Misfire no cel very frustrating.... please help

[thatone1320copcar]

Hi all, since buying this car ive had nothing but minor issues that have been fixed relatively easy. Now im stumped.... i have a misfire(i think). At idle its constant but at highway speeds it tremendously smooths out but its still there and the power difference is noticable. The car idles very rough. Pulled wires off coil pack as it was idling and cylinders 2 and 6 didnt change idle and as i pulled off cylinder 1 the spark jumped through the plastic in the coil pack to the bracket. Checked all injector plugs and they are all plugged in. Does not sound like there is a vacuum leak, all hoses are connected have not got around to spraying carb cleaner to verify no leaks. Car is a 97 gt and has a new fuel filter (150 miles) new plugs and wires (150 miles) new intake manifold from previous owner. Crown vic upper plenum, iacv restrictor plate, k&n fipk filter. Just swapped green coolant temp sensor with a spare i had here as the conector broke off the old one. Any help is greatly appreciated.

 

[thatone1320copcar]

Ok so update, the battery guage on the dash is bouncimg around at idle. Doesnt dip too low but it doesnt look good. And also still no check engine light but i hooked up my scanner for shits and giggles and it came back with p0401pd. How ofter do injectors go bad on these cars? Wondering if i have dead ones. Also what could cause insufficient egr flow?

 

[thatone1320copcar]

Update: took car out for a drive today to see if she acted different in the rain and had to go to the junkyard anyways. Threw a cel finally, havent had a chance to hook up my scanner. While at the junkyard found a set of almost new looking screamin demon coil packs. Grabbed them for 6$ thoughts on these coils? And will report back with cel code when i get 5 minutes free to hook up my scan tool

 

[thatone1320copcar]

Ok had some free time, it was throwing codes for too lean on banks 1 and 2 and the egr code was still there without pd after it. Sprayed the intake down with carb cleaner and it didnt raise the idle anywhere so no vacuum leaks and its weird that this happened completely put of nowhere. I also tried to check my livestream data on my scanner and it didnt show the o2's reading consistantly, the voltage was jumping around alot, reading and jumping back to 0. I have a pi manifold sitting in my garage that i havent had time to swap, not sure if now would be a good time or not...

 

[96blak54]

By all this description ^, you are on the trail.

Water in the plug holes is a big culprit, but lean codes throws that one out. Im stumped, so let me cheer you on! Be sure to report back when you find the problem.

 

[07GtS197]

It seems that this is a common problem with new edge v6's. Usually the problem is the pdfe sensor.

 

[thatone1320copcar]

Got a new ford pi intake manifold, and gaskets incase the dorman intake i had wasnt makeing a good seal, putting that on now, the autozone 2 blocks from me has a dpfe in stock so i plan on picking that up as its cheaper than injectors, i did clean mine while i had it apart. Will report back with findings

 

[thatone1320copcar]

Swapped dpfe still running the same. Still plugs 1,2, and 6 still giving issues..... screamin demon coilpacks have a bright spark from them. Way brighter than stock. 02 sensors reading voltage now.

 

[thatone1320copcar]

Bought one injector before springing for a full set, threw it on cylinder 6 to see if any change. No change with injector. Pulled sparkplug to look at, showed signs of running lean but smelled of fuel. Should have verified gap completely forgot till now. Swapped on spare spark plug wire i had, smoothed out idle slightly, returned wires back to autozone under warrenty, put new set on, back to no change in idle when pulling wires 1,2, and 6. Gonna hook up my timing light tomorrow and check timing as im running out of things to check. If timings ok im going to move to compression.... running out of ideas here... anyone?

 

[thatone1320copcar]

Found a thread on another forumn and someone was talking about similar symptoms as me and it turns out it was his iacv. Said after he swapped his plenum with a better flowing one, and his iacv went out shortly after. Not sure if that makes sense to me though. Although most of these issues have happened after i did a plenum swap with my old ported and polished crown vic plenum. I know its not gaskets because ive changed them like 5 times already

 

[thatone1320copcar]

Oh and some information that might be relevant. After plenum swap everything was amazing, it drove beautifully. Then after putting about 100 miles on it is when it started running really rough. The about 10 miles later is when ith threw the codes for lean bank 1 and 2. Not sure if thats helpful or not.

 

[96blak54]

Unplug the maf sensor, then go drive it. Drive it hard, try to feel the miss. Im thinking the maf is glitching your big problem. Take some dielectric grease to the coil pack towers. Ford design coil packs are the most trusted coil packs. Accel, msd,...you name it....Ford packs always get put back on. The dielectric grease will help contain stray arcing between the coil pack towers. Possible a coil pack has a tiny tiny tiny crack that gaps open more as it warms with the engine

 

[thatone1320copcar]

Car wont even start with maf disconnected

 

[Burninriverdiver]

Do you still have the stock upper plenum? Might be worth a shot to see if that's the culprit (highly doubt it is) and also make sure all the rubber hoses aren't cracked somewhere going to the plenum. Other than that my only advice is to make sure the plug wires are in order, I messed the order of one of my previous cars up and swore it was correct till I double checked the diagram.

 

[96blak54]

^
That makes sense!

 

[thatone1320copcar]

Ill give that a shot^^

 

[thatone1320copcar]

Sparkplug wires are in correct order. Fuel pressure is at 40psi without vacuum, connected vacuum line and it went down to 38. When giving a little gas fuel pressure dropped to 35psi. Does that seem right?

 

[96blak54]

Car wont even start with maf disconnected

Something dead wrong.

 

[thatone1320copcar]

Checked timing with timing light. It was off time at idle but as youngive it gas the timing mark lines up with the che k mark as the motor smoothes out at higher rpm

 

[Burninriverdiver]

I'd keep checking the brittle plastic vacuum lines. Also from personal experience, the dorman intake is not easily compatible with NPI heads without tons of RTV, if you've got a PI intake manifold it'll be worth the effort to swap that in.