Hi Guys,

I have been having a problem with my car dieing occasionally. I recently put in a light flywheel. Now the rpms drop very quickly when I depress the clutch. Sometimes the engine dies. I checked the dash pot, and it was not touching the throttle return when it returned to the idle position.

I read the workshop manual for the adjustment instructions, but I am not sure if it should be replaced.

I am wondering how far the white button on the dash pot should be sticking out when it in not in contact with the throttle return. Mine sticks out about 3/16ths of an inch. Any help would be appreciated.

Thanks, Adam

 

I am asked this question a while ago, and posted a pic of my dashpot, but no one really answered my question definitively. I would say yours is probably gone, 3/16th of an inch is pretty short. You can check out this picture of my dashpot, if yours is as short as mine, you most likely need a new one. Mine is stuck in just about all the way now. I'm still waiting on the part. And, of course, this part is outrageously expensive from dealers (~$100) and none of them will stock it. This is the thread I posted my picture in. The shop manual says the rod should be touching the throttle bar at 2800 rpm. If you can't get it to do this by loosening the locknut and adjusting it; you need a new one.

 

Thanks for the info. I adjusted mine as per the factory manual, but its nearly at the end of the adjustment. I does work, but I dont think it sticks out far enough to do what it is supposed to. I guess I'll get a new one.

 

it should stick out abut 1/2 inch....
and it should slow to get in, and quick to come out....
They are not over $100.
autocross your car and get replacement for around $20+ from mazdamotorsports...

 

I'll ask my hookup and see what he can get it for.
Ryker

 

I don't think it's the dashpot. The dashpot is there for when you rev it it settles down to an idle and not just fall down to 850rpms. That problem that you are having sounds like the clutch switch thing sensor everyone has had a problem with. I have never had the problem so I do not know to much about this but others do.

I had a problem with my dashpot before and this doesn't sound at all like the problem, but who knows...

 

Well, I just ordered a new one from Mazda Motorsports. $60, and on back order. 2 weeks to 3 months for delivery.

I looked in the workshop manual under section F specifications for the dashpot (page F-11 in the 95 manual). It lists the number 8. I don't know what that means. I hope that it means it is supposed to stick out 8 mm. Mine is about 4 mm.

I guess I'll find out when it arrives. I'll make a post at that time.

Thanks for everyones input.

 

Please check the clutch sensor thing. This has gone out on tons of guys having problems similar to yours. God I wish I knew the name but a search will clear that up with you.

 

Street king, I know the part you are referring to. How do I check it to see if it is working properly?

About a year ago, I didn't like the way the clutch pedal deactivated the cruise control. In my 82gsl, just a touch on the clutch would shut it off. I looked at the switch you are reffering to. I cut off part of it in order to get the clutch to disengage the cruise control without having to push down very far. I had no problems with it after that.

Adam

 

The clutch switch he is talking about is the one mounted closest to you when you stick your head down under the dash. $28 CDN I think, cured my stalling problem in 5 minutes. The Power FC was particularily sensitive to it not working, but luckily the PFC switch page tells you if it is working or not. Took 2 days to get one.

 

I'm really thinking that it isn't the clutch switch. I had no problem until I replaced the flywheel with a lighter one. Maybe I should replace it anyway. It's not an expensive part.

 

Your revs drop faster now, so it is harder for the ECU to compensate. Without the clutch switch it is even harder.

I had no problems until I put in the PFC. The switch was broken before, but on a stock setup it wasn't noticeable. I sold my PFC to another forum member who started having exactly the same problem. His clutch switch was bad too, but he didn't notice before either.

With a stock engine it doesn't seem to be that critical. Your flywheel change is related in a way, because it affects the way your car comes down to idle, and without the clutch switch, your ECU doesn't know to give that little shot of gas to keep the car running when the revs drop to idle suddenly.

 

So how do I know if the switch is bad? Is there an easy way to test it? Maybe I should look at my shop manual.

 

I looked up the test procedure for the clutch switch, and tested it. I get current across the switch when I depress the clutch, so the switch is working.

Any other suggestions?

 

Adam:

I am in the same situation you are, SR flywheel and PFC. I have replaced both my clutch switch and my dashpot and it still drops to about 600rpm and comes back up to idle. I can't seem to get rid of the dip when I come to a stop and push the clutch in, I have adjusted and tweaked just about everything. The new dashpot didn't do anything for me, I did have stalling though before I changed the clutch switch and that fixed it. Seems like yours checks out ok though..

 

It doesn't stall very often, and it doesn't appear to be at any specific time. Do you remember how far out your dash pot button stuck out on the old one, and how far out on the new one.

Did you ever call SR to ask them about it?

 

Well with my bad clutch switch it was stalling at almost every stop, it was easy to tell it was shot when I looked at it. The dash pot was pretty shot too, it was only sticking about maybe 2mm and wouldn't even hit the throttle stop when adjusted all the way up.. if that makes sense. The new one sticks out probably 3/8" or so. I never called SR about it, I think it is just because of the mass lost on the new flywheel.. probably just comes down too fast and the ECU is trying to catch it. I'm sure someone else has had this problem with a lighter flywheel.

 

Would raising the rpm that the PFC turns the injectors back on help? I'm not sure what this setting is called -- decel something. Have either of you tried that?

 

Thanks for the info on the dash pot button. Mine sticks out about 4 mm. Looks like it should be about 8mm.

I called SR and asked about the problem. They said they never heard of this problem before. I find that hard to believe. The guy suggested setting the idle at around 800 rpm. I have already done that, and the car stalls less frequently. Hopefully the new dash pot will resolve the problem.......when it arrives.

Thanks, Adam

 

I think I know what you are talking about, it is in the idle setting screen.. I can't remember the name of the settings though. There has been discussion about it in the PFC forum, I have adjusted that too to no avail. It works, but it doesn't catch the revs when they first come down. It I adjust it to 1200rpm with my idle set to 850 it works like this:

1. roll to stop, push in clutch, revs stumble do 500-600rpm

2. motor stays running, idle comes up to 1200 rpm

3. momentary pause and the idle will slowly come back down to 850

I just gave up and lowered that setting back down since it wasn't doing much for me other than raising the idle up at a stop for a couple of seconds, but not when I needed it to. This was with all emissions removed, no vacuum leaks, air bleed sockets are fine.. I am still