carjunkie12

Hello, i have an 1986 FC rx7 second gen 13b rotary N/A. my car will idle if the engine is warm. but if the engine is cold the car will not idle. i dont know what the problem could be. ive checked all over the forums, and internet and so far i have had no luck. any ideas? also i am new to rotary engines. i have only had the car for 3 weeks.

misterstyx69

iTrader: (142)

Do you know if the car has had any modifications done to it?
Like emissions removal?

Plenty of cases where the throttle body is stripped down to basic necessities and the Cold start,etc is removed.
That make you have to keep the car running "manually"( by your foot with you in the car) until it gets up to temp.After that the car will start and idle if it is warm.

carjunkie12

no i dont know if it had modifications to anything or not. its been doing that since i bought the car. how do i check?

satch

iTrader: (1)

So, when cold, the idle jumps around as it goes from high to low over and over? You might try measuring the TPS as its Green/Red wire should read 1 volt w/key to on and the engine as hot as it can possibly get (20 minute drive should be sufficient). And is this car an auto or manual.

carjunkie12

5 speed. and when its cold it will start then immediately die. and ill measure the TPS tomorrow morning when i can see.

carjunkie12

okay, i tested the TPS and its reading 4.8 volts

satch

iTrader: (1)

Your TPS has but three wires. One is a ground so it obviously should not have any voltage. The Green/Red wire should have 1 volt w/the engine completely warmed up. And the third wire is the Vref voltage wire which is supposed to supply 5 volts w/key to on to various engine sensors. Given this, are you sure you measured the correct wire?

carjunkie12

yes, i measured the green/red wire. it read 4.8 volts. is that bad?

DC5Daniel

iTrader: (10)

That would indicate that the car "thinks" you're WOT. Either your TPS is bad, or set severely out of spec. Check the FSM or fc3spro for adjustment procedure.

satch

iTrader: (1)

The TPS has a plunger which barely sticks out when either idling or just after the engine has been turned off. Is this how yours looks?

carjunkie12

well from what ive noticed, the TPS has like a little black push like button? when you press the gas it pulls the throttle cable and then pushes that button in?

satch

iTrader: (1)

Pressing down on the pedal causes the rod to extend outward. When it's in idle position is the rod barely extended or not.

carjunkie12

before i answer that, to make sure im looking at the right thing, does it connect or touch this?

the two leverlike thing?

satch

iTrader: (1)

Yes, but is that a pic of your car, and if so, where's the TPS?

carjunkie12

its like on the bottom. right behind that. the bottom lever is touching the button. is there supposed to be something connecting the two levers? because the bottom lever never moves?

HRnico

iTrader: (7)

It appears that the adjustment screw and spring are missing as well

satch

iTrader: (1)

Agreed, and this is a pic of how it should look.

https://www.rx7club.com/attachments/...e-imag0791-jpg

carjunkie12

well then it does seem like I have a problem, lol. dose anyone know where to get one of the adjustment screw and spring?

d4rkc7owd

spray carb cleaner around the vacuum lines and manifold when the engine is cooled, not to much though and if you hear any difference in the idle you know the problem. if its okay you at least know that's out the question.

1 step at a time then tps

d4rkc7owd

forums, craigslist , etc..

RobbyWally

iTrader: (2)

I took a photo of a spare throttle body to post in your "Anyone know what this is?" thread (now closed as duplicate posting by mod misterstyx69). As I posted in that thread, the screwn and spring do not have their own part numbers. I measured 'em up so you can try to cobble something together. The spring is 8 turns, 19 mm (3/4") long and 1.2mm wire. The screw is 5mm dia x 0.5mm x 26 mm long. The very fine metric thread may be a challenge to track down.

Wish I had seen this thread before I took the time...