euthorus

Me and a friend did a simple plug and wire change for 1995 Ford Explorer with a 4.0L SOHC V6 engine. He convinced me that the Autolite AP105's I bought came pre-gapped for my Explorer so I didnt gap them. After the swap the car is having a hard time idling. Sounds very much like its misfiring so I checked and double checked the wire connections and everything seems fine. Could the lack of gapping the plugs do this ?

sohc_mshue

do you have the firing order correct?

euthorus

Do you mean did I cap the wrong coil ?

Fabrik8

Pardon my ignorance about Explorers (ten foot pole, all that stuff) but are those engines coil pack or distributed coil? If they're coil pack, you may have pulled a wire loose or broken a wire where it meets the connector. It's usually hard to mix up the plugs on coilpack systems, so I'm assuming that's not a problem. But yes, you should probably yank at least one plug and check the gap.

If it's a remote coil setup with high voltage leads, you've probably swapped two of the plug wires, or broken a plug wire at one of the connections. Cheap wires are known for doing stuff like that.


It's really easy to pull a plug out, why not just check the gap and rule that out?

euthorus

Man this is really kicking my butt. Replaced the plugs again with a new set now using the Motorcraft ones. Checked the firing order, checked for vacuum leaks, using brand new BWD (Pep Boys) wires, gapped the plugs all per spec and I am out of ideas. The engine runs like crap - had a friend hold the accelerator down to keep an even 2000RPM and it kept on pulsing up and down on its own about 200RPM. The coil pack seems fine too - all plugs are now firing.

Any Ford specialized techs around ?

Cliff notes: running fine but old plugs, replaced plugs and wires, engine runs like crap now.

BradEK

fuck it...put the old plugs back in haha

Enigma

No spark plug will have the right gap for your particular vehicle.

What were the wire/plug combo used before?

What does Ford say should be used in the vehicle, platinum/double platinum/fine-wire?

CEL?

Did you test the coil?

Did you test the wires?

E

euthorus

LOL

No CEL, seems to be the worst when idling as I still get a decent throttle response when moving. Tested the coil the redneck way by pulling the caps off and watching the light show. The wires are brand new and appropriate gage but I did not test them. The gap was correct per spec on these new plugs which are Motorcraft fine-wire. Going to have to wait till I get home to see the exact combo used b4.

subhunter

I'm not too familar with the 4.0L but does it have an IAC? That's what this sounds like to me

euthorus

Replaced the IAC and it didnt help...then noticed that the EGR valve tiny straw lines got reversed when they were unplugged to reach the spark plug socket....

Exploder runs like butter now.

Thanks all for suggestions.