Hey all

I have a ‘90 RX-7 with a strange idle, it sometimes pulsates, sometimes runs steady around 950, sometimes (usually when the car is cold) idles at 2000. And sometimes it pulsates so bad between 1000-200 that it nearly dies getting so low. I took it to a mechanic who adjusted the tps twice and told me that he doesn’t think it’s a tps problem because it keeps losing idle after the tps is adjusted. The next day he tells me it’s a problem with a “wax pellet” which he described to me as basically a thermometer, and that it only has a quarter inch of movement when it is supposed to be moving more I guess. He wants to charge 500 dollars for the repair. Anyone know if this is a fair amount? It feels like a lot to me but I just want the car to run correctly so if it’s honest I’ll probably just pay up. I have an itemized bill of everything if anyone wants to see it.

 

If you live near Kilo Racing in St Cloud take it to him. He will not jerk you and he will fix it. If your down South take it to Cam at Pettit Racing.

 

the actual wax pellet N326-13-W87 is $111 from Mazda. it is pretty quick to change, but then you need to check the TPS again, and the wax pellet adjustment, i'd do 2 hours for that.

what is going on is that this pellet pushes the throttle open when the car is cold, it is what gives the fast idle.

if the car is warmed up, and the pellet is stuck, it will either idle high, or as you've discovered the ECU will hunt for the correct speed, and if it doesn't find it, it'll surge and do other strange things.

 

so this sounds like an accurate diagnosis? And the price that he is charging sounds accurate as well? I am perfectly fine paying as long as the price is honest and fair. He is charging 390 dollars for the replacement of the pellet, adjustment of throttle and TPS. And then he’s charging 122.78 for the part

 

i think diagnosis is accurate. 3 hours is a lot of labor time, but it is an old car, and the chance of needing all 3 hours is pretty high.

 

at 3 hours that’s like 130 dollars per hour no? It’s my first time at a mechanic. Isn’t that a lot of money?

 

yes, its $130 an hour. the second part is a judgement call. what is a lot of money? 130/hour is cheap around here, they are up to $200+ (which prices them out of a lot of work...)

 

 

Yeah, then there's another $2500 for a valve job and $1500 for replacement muffler bearings.

 

Full detail Automotive in Tampa is a pretty good shop. They specialize in the FD and rotary stuff and just 90s Japanese in general. Not sure where in Florida you are. Its likely they can do better than what you're guy is telling you. If hes talking about the wax pellet in the front of the e-shaft, that has nothing to do with idle. Most people delete them. If hes talking about the wax pellet in the iacv, it would be pretty straight forward to troubleshoot. Idk about this one. I think he might be throwing parts at it

 

appreciate your comment. Im about 45 minutes from Tampa. I might go check them out.

 

thermowax is in the throttle body...

 

oh... its ON the throttle body for the FD. i guess you guys are a little different. also now realizing i said iacv...