Cranks Won't Start After Coolant Spill - Fouled Plugs and Bad Wires

Electricalintermediate✓ OP Confirmed

Problem

1989 non-turbo Supra (7MGE, automatic) cranks but will not start after coolant accidentally spilled over the engine when a coolant line on the throttle body was mistakenly pulled off thinking it was a vacuum line. Before the spill, the car ran and started fine.

Engine cranks but will not startEngine briefly catches if given gas during cranking but immediately diesSmall puffs of white smoke visible around the throttle body during cranking attemptsPrior to no-start: rough idle around 500 RPM, engine shaking in drive and reverseDiagnostic codes 25 (lean air/fuel ratio), 41 and 51 (TPS related)

Root Cause

Coolant from the spill entered the spark plug wells and soaked the spark plugs, preventing proper ignition. The existing spark plug wires were also deteriorated and allowing both water and oil (from leaking valve cover gaskets) to reach the spark plugs, compounding the fouling.

Confidence

High confidence — Original poster confirmed this resolved the issue

View Original Thread →Posted July 2023 on SupraForums.com