Backwards firing order

[flightmech]

I picked up a 1978 postal jeep to use on a rural route. I don't think the engine is original, it is an inline 4, probably 2.5. The valve cover is stamped, American Motors 1-3-2-4, which I'm sure is the firing order. It was running when I bought it but had severe hesitation when pushing the accelerator even when hot. I didn't bother looking at the spark plug wiring before replacing the plugs,wires, rotor and cap, knowing I would be able to get them in the right sequence. However, now the jeep won't start with the correct firing order, and the only way it will start is backwards 4-2-3-1. With the same hesitation and very little power.I don't know what has been done to this engine previously. Is it possibly the distributor in 180 out? any advice?

 

[ka041a]

it wouldn't matter if the distributor was in 180 off as long as the spark plug wires are going to the cylinder that is on top dead center of the compression stroke. you could have no. 1 be at any of the four towers on the distributor cap. i would guess that you have a vacuum leak, but the first step is always to check the compression because there is no point in working on an engine that has bad compression. good luck, john

 

[carnuck]

All inline 4 cyls are 1-3-4-2 firing order (except the oddball early IH motor) If you can swap the wires around on 3 and 2 or 3 and 4 with minimal difference, then probably the headgasket is bypassing between those 2 cyls.