sailbatnite

My firebird has to be jump started to get it going. The starter, alternator, and battery (tested), ignition module are all good. I am getting two codes on it.

Code 35, which is Idle air control (IAC) system problem-can not set desired RPM

Code 43, Electronic spark timing (EST) circuit - low voltage detected. or Electronic spark control circuit problems.

I had a shop look at it, after replacing the starter 5 different times, because they thought each one was bad. SMH and then they said the ground to the starter was dirty and loose so they cleaned it up and tightened it, and said it started ok. It did after a few days then went back to not being able to start. Sometimes the battery does show it is low, but there are times when i turn the key and I am getting full power and it does not start.
I am not sure what else to do with it. today i was working on it and found one of the spark plug wires on the ignition module just placed on top of it, i pushed it down until it clicked in, i thought that would fix it, (nope) even after having the battery on a charger, the power meter on dashboard showed no power at all.

W.E.G.

Disconnect your negative battery terminal.

Make sure connector on brownish-colored EST wire that runs along top of firewall near your A/C is not damaged or disconnected.

Reach up under your passenger side dash, and fetch the ECM out from under there.

Unplug the ECM from the harness.
Inspect connectors for corrosion.

Pull the two PROM chips out.
Inspect connectors for corrosion.

Put the PROM chips back in, and reconnnect the ECM harness.

Reconnect negative battery terminal.

Test to see if that "fixed" anything.
Report results here.

Don't go to that shop any more for motor/drivability issues.
They clearly have NO IDEA what they are doing with a third-gen car.

OrangeBird

iTrader: (1)

Troubleshoot the actual symptoms first .....

You say the voltmeter on the dash reads nothing ? These aren't the most accurate gauges ever installed in a car (understatement) but it should at least show , , something . The fact that you have at least one , and possibly more electrical devices malfunctioning when it won't start is a clear indication of a bad connection somewhere in the wiring or other malfunctioned component , and no I don't believe the bad connection resides in the ECM (since it and the voltmeter share pretty much nothing in common except maybe the battery and the ignition switch)

PS , a better description of the won't start condition would be most helpful , does the starter crank the engine but it never actually fires up ? Does the starter fail to turn the engine ? If the starter does crank the engine , is it cranking too slow (and hence needing the jump ?) . It's these little details that can help pinpoint the problem by eliminating things that can't possibly be the problem (As in , if the starter tries to engage but won't even turn the crankshaft you really don't need to be pulling ECM chips & so fourth , since they physically CAN'T keep the starter from turning the crankshaft)

maroe624

Install a push start and call it a day.