Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Okay guys/girls this one is messing with me. Under a slight load this will start misfiring. #4 seems to be a secondary misfire it will make the engine light come on and flash. but it had a plug in with wires melted and they had twist caps on it with a new plug. we stripped back the wires and put the plug on properly but it still misfires. it would turn in to a dead miss. so i check the coil while it was a dead miss and the coil wasnt firing. the other 2 misses only miss every now and then. But we managed to get it to misfire and it looked like the coil was firing fine. the long term fuel trim is at 20 on the freeze frame but most the time looking at it, its at 7 ish. i dont understand why it would be adding fuel and cutting off that #4 cylinder. im fixing to start testing injectors but any help would be appreciated.
3.5 Ecoboost? Has anyone put plugs in it yet? If they did, were they Motorcraft?
Not trying to be a parts stickler, but I've found non-Motorcraft plugs come out of the box with the wrong gap. No one checks because, well, we're told not to gap platinum/iridium plugs.
Yes there was NGK plugs in it and we changed them out to autolight. we have swopped plugs from cylinder to cylinder. we found that the wire on #4 had no connection to the PCM so we checked the pcm side for signal and it had some. we ran new wire and #4 was firing for a min now the signal for #4 and #3 are weak on the scope. but it is trying to send signal and all other cylinders are firing now just #3 and #4.
