Car stalls on sudden stops
 

Hey Guys,

Was having this issue over the summer, the car has since been parked but now that the weather is starting to warm up im starting to think about the car more and more.


Anyhow, I've been having this issue where the my 1995 JDM FD will stall (sometimes) if I stop suddenly. If I pop it into neutral and coast to a stop it is usually fine, but if I have so stop quickly it stalls at times. Usually only when its warmed up a bit. After it stalls it will restart on first try with no issues whatsoever...... not too sure whats going on there? Anyone have any idea where to start looking? Compression is fine, new fuel filter, new fuel pump, new plugs/wires etc. Car drives otherwise with no problems at all, just the occasional red light embarrassment.

1995 JDM FD
Non sequenatial (rich mans) w/ ported wastegate
Power FC (running basemap currently)
catless downpipe, midpipe
3" turbo back exhaust
Apexi Intakes

My first thoughts are electrical, maybe check the crank angle sensors and wiring, and the ignition coil wires (not the spark plug leads) I am thinking that something is shorting out when you stop suddenly. One thing to rule out at the least

Mike

I say check the electrical switches down at the pedals- up in behind the pedal box there is a clutch switch and a brake light switch (from memory). When the clutch is depressed, the pedal pushes the clutch switch in, and this signals the ECU.

It may be the case that one or both of those switches are improperly adjusted (plunger length) or gummed up or electrically faulty.

You said popping it into neutral it does not happen. If this means you aren't using the clutch switch, then yes it won't stall. But a panic stop using the clutch to quickly depress the faulty clutch switch may stall it.

**Disclaimer, I have an automatic FD as my primary FD. So this is just a suggestion. My manual FD I have not gone near or sat in, for over 19 months. So use the info at own risk, etc **

Check the clutch switch for sure, you can use sensor check menu on your pfc commander to do this easily. Next check that the dashpot is engaging when it should and that tps voltages are in spec (also done with sensor check on commander).

Most likely a bad dashpot on the throttle body. It catches the throttle plates so they don't close too quickly. When the throttle snaps shut the ISC doesn't have enough time to open to provide idle air and the engine stalls or nearly stalls.

Dale

Is this a repair or replace type of thing?

Ill give the clutch switch a check! TPS voltages are all in spec so im thinking either that or the dashpot

Some people have experimented with dashpot repair, but it might need to be replaced. You may be able to find a good used one, new ones are a little pricey.

Here's a thread with some pics and info -

https://www.rx7club.com/3rd-generati...icture-903649/

Dale

Great!

Thanks Dale

Are you sure you have a stock clutch and flywheel?

Your stalling symptoms are equally likely to be due to a lightweight flywheel and racing clutch combination. Also possible that you have a poor ground wire connection.

Either way, hope you solve your problem.


Binz

I had the exact same symptoms you described and it was the clutch switch as mentioned above. PFC diag menu will allow you to quickly determine if this is the issue. I forget which indicator it is off hand, but if you engage/disengage the clutch you should see an indicator turning on/off. If not, this is definitely the issue.