Erik 12-13-01 09:33 PM

yeah, i agree with scott...let it warm up for a minute or so but not too long...

just leave your car in gear so it never jumps up to the 3K range.

HAILERS 12-14-01 11:30 AM

I have come to believe that they come up short of the 3000rpm on really cold days due to the thick oil in the engine and transmission. If you don't like the 3000 just do like they say and put the shifter in gear for a moment or two. On a NA you can disconnect the plug from the AIR BYPASS SOLENOID VALVE that is located on na's b/t the dip stick and the oil pressure sensor. Round barrel shaped. That should only effect the 3000rpm and nothing else.


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