Moe

Well so far I've replaced:
Fuel pump, Fuel filter, Fuel Pressure Regulator, Throttle Position sensor, Hall sending unit, Dist. Cap and Rotor. Battery.

I still have this annoying low idle when she warms up, when cold, she idles at 1000 rpm, relativly smooth. When she starts to warm the idle speed goes to 900, then every 3 or 4 seconds she drops to 800(est.) for a second or so, then back to 900 and so on.

Would it be OK to turn the screw under the throttle lever to set the idle at 1000, till I get some more time to fool with this problem?

Thanks

Moe

Oh yea, when I got the Hall sender unit in, it made no difference. It runs the same as if it were unplugged.

I think my next move is to check the DME plug. ? ! ?

Kevin Baker

Moe, have you checked the idle air control valve? It sounds to me like the "cold start" circut is working properly. IIRC the idle air control valve would cause this type of problem when the engine is hot because when cold, the DME will open the IAC to lean the mixture, as well as decrease injector pulse lenght. When the temp sender tells the DME that the engine is up to operating temp, it would allow the IAC to close, maybe yours is not functioning properly.

Moe

Just checked vacuum....I get "0" vacuum at idle from the T-Body.
When I rev her up, I get plenty of vacuum but it drops off to nothing as soon as the RPMS drop.

When I pull a vacuum on everything (engine off) but the T-Body, she holds a vacuum.

Is that the way it's supposed to work?

I allways thought you would get some vacuum at idle.