P 0302 and I dont know what to do next.
#1
P 0302 and I dont know what to do next.
Hello Techs I have a 1997 ranger xlt 4.0 4x4 v6 Red and I love my truck. It was neglected before I got it and I have put a lot of work into her. But now I am down to the last trouble code that recently popped up. P 0302. this happened after I put in new coil pack and plug wires and plugs, #2 twice. She runs good on the highway. Just got back from 600 mile round trip but the whole time when at idle she chugs and runs rough. on the highway I can feel it missing but ran good otherwise. got 15.6 mph. which is average for her. 5 speed trans is awesome in 4x4. well 4 with OD. Any ways I have pulled my hair out trying to figure this one out. I just replaced evap selonoid, purge valve for the P 1443 code. She has a new IAT and EGR works. However not so sure about the DPFE it is 27 years old. Also it took two years to figure out the P171 and P 174 codes, turned out to be the fuel fill hose had a gash in it right above the tank clamp. So while down there I replaced the fuel pump. Fuel filter is less than a year old. The injector test at 13 ohms, and I can hear it tapping away with my thesiscope. Even put two bottle of injector cleaner in it on my trip. The plug is new and looks new still. Check it two days ago. switched plug wires just to see if it was that and no change. Compression checked it and it came back at 155. So this is why I am bald now. Air cleaner is new. Two years ago I replaced the intake gaskets, valve cover gaskets, fuel rail gasket, all of them. Vacumm lines are new. I thought I had it made with the fuel fill hose and my troubles were over but thats when the P 0302 started to mess with me. Is it gremlins or what?
#2
#3
#4
RF Veteran
iTrader: (1)
Ford uses a Waste Spark system, first spark system ever used on gasoline engines in the 1890's, uses crank timing not cam timing like a distributor
The coil pack on a V6 just has 3 coils inside, not 6
Each coil sparks 2 cylinders at the same time, only 1 spark is used the other is "wasted", hence the name "Waste Spark System"
The Matched Pairs are 1/5, 2/6 and 3/4
You can see that on the spark plug wiring on coil pack
3 4
2 6
1 5
front
3/4, 2/6, 1/5
Try swapping around 2 and 6 wires at the coil pack to see if misfire changes to P0306
3 4
6 2
1 5
front
If it stays as P0302 then problem is specific to cylinder 2
If it changes to P0306 then swap back in old coil pack
Fuel
Unplug Coil packs 4 wire connector, you want a No Start
Crank engine over 2 or 3 times
Pull out spark plugs in cylinders 1 and 2
Compare the tips
Both should be equally WET with fuel, if so then fuel is not the issue
If 2 is dry then you have a clogged injector
Just as a heads up, misfire codes are usually accurate but its usually not 100% acurate
If you get a chance remove all spark plugs and test compression on all 6, write down results
It could be misfire is not #2 at all
The coil pack on a V6 just has 3 coils inside, not 6
Each coil sparks 2 cylinders at the same time, only 1 spark is used the other is "wasted", hence the name "Waste Spark System"
The Matched Pairs are 1/5, 2/6 and 3/4
You can see that on the spark plug wiring on coil pack
3 4
2 6
1 5
front
3/4, 2/6, 1/5
Try swapping around 2 and 6 wires at the coil pack to see if misfire changes to P0306
3 4
6 2
1 5
front
If it stays as P0302 then problem is specific to cylinder 2
If it changes to P0306 then swap back in old coil pack
Fuel
Unplug Coil packs 4 wire connector, you want a No Start
Crank engine over 2 or 3 times
Pull out spark plugs in cylinders 1 and 2
Compare the tips
Both should be equally WET with fuel, if so then fuel is not the issue
If 2 is dry then you have a clogged injector
Just as a heads up, misfire codes are usually accurate but its usually not 100% acurate
If you get a chance remove all spark plugs and test compression on all 6, write down results
It could be misfire is not #2 at all
Last edited by RonD; 03-06-2023 at 11:16 AM.
The following users liked this post:
DILLARD000 (03-06-2023)
#5
The "technology" in my old 2001 is older than I thought.
Just kidding; think you meant Ford EDIS was first used in the 1980's.
Though no doubt Wheels were invented+used much earlier!
Last edited by DILLARD000; 03-07-2023 at 12:25 AM.
The following users liked this post:
RonD (03-06-2023)
#6
Ford uses a Waste Spark system, first spark system ever used on gasoline engines in the 1890's, uses crank timing not cam timing like a distributor
The coil pack on a V6 just has 3 coils inside, not 6
Each coil sparks 2 cylinders at the same time, only 1 spark is used the other is "wasted", hence the name "Waste Spark System"
The Matched Pairs are 1/5, 2/6 and 3/4
You can see that on the spark plug wiring on coil pack
3 4
2 6
1 5
front
3/4, 2/6, 1/5
Try swapping around 2 and 6 wires at the coil pack to see if misfire changes to P0306
3 4
6 2
1 5
front
If it stays as P0302 then problem is specific to cylinder 2
If it changes to P0306 then swap back in old coil pack
Fuel
Unplug Coil packs 4 wire connector, you want a No Start
Crank engine over 2 or 3 times
Pull out spark plugs in cylinders 1 and 2
Compare the tips
Both should be equally WET with fuel, if so then fuel is not the issue
If 2 is dry then you have a clogged injector
Just as a heads up, misfire codes are usually accurate but its usually not 100% acurate
If you get a chance remove all spark plugs and test compression on all 6, write down results
It could be misfire is not #2 at all
The coil pack on a V6 just has 3 coils inside, not 6
Each coil sparks 2 cylinders at the same time, only 1 spark is used the other is "wasted", hence the name "Waste Spark System"
The Matched Pairs are 1/5, 2/6 and 3/4
You can see that on the spark plug wiring on coil pack
3 4
2 6
1 5
front
3/4, 2/6, 1/5
Try swapping around 2 and 6 wires at the coil pack to see if misfire changes to P0306
3 4
6 2
1 5
front
If it stays as P0302 then problem is specific to cylinder 2
If it changes to P0306 then swap back in old coil pack
Fuel
Unplug Coil packs 4 wire connector, you want a No Start
Crank engine over 2 or 3 times
Pull out spark plugs in cylinders 1 and 2
Compare the tips
Both should be equally WET with fuel, if so then fuel is not the issue
If 2 is dry then you have a clogged injector
Just as a heads up, misfire codes are usually accurate but its usually not 100% acurate
If you get a chance remove all spark plugs and test compression on all 6, write down results
It could be misfire is not #2 at all
thanks i will let you know how it turns over, lol. over and out.
#7
RF Veteran
iTrader: (1)
Thread
Thread Starter
Forum
Replies
Last Post
dunerider09
4.0L OHV & SOHC V6 Tech
10
10-29-2011 08:32 PM