99 expy misfire

[cole45]

i am getting stumped. i am no stranger to ford vehicles i have worked on them for years both as a hobby and as a job. i bought a 99 expy with a bad engine. swaped engines out of a 96 van. checked engine before swap so i no it ran fine. the engine swap went fine but the engine is missing. i had a p1131 o2 lean. replaced it. replaced fuel filter, cleaned maf, new air filter, replaced pcv valve assembly, new plugs auto light double platiums. attempting to reset the computer for the air fuel mixture. engine miss at idle and going down the road. it feels like a cop is bad but no codes set. ran live data on scan tool and reads no misfires present even though i can feel one. i unplugged number 1 coil while running engine didn't change. have the coils from the van's engine but not sure replacing them will solve my problem. wish it would set the cel so i know where to go. all help apperciated

 

[cole45]

well still working. i did an ohms check on all coils. found one bad for sure a spring bad in another and 1 boot torn. still a miss but not near as bad. i think someof the other boots have taken on water. might have to break down and take it to the shop and put it on the wds to find the cylinder that is missing

 

[cole45]

well hope this helps others. found my misfire. did have to hook it up to the wds. number 4 cylinder not firing. i had two problems. first i cut an o-ring installing the heater hose to the cowl. this leak enough antifreeze down over time into teh number four hole it was half full of antifreeze. next and the most important was number four coil was not being powered. how to check this. with the key on engine off take a voltage check on the power side to the coil. you can tell the side by looking at the coil. the b+ side is the power side. you should have 12 volts at this side. when you check the secdonary side you should not get any volts there. be sure to do this check before you remove the intake there is enough room. i wanted to double check myself and didn't witht ehintake off and forgot about the 3 second fuel run. i had a bad wire in the run where the plug enters the wire loom. easy fix. i spiced it back together with a waterproof butt connector with heat srink. i am always happy to help others with there vehicle not matter how strange i am sure i can find the answer.

 

[napew2009]

misfire

I had the same problem with mine after a motor swap. initially ran well until two days later, it ran like shit. I took it into shop and they found that antifreeze had seeped into ports 3/5 or was it 4/5, dunno, but they cleaned it out and ran much better since then.

 

[Quevy50]

Bad Coils

I had a similar problem with my coils on my 5.4L. Engine started misfiring with no check-engine light. Finally after a week of running and mis-firing a code appeared. It was the #2 coil.
Bought (8) coils on e-bay from Global for $80 bucks. Installed this past weekend. Truck now running great!!