dludden

I've already posted on this before but going through the FAQ it looks like I either need throttle plate cleaning or TPS adjustment for worn throttle plates. I have surging idle problems on my 1985 GSL-SE between 800-1200 RPM. I also recently developed high cold idle problem at 3000 RPM and stays there a minute or two before beginning to come down. I have a mechanic who says I need new throttle body and he refuses to even consider TPS adjustment. He says RX7 club is wrong.
I think he is just being stubborn. He said this before I told him about the TPS adj recommended by RX7 club and I think just doesn't want to admit he was wrong. I don't have the expertise to do a TPS so I made an appointment with a Mazda dealer but I'm leary about going to them. If any additional comments would be appreciated. I think the mechanics help messed up the cold idle while trying to fix the surging idle problem.

RotaryRocket88

iTrader: (7)

Worn throttle plates? I can't see how that would happen. The plates don't actually touch the metal walls around them. Adjustment of the TPS can often cure surging idle problems. Sometimes the TPS itself can be bad, and a replacement can be sourced.

Does the mechanic say why he thinks you need an entire new throttle body? It's not exactly a part that wears out. Unless you have something physically broken, it sounds to me like he has no clue what he's talking about.

3000 RPM cold start is normal for approx. 17 seconds. If you start the car in gear, it should instead just go up to the 1500 RPM cold idle speed. Does the idle speed drop down if you put it in gear, or after the engine warms up?

wjk0817

iTrader: (3)

Wouldn't be the tbody in most case.
Try adjusting your tps, or replace them.
If still crappy, check for vac leak.

And the 3k cold start rev is normal, judging by my fc.

dludden

I misspoke a little when I said "throttleplates." I meant to say throttle shafts.
He says throttle shafts are worn but i don't think he really knows. He said this before i told him what the RX7 FAQ said. Even if it is the throttle shafts the FAQ still says it can be fixed with the TPS. It's either throttle shafts or throttle plate
cleaning. When I got it back from the mechanic the cold idle went to over 3000RPM. I know some say 3k is good but it never went that high before. But you say it should start to come down in 17 sec but after 2 minutes it's still high. The menchanic reversed the air adj screw a half turn to make the idle even higher but I turned it back all the way down but when I do this it seems to lose a little power.
I hope dealer on Tues can fix this. I'll try starting in gear but I don't think it will help. I usually put clutch in and keep in nuetral.
The warm idle problem is surging between 800-1200 that occured after it started dropping down from 1200 to 800.

RotaryRocket88

iTrader: (7)

The shaft seals could wear down and create small vacuum leaks, but I've never seen it happen. It sounds like the guy's just taking shots in the dark.

The air adjust screw on the TB has no effect on power. That will just increase/decrease idle speed.

dludden

I went around town a couple of times since I turned the TPS screw a quarter turn
clockwise and haven't experienced surging problems. I don't know if this is coincidental or I did something.

Still have high cold idle problem. I don't see how you can say 3000 is normal because the car drives itself that high. At least you agree it should be dropping down but it only starts dropping down after 2 or more minutes. It only goes to 2500 now but that is because of warmer weather. It still hangs up there too long.