Another rough idle? with a twist!

[rtslave]

I have been through all the threads so I'll make this as short as possible.
1997, 4x4, 145000 miles 4.6l
Wife was driving car CEL started flashing and car started running rough. changed spark plugs (bosch), air filter, fuel filter, pcv. Car ran fine for about 30 miles and the same thing CEL flashing car running rough. Was told that Bosch plugs are garbage three of the plugs were trashed, put in autolights no difference. Replaced EGR, Idle air, plug wires. When I replaced Idel air I disconnected the battery, when all that was replaced started the car, still runs rough and CEL won't come on. Then I replaced both coils and plugs again to motorcraft and triple checked the plug/wire configuration. Now the car still idels rough and has major hesitation at acceleration, once it gets going it seems to run better along as its at a higher rpm. As a side note I have had the car 9 years and for 8.5 years the CEL has been on, always thought it had something to do with the gas tank beacuse in the summer time there would be a whistleing sound come from the area by the tank and if you popped the gas cap it would go away. So with that all said any advise? Sorry for the poor spelling

 

[Thunder]

Sounds all to familiar...

Did you pull the codes at all and see what the CEL was reporting as a problem? I 've had two coil packs dumped out on me when I bought my truck. Scanned it, and no codes or anything at first. Thought it may have been an injector so I drove it for a while to see if it would clear up at all, and finally it popped a few CEL's. #2 and #8 coils were bad on mine to start, I changed them and their respective plugs and all was fine. I got another drop yesterday after a few thousand miles of use, and now #4 is dead. I'm over the 200K point right now so I guess some of this is to be expected...

Check your codes and see what your looking at. I'd pull the coil from whatever cylinder is showing misfired and put it on another to see if the problem follows. At least at that point you know if you've got a coil problem or injector problem... or something else for that matter. Either way you should start narrowing down the area your looking in. Autozone's got the coils for 60.00 or so, and all the one's I've been to stock the part.

Hope you get it figured out.

 

[rtslave]

Well with the two coil packs already changed along with the plugs, wires and all the other stuff and no CEL I'm stumped.
I also listened to the injectors with a stethascope and they were all clicking away.

 

[JUST4FUN]

autotzone will read the codes too
Stop throwing parts at it with all the money
you put in to it you could of had someone fix it right

 

[ELVATO]

Yea, autozone (and I believe advanced auto parts) reads your code for free.

In the case of my Expedition, gasoline seems to sometimes splatter on the gas cap which then makes the CEL come on. Right now it's off cuz I've had the ECU reflashed and stuff.

But yea, take it Autozone.

 

[lakmflx]

How high/low is it idling? If the throttle is out of adjustment it will trigger the CEL and that will also cause hesitation on acceleration. To adjust the throttle ther's a screw on the throttle body. When the setting of the screw if within limits (about 700-900 rpms the CEL will turn off and it should be smooth again. If not then you have a different problem. Whats your idle speed at now?