Ok I thought I fixed this problem but its back. I had a high bouncy idle (which I guess was masking this electrical issue) but I got that smoothed out today. Now when I'm idling and turn on the parking lights, headlights, or rear defroster the car stalls. Doesn't stall with the radio on though. Earlier today I was turning the AC on and off and it was running fine but a few minutes ago I tried it and it stalled.

If i hold the revs up i can turn everything on and keep it on. If i rev to 3 grand for a couple seconds and let off the revs will come back down and idle for a second and then slowly drop and die. The car starts right back up every time. I didn't seem to notice the brightness of the lights being dependent on the rpms at all. I checked the wire going from the alt to battery and it read 3 volts (which seems normal from what i read in another thread). The battery reads 12.9 volts while off and 13.8 volts while sitting at idle with no accessories on.

I replaced the alternator with a used one i got from fritz about a month or two ago and the battery is less than 6 months old. I put a 51r battery in but I don't see why that would make a difference. I also added a few grounding wires in the engine bay the other day.

To me the symptoms seem like a bad alternator. But if that was the case why is the battery fully charged with the car off and why does it start back up every time? Do you guys have any insight on this?

 

The entire time I was reading your post I was thinking, "Alternator, alternator." I'd still check it.

 

So if the alternator is the culprit wouldn't the headlights/accessories use voltage directly from the battery? And wouldn't this drain the battery? I guess i just don't understand why i can keep starting the car right back up and have a fully charged battery.

 

check your grounds

 

i just added more grounds the other day... i dont think that could be the problem

 

Took out the alternator today and had it checked. They said it was fine. I guess I will put it back in and make sure the the belt is tight and grounds are good but beyond that what else is there to check?

 

Ok this is driving me nuts. I put the alternator back in and and pulled off some of the grounding points and scraped a ring of paint off before reinstalling them. Started the car and it was idling fine. Turned the ac on, turned the lights on... everything worked perfect. Went for a drive... car drove fine except for when the idle dips when i put the clutch in and the AC is on (i haven't wired in the clutch switch so this is expected). Pull back into my neighborhood, park the car and let it idle. Its idling fine. Flip the parking lights on and the idle dips really low and I have to immediately flip them off to avoid a stall. Same thing with the AC. Why the hell would it work at the beginning of the drive and not the end?! I think I might have to just take it into the shop.

 

I guess im having the same exact problems as you, I've gone step by step in the factory service manual and always have a f&^%$^&&* idle problem. I am an ASE certified mech. and have probably spent hundreds of hours troubleshooting. I've added grounds and cleaned grounds and checked the tps, alt, bat, leaks etc... but I have not checked the ECU in depth the BAC does read 13 ohms (above factory specs) and does seam to do something different all the time. This valve works on a MHZ frequency so small movements are crucial. Any one elses imput would be greatly appreciated on this subject because we all seam to be facing it in one way or the other, post are great but seam to be repetitive I'm going to start thinking outside the Box. There has to be a way around this problem. This web site is awsome, let it live!

norevlimit

 

You need to remember that when you first drive the FD cold, the wax rod, etc. will keep the idle a bit high until the car fully warms up, so you won't be stalling when you put a load on the engine like you would (and do) when you try it when the car is fully warmed up (that's why you noticed that "the idle dips when I put the clutch in and the AC is on" when you first drive the car...the idle is artificially high, so the car doesn't stall).

First, you need to hook up the clutch switch; while this may not be the root of your problem, it's not helping matters to have something disconnected that should be.

I don't have an FSM in front of me right now (and won't for a while), but the problem is that the ECU doesn't know that you've put an additional alternator load on the engine, so it stalls at idle with the lights or A/C on. Activating the A/C or anything that puts a load on the electrical system like lights or rear window defroster, etc, triggers a switch that tells the ECU to boost the idle to handle the extra load. Try to troubleshoot it from that perspective.

 

I realize it's not helping but when Im idling the clutch isn't pressed anyways. So in narrowing down my problem that doesn't seem to be the specific culprit (although i agree it should be connected).

Isnt it the ISC that boosts the idle? If so I already cleaned and tested that.

 

How do you know that it's actually getting a signal?

 

mmaluso, did you fixed the problem? i have the same problem with my FD. i am new to the rx7 world, could you get me some tips? thanks!

-Li

 

What is the idle speed set at? Another possible culprit is the electrical load sensing unit in the passenger side foot well above the ecu.

 

idle speed set at 800 rpm with no load. adding load to the engine it just stall. will check out the EL unit when it is not too hot outside.