I just recently bought an 87 rx7 non-turbo for my stepson and i have been trying to get it sorted out before turning him loose in it. The problem is, I cant get it sorted out.

1) I can start it in the morning and it will flucuate its idle from 950 to 1500 and eventually rest at 750. I was able to get the idle adjusted to 750 but the cold start up and down scares me.

2) I can be driving along and all of a sudden i start to loose power. Not all the time but once every three days or so. When you step on the accelerator it starts to stumble badly. I can lightly put my foot on it and it will only rev to2000rpms or 2500 at the most before it starts hesitating. So i had to drive home at 23mph this evening. Now tomorrow when i start it up it may drive fine and may idle fine.

3) some days on cold start it wont idle at all. it will jump up and down between 500rpm and 350 until it stalls. It will restart without problem but i will have to hold my foot on the gas. But as soon as i can get it to rev to 6500 rpm it will run just fine and idle at 750 beautifully. But there is no telling what it will do after i am 25 miles away from the house. i went to the autostore this evening and it ran fine. Once i got back in the car to come home it wouldnt idle.

So my only option left was to lay my hand on the hood and start praying. Does anyone have any ideas? i would appreciate it. Because i think the car is possessed.

by the way its an automatic.

 

start with a full tuneup. the power loss and stalling could be from a dirty/clogged fuel filter. for that matter clean the entire fuel system (lines, injectors, etc.).

 

I did all of that already.

By the way i went out this morning and it started right up. Idled at about 1250rpm and slowly came down to 750 as she warmed up. Then i let her sit there and idle for about 30 minutes and she sounds like a kitten.

I'm wondering if there can be some sort of electrical short.

There was one problem when i first turned the key. The fan came on as though the car was hot. and once i gave it a rev to 5000 rpm the fan shut off. That was weird. But other than that i am stumped.

 

that RPM fluctuation probobly because of your TPS sensor..i believe.. if its bad..or Disconnected your Idle will jump up and down..its conncted right next to the Throttle body area..

Redline it =D clean out carbon..

 

i second the tuning of your TPS , my 7 used to idle bounce to when it was running also could be a vacuum leak ?