I finally got my L back from HB Ford with the paint job it should have had from the factory...only took a month and three trips to the dealer Anyways, I installed a JL Diablo Chip in her last week. Drove like a bat out of hell. Started noticing a rough idle occasionally towards a quarter of a tank of gas. Rough idle began getting worse and I began feeling a hesitation a cruising speeds. After filling up with s*** California 91 octane gas the stumbles and rough idle began getting worse. Drove home from the dealer tonight and removed the chip and drove around the block without the chip and it was even worse than before. Also sounds different...blower whine is cutting on and off...rough idle and hesitation from off idle. Got dark, so I covered the truck and was gonna remove the pcm and check all connections under the hood.

Anybody else had any problems resembling this...rough idle...hesitaion, or anything I described??? Help me!!!

 

If it stumbles with chip removed it is likey a Sparkplug/coilpack or a fuelpump issue

Doug

 

I have had nothing but problems with this truck since I bought it. This is very frustrating. I will check out the plugs and coil packs tomorrow and will once again have to drop off the truck at the dealer. Truck was driven off the lot on September 6 and this will be the 4th trip back to dealer.

 

Check the rear passenger side coil pack for even the slightest amount of antifreeze. There's a heaterhose clamp right above it that's notorious for leaking and shorting out the #4 coil pack.

 

If it's only doing it when you are low on fuel I bet the clamps have let go on your fuel pump. In tank fuel pump.

 

I currently have 3/4 of a tank of Cali 91 gas. Happens at idle and on acceleration and cruising. I am going to check connections at pcm as well as coil packs and plugs. I really don't want to have to take it the dealer again!!!

 

had, what sounds like same problem.. when it was raining and very wet out drove through some puddles, and when started to dry out truck had a rough idle and when i hit the gas would stumble and hesitate badly, even at a cruising speed of 45 50 you could feel a lobing and stumble...well pulled in the garage pulled all coil packs, used a compressor to dry the plug valleys, checked the continuity of all packs with a volt meter, looked everything over all seemed dry, on the outside, and still had the problem, made appointment with dealer for two days from then, the day of the appointment started up to go to work and all was fine, no problem at all. also through the time of the problem gas mileage went to 10 miles per compared to the 13 14 i usually get also pulling the chip did not help...checked all the previous posts of this problem and most likely candidate was a coil pack, though i havent been able to confirm since it only did this one other time only for a short while, again when it was wet out....

jim

 

Thanks for everybody's input. Took the truck to dealer and they put it on a scanner and had the #4 cylinder showing a miss. Took my loaner and have yet to get a proper diagnosis...guessing the plug and or coil pack. Also asked to have all plugs checked and retorqued. Thanks again!!!

 

 

Just picked up the L. Had "#2 & #4 plugs missing under most conditions". They replaced both plugs and it seems to be running fine now. I asked to inspect the plugs myself and they seemed fine to me. I asked to speak to the tech and he said they seemed fine as well, but replacing them solved the problem. I only hope that this will be the last time for a while at least to visit the dealer. Seems everybody there knows me by first name now that I have been there so many times this month!!!