Warm Start Problem
 

Sometimes my stock '93 won't start when the engine is warm. It turns over but won't catch. It finally catches when I apply a little throttle, which I hate to do because I don't want to flood it. So far I haven't, but eventually my wife will. Any ideas?

Change the fuel filter...

Yeah. Get the Fuel Filter changed. My FD takes a bit longer to start when it's warm too. (I did do a fuel filter...) This seems to be very common with FD's. I forget if there is a real fix or not..

Check your compression. Having trouble hot starting is a good indication that you have low compression and your engine is on its way out.

I agree you have low compression

Thanks, I will check the fuel filter. I hope that is it rather than low compression, I would rather not replace the motor right now. I have been playing with RX-7s for about 10 years now but I have only had the FD for about 10 months and I am still learning about is's eccentricities. It has 110,000 miles on the odometer, but I can't find the tag with the engine I.D.# to see if it is original or not. can anyone tell me where to find this? It is easy to see on my FB and FC.

yup. mine is hard to start in the summer if you try an start it up within about an hour of the last time u shut it off. i brought it to dave at kdr and he said the compression is low. this was about 5,000 miles ago and mine is still running without a rebuild. - steve

I had the same problem, and it wasn't the compression on the motor. Turned out I had a semi-bad H20 thermo-sensor. It caused my PFC to go rich, and would flood the motor on hot starts. Do you have a Power FC? Or are you running an OEM computer? If I were you, I would check the voltage on the water thermo sensor, It's the one at the back of the waterpump housing. Let us know your findings.

eric

I am running the OEM computer. My only mod is a downpipe. The hot start problem only happens about 75% of the time.

Just get your compression checked and it will tell you where you stand. It is expensive but it might keep you from chasing all of these other gremlins.

I have kind of the same problem, I assumed it was just from heat soak. Only happens to me if I try to start it within like 5 mins after shutting it off when it's been run for awhile or hard. No problems starting besides that.

Add my name to the list as having the same problem. Mine has never refused to start, but when running it has a very surging idle. Only happens on warm starts. I also thought it had something to do with heat soak and was going to look into playing with water temp correction factors on my PFC.

hapa,

What should we look for on the PFC? A specific voltage or just that the sensor is reporting at all?

-Scott

a compression test is really easy
shouldn't cost a lot

plus then you can make future plans for the car
if you want it to last a while on low compression drive it really really really nice I would say

I actually couldn't find the problem with my power FC, the Voltage was intermittent. So, I replaced my factory ECU and the check engine light came on and showed the code for h20 thermosensor, I think it was code 11. Anyways, I changed out the sensor, put the power FC back in, and haven't had a problem since. You can check the voltage in the sensors menu, and compare to the Factory Service manual.

eric