R1 POWR

Sorry for yet another thread on a stalling RX-7. I've searched and read....and read....and read, and I think my eyes are starting to cross. I didn't see an immediate thread on my exact symptoms, but it's late, and I probably missed it. Anyways, here's what's happening:

A little background on the car.....it's not a daily driver, so it gets a lot of "rest". Most of the time, I'm carrying kids to school or wherever, so I can't drive it. However, I absolutely refuse to sell her off...........it's just too much fun to drive :-) Anyways, a month or two or three ago, I noticed it would stall at idle when I turned the AC on. This was something new. With the AC off and even lights on, it would idle fine. A few weeks ago, while on my way to Mazda to get an oil filter to change the oil, I accelerated a bit hard after leaving the neighborhood (car probably wasn't fully warmed up). Car seemed fine for the next 4 stoplights, but while waiting to make a left turn into the mazda dealership, she stalled on me. Odd, but I cranked her back up and pulled in, where she stalled on me again (perfect timing....customers on the lot looking at cars :-). Cranked it up again, pulled her into a parking space -- having to keep the RPMs up to keep her from stalling -- then just let off and watched her stall. Weird. Went in, got an oil filter, came back out, cranked her up, and she was idling fine. As soon as I started to pull away, low idles got shaky and felt like she wanted to stall. I just kept the RPMs up, got some oil, and headed home. Changed the oil, cranked her up again, and she idled fine. Started to pull out of the driveway for a test drive, and she stalled on me again. Cranked her back up, and pulled her into the garage, where she sat while I did some thinking. Fuel filter? Blown apex seal? Plugs? Vacuum hose? Fuel pump?

Note, car was on EMPTY (gas) -- no light on, but gauge on E, when all of this happened. Not sure if that's relevant, but thought I'd throw that bit of info out there.

Well, I got 2.5 gallons in a gas can, and added that to the tank, thinking maybe it was a dirty, clogged fuel filter. Some days later, I changed the fuel filter (my first time....lots of fun....highly recommend it, especially if you love the smell/feel/taste of gas :-) After fnally getting it started (thought I was going to have to resort to the starting fluid, but luckily didn't have to :-), basically the same symptoms -- idled fine after finally getting it started, then eventually stalled. After starting it again, a quick test drive thru the neighborhood seemed promising....no stalling at the stop signs, but eventually started stalling again. Said what the hell, and took it for a long drive on some major roads. Seemed to run fine as long as I kept the RPMs up at a stop. I avoided roads with any stop lights, as much as possible. Did a few boost runs in 2nd and 3rd, and she still runs strong and smooth, with good boost patterns (as far as I could tell). Drove about 30-miles, and filled her up with gas before heading back home. The way she ran, I'm thinking this ruled out blown apex seals and bad fuel pump.

I'm almost at a loss. I think my next move will be to check the clutch switch. However, I never really noticed if the stalling was correlated to the pressing of the clutch. Should be an easy thing to check. After that, I'll probably change the plugs. They haven't been changed in awhile and probably need to be changed anyways. With my current mods and PFC, she runs really rich -- as evidenced by my 11-12 mpg :-). I've been on the fence about a FMIC, and was waiting to change the plugs then, just prior to having it properly tuned. But I guess I can go ahead and change them now (maybe go ahead and get that bigger IC, too :-).

Anyone have any other ideas? Anything in the rats nest that I should look at that would cause these symptoms? I was contemplating cracking that nut, but with satisfactory boost patterns, I didn't want to "fix something that wasn't broken".........and risk breaking some solenoid nipples :-)

TPS?

Sorry for the long post, but I wanted to give as much info as possible. Any ideas or help would be greatly appreciated. I don't get to drive her much, and I've already missed about 5-6 opportunites to drive her since this started :-) And for those that are wondering, 105k miles, original engine, original turbos.


R1 POWR

spoolage

iTrader: (2)

105k on the stock motor & turbos is amazing!!!!!!!

Go ahead and change the plugs and report back. You might as well buy a cheapo compression tester and get some readings while your at it. If you recently changed the fuel filter then doing these two things will be a breeze.

It could be a number of things with that many miles on an engine but it sounds like it runs considerably well when cruising so lets hope you can make it into the record books for most miles on an OEM engine & turbos.

Getting some basic compression #'s would be a good first place to start.

djseven

iTrader: (56)

IF you are getting 11-12 mpg and it is stalling a lot that isnt promising. Still, as said above, change the plugs and that could possibly help. Sounds almost as if you have a chipped apex seal and you just need to adjust the idle up if you want to keep driving it. However, the cheap compression tester will tell you what you need to know.

When it is stalling, does it just cut off instantly or drop down gradually in rpms over the period of a couple seconds like it is fighting to stay running?