Chevy s10 ignition problems / trouble codes

ChrisTruck
Thu, 13 Jun 2024 14:57:59 +0000
Maintenance/Repairs

95 chevy s10 4.3 TBI 293k miles. I’ve been getting a CEL at startup for a while, it was just for a minute when I started the truck, then would go off. PO320 code and sometimes a PO328 code also. My scanner calls both the codes electronic spark control circuit fault and ESC open circuit. Looking up the codes online, they relate to knock sensor and crankshaft position sensor. The truck doesn’t have a crankshaft sensor that I’m aware of.

I swapped the cap, rotor, ICM and ignition coil with no difference. I spliced new connectors for the ICM and now the PO320 stays on all the time and it runs rough. I didn’t mix up any wires. I’ve also had a malfunctioning temp. gauge which started around the same time. I suspect it’s a wiring problem, but don’t know. The truck has 2 knock sensors, one has been replaced a while back and the other is under the distributor at the rear of the engine and is very hard to access. I’m not good with the electrical diagnostics, I’m hoping someone could steer me in the right direction. Thanks

8 posts - 5 participants