Alternator
New spark plugs do not always come pre-gapped. It is always wise to check the gap before installing. The routing of the leads have to be in the same order as they were removed, otherwise cross-firing can occur. Ensure the leads are installed at the distributor in the correct firing order.
Make sure the firing order is correct that you didn't mix up the leads when changing plugs.
it sounds like you need a new coil pack Or you could have two of the plug leads reversed. I'd check and make sure I have voltage at all 4 plugs before I bought a coil pack.
When you track leads you can focus your marketing in the area where most of your leads come from. If you are focusing in your correct area, your returns will be better.
mg zr firing order
Many V6 engines have been based on V8 designs. One characteristic of these engines is a notorious odd-firing behavior. Purpose-built V6 engines use one crankpin per cylinder for a smooth ignition 120 degree ignition pattern. Most V8 engines share a common crankpin between opposite cylinders in each bank. That is, the crankshaft has just four pins for eight cylinders, and a cylinder fires every 90 degree for smooth operation. When two cylinders are "removed" for a V6 variant, the firing order becomes uneven. One 90 degree ignition is removed, so the engine fires at 90 degree, 90 degree, 90 degree, and skips one 90 degree. This leads to a rough idle and increased stress on the engine mounts and chassis.
what is the firing order & leads for a landrover discovery 1991 3.5 v8i duel fuel
If its a CA20 engine (which it probably is if it has 8 leads) the order is 1 3 4 2
May have failed coil pack, there are 3 coil packs and 3 leads, 1 coil pack fire 2 cylinders in wasted spark. Isolate the failing cylinder and test the input voltage and signal to coil using a led test light or noid light. If signal is present- replace the coil pack If no signal possible crank/cam sensor issue or ecu
Firing order is 1-3-4-2.
1 3 4 2 is firing order
Suggest blown head gasket with coolant leaking into one cylinder. Check colour of oil. If emulsified (mucky brown) then definite leak. Also, remove HT leads one by one to identify whether all cylinders are firing. If one is not firing, remove spark plug, then remove all other HT leads and turn engine over. You may find that coolant shoots out of the cylinder, indicating leak into that cylinder.