1987 350 tpi; mods that might cause this problem or i'm unsure of: AFPR set at 48psi, coolant fan control switch is disconnected (and not grounded).

has new IAC, TPS, new ECM and a whole bunch of other parts.

the car is giving me a code 45(rich condition) and the idle will not drop below 2000 rpm. I installed a new ECM and reset the IAC. when the IAC is unplugged and i'm setting the base idle the car is not firing on a couple cylinder under 700rpm, like it's getting too much fuel. once I get done setting the base idle and plug in the idle air control it jumps to 2000 rpm and doesn't lower, even when the engine is at 220*

any thoughts?

 

Vacuum to fuel regulator leak, faulty regulator?
If it's running rich plugs are probably fouled by now and may not fire at low rpm.
Check ECM temp sensor - can fail near the cold range without setting a code causing the ECM to think it needs alot of fuel to run.

Even new ignition parts can be faulty. I bought a set of performance wires that were too low in resistance, engine stumbled like crazy. What? resistance to low, yes, too low ( I thought that was a good thing, but in my case it wasn't.)

Did you check the base timing and disconnect the "Set Timing Connector" before calibrating the IAC?

 

would the ECM temp sensor be the one in the passenger side's head or the front of the TPI? i'll test the resistance of the new IAC. Yes, base timing is set at 10*BTDC. no vacuum leak to regulator, regulator was working fine before I replaced the bad ECM. bad ECM was causing a "limp like mode" after 5 minutes of driving but ran fine before that.
I'll try disconnecting the 9th injector while setting base idle to see if that cures the misfiring.
So it does make sense that possibly a bad coolant temp sensor is causing the ECM to think it's still cold? thus extra fuel and high RPM?

 

bump?

 

Possible? Yes. It happened to me (ECM thought it was 20°F.)
Symptom would be gray smoke, rough idle, no power, may even overheat.

 

I replaced the sensor since I had to take it out of its tight location to test it anyway.
but the sensor wasn't the problem.

 

I know, old thread. Did you get this resolved? I believe base timing should be 6-BTDC. If you got this figured out, how did you do it? I'm having a similar issue.

 

I had the "EGR switch" wire plugged into the O2 sensor. They have the same weather pack connectors so I thought they went together lol there was other issues too but this was the main one