I have a 93 Plymouth Grand Voyager. It back fires into the intake on accelleration, worse when the ambient temp is high. Quick test on the EEC are EGR related. eplacement of EGR did not fix the problem. I suspect the backfire is setting codes. Fuel pressues is to spec.
Any ideas?
The 3.3 V6 is very susceptible to bad spark plug wires. This usually starts happening during rain when they get wet and cross-fire, causing the backfire. Maybe high humidity would do it too. Changing the plug wires would be my first try. They're not expensive - about $25.
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Eureka, Problem found the centre of # 4 spark plug was broken. The procelan is still intact but the piece from where the wire plugs on to the centre fire point is burnrd off about 2/3 of the way down. The plugs have about 45,000 km on them. Little wonder it was hard to find.
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