Hello,

I own a 93 touring rx7.
Car has low miles with a Down Pipe and Cat back exhaust.

On a cold start up the car stays at 1100 rpm until i have driven for about 2-3 mins.
Is this normal?

Also when i rev the engine in when the car is stopped, the rpm drops down to 100 then jumps back up to about 750-800... what may be causing the dip in RPM after reving the engine from a standstill... ?

 

not sure about that second part but when cold the car idles higher to warm up faster

 

Thanks for you replay..

For the second party...
When you rev you car what rpm does it drop down to when you let go of the gas?

Usually it drops to 100 rpm, sometimes almos stalls on a hot day that is, and then goes back to normal rpms.

 

If you have stock ecu, stock intake etc. Check you idle vacuum and do a compression test.

 

The first line on the tach is 500rpm not 100, which is probably what you mean, you need to adjust your idle adjust screw under the intake elbow. Turn it all the way in, then back it out 1 to 1 1/2 turns, this should be good(you may have to play with it a little). I have yet to set idle on any car that stays perfect, especially once modded.
Art

 

My car starts at a high idle sometimes. I just blip the gas and it comes back to normal.

 

1100 is normal for warmup, even without the accelerated warmup system, your car should be around there for the first few mins.

as far as the second problem i think rts3gen is right, you might just be looking at the wrong line, but you still shouldnt be stalling, you might have a loose vaccuum hose somewhere

 

Ralgh my car does that too mine will shoot to 2500 and stay there untill i pop the throttel

 

Just start the car in gear if you have a manual. That disables the accellerated warmup system and prevent you RPMs from going to 3k immediately after starting. Which just can't be healthy for any engine...

 

yeah its definitly not healthy... imagine all your oil is in your oilpan, and you're revving to 3000rpm

 

yeah, i have never let the car enter aws..i start the car in gear, it idles to around 1500rpm, for a few minutes if its cold out but then it goes to about 1100..then like after 5 minutes, it sits at around 800rpm..

 

my idle is something like that too, give or take a few hundred RPM's.

starting a 3k rpm's is kool, everyone is lookin at ur car because its rev high then its blows off. i dont think this could be that bad for rx7's if bad at all because alot of rx7 drivers dont put there car in gear while starting up and doin this everyday for the next 5 years of the rx7 life. if it was a bad thing i think majority of rx7's would of died from the problem alone.
Timmy

 

i think the concern is that suddenly jumping your revs up to 3k on a cold start creates unnecessary wear and tear on the cold motor. sure it won't blow up your motor but it's rough on the moving parts. same reason you don't redline any engine immediately after firing up cold, just common sense

 

There is a wax rod that expands as it warms. That moves a cam on the throttle body that lowers the idle as it warms.