Hey guys,

I had my 84 T/A tuned on a Chassis dyno after having my new 350 dropped in and it seems to be idling too low now...but only when really warmed up.

When I start the car the engine is idling around 1200 or so, once it warms up that drops down to 900ish....(closed loop I believe it the term I'm looking for). Anyway, I drop it into gear and it hovers around 650 or so...but then it starts stumbling...eventually dropping in idle until it stalls out. Now, once the car is warm (180+ with my 160* thermostat), even in park the idle will start to stumble a bit and sometimes eventually drop so low that it will stall out.

When the weather was cooler, the idle stayed semi-high, even once warmed up, around 800ish when in gear and I didn't have this problem. Any ideas?

Just a side note, I really love how the car sounds idling a 650, has a really mean rumble to it.

 

sounds exactly what we had... we replaced the throttle positioning sensor and now ours is fine.

 

does a carbed car even have a throttle positioning sensor? This wouldn't be equivilent to my idle stop solonoid would it?

 

For a carb car, dont you hsve an idle screw? I would reset the idle speed and re-adjust the timing.

 

I'll check the idle screw, but I was under the impression with a Electronically controlled carb you didn't really want to mess with the idle screw...

As for timing, i'm at 12 advanced initial (distributor unplugged), 36 actual, I believe is what the dyno guy said.

 

On my '87 EFI OBDI car, I do set the idle RPM and can set the base timing while the EST wire is disconnected. So, I assume that there should be no issue with you doing the same as long as you follow the proper instructions.

 

I'm just curious about how this is supposed to run because the idle, for the most part stays where it's supposed to but...for example.

Today I came home from work, (13 miles one way), the car was well warmed up but when I put it into park, it jumped to high idle (1300ish). put it in drive again, dropped to 650-700, back to park, normal idle (1000ish). I just wish it would stay where it's supposed to. it's been crazy ever since I put this new 350 in the car.

 

On the CC carb, it does have a throttle position sensor. It's just buried inside the carb. It's located on the driver side front; you can see the three pin connector coming out the front of the carb.

The idle stop solenoid is used to increase idle when the A/C is turned on.