If you read this post on the 4th Gen forum - don't wast your time reading this...but i could certanily use some advice.

Hello everyone!!

For a few months now, i've noticed a slight hesitation during accleration. I'll shift, push the accelerator 1/2 to WOT and hold steady. The car accelerates, but not smoothly...I can't tell if it's surging, or hesitating, but either way, the acceleration is not constant. I recently (last two weeks) changed plugs and fuel filter. After the fuel filter change (this weekend), things seemed to be better, i didn't notice this problem until yesterday when things went real bad... loss of power, bad hesitation, etc. I was running low on gas (light wasn't on yet) and it was acting like it was running out of gas (no power, jerky, hesitating). I pulled into a gas station and put in 5gal.

I started driving again and got the check engine light. I checked it and saw a "Cylinder 5 missfire" and a "knock detected or circuit fault" codes. I cleared the ECU the normal way and also disconnected the battery for a while. I checked the EGR valve operation per the Haynes book, "rev engine to 2k-4k then let close the throttle and feel for the EGR shaft to move". I couldn't feel the shaft, but i could feel the diaphram. It moved slightly (maybe 1mm total) while reving up, but didn't move when closing the throttle. This doens't seem right... I tried to disconnect the vaccume tube to the EGR to test for vacumme, but it wasn't able to pull it off. So i just started the car and went for a test drive to see if the low gas caused the problem, then the ECU adjusted for the missfire and knock, but now i have gas and reset the ECU...so maybe all is well??? Nope... the care stared good, sounded smooth... I revved the engine and it seemed ok... but the more i revved it, I could tell something wasn't right. I started to drive... it threw the same codes again... Cyl 5 misfire and knock detected.

Seeing Cyl 5 both times is interresting. If it was an emission control problem, it shouldn't just be picking on cyl 5. So i swapped the plug and coil from cyl 5 with the plug and coil from cly 3. The plugs looked identical, i didn't see anything wierd on the 5 cyl plug. Started back up, drove it, no error lights, no major problem, but the hesitation/surging that was present before was still there... so somethings still not right.

That EGR thing still bugs me, and the hesitation is livable, but not right... any ideas???

Sorry it's so long, but i wanted to be through with the problem and the things I already tried.

97 Max SE
65,000 miles
JWT Pop Charger
Manual