Changed plugs and wires, now surging!!!! | Ford Explorer Forums - Serious Explorations

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Changed plugs and wires, now surging!!!!


Well-Known Member
July 12, 2003
Reaction score
City, State
Albuquerque, New Mexico
Year, Model & Trim Level
1993 xlt
I just got done replacing plugs and wires(motorcraft wires and plugs) and now the ex is ideling weird. It is jumping from 500-700 RPM speratically. The wires are in the proper order according to the repair manual. Any ideas on this?

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Did you unplug the negative for 15 minutes?

no I didnt disconnect the battery cable. Do you have to do that to reset the computer after plugs and wires? I didnt realize that. I will try that here in a while when I get off work. Thanks

Now that you got good fire, it may have exposed anither weakness.

Good luck in resolving the problem.....

Ok today I checked for any vacuum lines I may have knocked off or any other connectors and couldnt find anything that had come disconnected. Also disconnected negative cable for 15 minutes and reconnected and that did nothing at all. Anyone have any ideas? It runs fine when accelerating and anytime that it is not at idle, but when stopped at a light or something like that it kinda surges and feels almost like it might die but not quite. It doesnt seem to lack power or anything like that either. No evidence of it backfiring either. Not sure what the issue is. I guess its telling me "if it aint broke dont fix it". I was just doing normal maintenance but I guess the ol ex like the old parts better. Any advice or ideas would be greatly appreciated. Thanks in advance

I had the same symptoms when my DPFE went bad.

Check your ignition wires again and make sure that if they cross each other they are at a 90deg angle. It's best not to have them cross at all, but sometimes it can't be avoided. Also make sure all of the boots are seated good. Not sure if it'll help but it's something to look for. I've found when something like this crops up it's usually a result of something that was done, eg. something got disconnected, or wasn't replaced exactly quite right. Also, don't forget that you have an idle compensator that kicks in whenever the a/c compressor is running. Does the rpm increase coincide with the a/c compressor?


Ok now I have more of an issue. Now I have backfiring at a low rate of speed. I have triple checked the location and connection of all wires and everything seems ok. Is it possible that I got a bad wire or something? The whole thing is that before I changed the plugs and wires my ex ran PERFECTLY. I have no idea what to do as this is my daily driver and have either work or school everyday of the week so I have to be able to drive it.

TPS or IAC valve.

Also, might seem like a dumb question but, did you gap the plugs properly?

Kinda sounds like a bad plug. Did you crack the porcylne(sp) on any of them? I did that once and had the same problem.

Most likely a bad wire, bad connection or the porcelain is cracked on a plug

The plugs are gapped properly. Im pretty sure I didnt crack any plugs putting them in. How do you check for bad wires? I bought the motorcraft ones hoping I would be ok. If I did get a bad wire what kind should I go with?

If you've still got the old wires you can put them back in and see if it fixes the problem. The motorcraft wires should be alright. I bought the bosch, but only because it wasn't that much more compared to the others. I haven't had any problems with them, in fact they seemed to make my explorer idle better and it has a little better response than before.

I do not have the old wires as I threw them away because I didnt know I needed them. I will remember to keep that kind of stuff from now on though. I get off work here in a few minutes nad me and my dad are going to see if we can figure out whats wrong. Hopefully we can figure out whats wrong because Im tired of hearing *BOOM* when it backfires every once in a while.

here is just a thought, make sure your wires are correct. By this i mean i used the #1 where the #3 wire should have been and vise-ver-sa. This led one wire was longer then it should and the other too short.

just a thought, good luck