Hello,

My 91 convertible used to do the rev to 3k on a cold startup, but now it doesn't. Is this a sign of something or anything to be worried about? (P.S. I start the car in neutral)

Thanks,
Jesse

 

nah bro... nothing to worry about ur ecu just gave up on the cold start... be happy ur engine wont hvae to rev up to 3k ... is worthless anyways.

 

I don't think the cold start works if its really cold out. Mine doesnt work at any temperature below about 45.

 

i wish mine would stop working....

 

If you start the engine with the clutch pedal pushed in the cold start up procedure won't happen. This also takes some load off your starter motor and so everyone is happy.

 

Like the above post said, at low water temps, it is not supposed to work.

If you look in the online series five manual, you'll see that the clutch switch and the neutral switch are involved along with the water thermo switch, full range tps circuit. You might suspect the neutral switch first. If the water thermo switch was bad you'd get a code and you are not getting that or you would have said something.

On a series four car, you have a water temp switch at the bottom of the radiator that controls the high idle at startup. If the water temp is below 62.6 F, the high idle speed won't happen until the water temp gets above that figure.

 

How important is that water temp sensor at the bottom of the radiator? My 3k start hasn't worked regularly since I got the vehicle, and a couple o fmonths ago I noticed the wires were frayed, and now one of the bullets snapped off at some time.

 

Don't worry about it not revving to 3k on start-up. That's just to heat the cats up quickly to keep emissions down at start-up. It's always seemed foolish to me to rev an engine that fast on start-up, because the oil has drained out of the filter (upside-down filters on these cars, and no anti-drainback valve in them) since the car was last shut off, so it takes a few seconds for oil to get properly distributed throughout the engine.

 

That water temp switch at the bottom of the series four radiator does more than the three grand startup. It effects the Relief Solenoids operation also. If the wires are broken or the switch itself is defective internally, (not likely) the relief solenoid will not be energized when it should be and that will effect emissions which are important if your trying to pass emissions.

A quick soulution is to just couple the two wires/bullets together to simulate a warm/hot water situation. One of those wires is a ground. The other to the ECU. The ECU is looking for a ground thru the switch when the switch makes. Tie them together and you've done that.

The above is in the free, online, fsm for the series four.

 

Mine has not worked since I bought my car and Im glad for that he he

 

i like my cold start up cause it keeps the revs high enough so my car wont die

 

mine works at the most random temps, it does that at 75 to 80 degrees outside. i think my rx-7 is just special.

 

Cool, I'll do that then. I have tried to repair the swithc, but it broke too far down. I don't know how much longer my relief solinoid is gonna be there anyways.