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NEED HELP Engine Misfire on 2000 Ranger 5.0L V8


Rangstang

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ADDED A COMPLETE UPDATE ON PAGE 2 SO NO ONE NEEDS TO READ EVERYTHING STEP BY STEP.

I've done 3 Ranger v8 swaps over the last 6 years prior to this one with no issues, but this one is proving challenging. Although, this is the first time I've used the long block from a Mustang instead of an Explorer. Specs when first fired listed below:

5.0L engine from 95 Mustang GT 5.0L - not rebuilt, only replaced all gaskets and seals
Upper/lower intake, throttle body, injectors (new o-rings), and fuel rail from 2000 Explorer
Exhaust manifolds are new castings from 65 Mustang with 289 V8
DPFE sensor from 2000 Explorer
PCM, PCM harness, and transmission harness from 2000 Explorer
MAF sensor from 2000 Explorer
IAC and TPS from 2000 Explorer
Coil packs from 2000 Explorer
O2 sensors from 1999 Explorer
NEW Autolite Platinum spark plugs gapped to .054" and BWD spark plug wires

No EGR on this due to the fact that I'm using the early exhaust manifolds, so there's no bung to run the EGR pipe. I've fooled the DPFE into thinking the EGR is present and the EGR remains in place, just with no vacuum line connected to the nipple and the bottom is plugged with a fitting.

Initially, I got a P0171 code, so I swapped out the O2s from the 99 set to the 2000 Explorer set I'm currently using. Cleared the code, drove it 12 miles. I then idled it for about 30 minutes another day. The next day, I pulled the plugs and found that cylinder 3 was ever so slightly tanned on the white insulating portion surrounding the electrode. All others were white like new. I bought a new plug and installed it in cylinder 3. I used a spark tester to verify that all cylinders are getting spark. Due to the fact that my primary wiring's connector on the LH coil pack that feeds cylinder 3 was cracked, I swapped it out with a spare that I had from another 5.0L Explorer motor.

I then removed the plenum and all injectors. I applied +12V to each injector individually and sprayed carb cleaner through them to verify that they were functioning and all of them had the 4 stream spray pattern. Replaced the injectors and checked resistance at the PCM connector through the harness to verify a complete circuit on all 8.

I then performed a dry, cold compression test on the engine and got 118 to 125PSI across all cylinders. Seems low, but I think it's because it's cold and dry. No one cylinder stood out. While doing that, cylinder 7's terminal came off at the plug. I bought a new set of Duraspark Gold wires and installed them yesterday.

I then read online that there have been a few cases of low alternator voltage causing misfires, but usually throwing a code for bad cam position sensor (which I didn't have). Just in case, I removed my alternator and had Autozone test it today and it put out +15.08V.

I'm at a loss at this point. I figured I'd buy a pair of coil packs just in case and see if that fixes it, but other than that, I can't imagine what it could be. Any help will be greatly appreciated!
 
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Jbrown1238

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I would change out all the plugs for another new set. I have been getting brand new bad plugs a lot lately. This is going to be the easiest thing to try first.
 

Rangstang

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I would change out all the plugs for another new set. I have been getting brand new bad plugs a lot lately. This is going to be the easiest thing to try first.
You think it's worth replacing the coil packs?
 

Jbrown1238

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You think it's worth replacing the coil packs?
I would do one thing at a time. Start with the plugs, then the coil packs, etc.
 

chvlfrk

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>>>

I've done 3 Ranger v8 swaps over the last 6 years prior to this one with no issues, but this one is proving challenging. Although, this is the first time I've used the long block from a Mustang instead of an Explorer. Specs when first fired listed below:

5.0L engine from 95 Mustang GT 5.0L - not rebuilt, only replaced all gaskets and seals
Upper/lower intake, throttle body, injectors (new o-rings), and fuel rail from 2000 Explorer
Exhaust manifolds are new castings from 65 Mustang with 289 V8
DPFE sensor from 2000 Explorer
PCM, PCM harness, and transmission harness from 2000 Explorer
MAF sensor from 2000 Explorer
IAC and TPS from 2000 Explorer
Coil packs from 2000 Explorer
O2 sensors from 1999 Explorer
NEW Autolite Platinum spark plugs gapped to .054" and BWD spark plug wires

No EGR on this due to the fact that I'm using the early exhaust manifolds, so there's no bung to run the EGR pipe. I've fooled the DPFE into thinking the EGR is present and the EGR remains in place, just with no vacuum line connected to the nipple and the bottom is plugged with a fitting.

Initially, I got a P0171 code, so I swapped out the O2s from the 99 set to the 2000 Explorer set I'm currently using. Cleared the code, drove it 12 miles. I then idled it for about 30 minutes another day. The next day, I pulled the plugs and found that cylinder 3 was ever so slightly tanned on the white insulating portion surrounding the electrode. All others were white like new. I bought a new plug and installed it in cylinder 3. I used a spark tester to verify that all cylinders are getting spark. Due to the fact that my primary wiring's connector on the LH coil pack that feeds cylinder 3 was cracked, I swapped it out with a spare that I had from another 5.0L Explorer motor.

I then removed the plenum and all injectors. I applied +12V to each injector individually and sprayed carb cleaner through them to verify that they were functioning and all of them had the 4 stream spray pattern. Replaced the injectors and checked resistance at the PCM connector through the harness to verify a complete circuit on all 8.

I then performed a dry, cold compression test on the engine and got 118 to 125PSI across all cylinders. Seems low, but I think it's because it's cold and dry. No one cylinder stood out. While doing that, cylinder 7's terminal came off at the plug. I bought a new set of Duraspark Gold wires and installed them yesterday.

I then read online that there have been a few cases of low alternator voltage causing misfires, but usually throwing a code for bad cam position sensor (which I didn't have). Just in case, I removed my alternator and had Autozone test it today and it put out +15.08V.

I'm at a loss at this point. I figured I'd buy a pair of coil packs just in case and see if that fixes it, but other than that, I can't imagine what it could be. Any help will be greatly appreciated!
================
Other than the long block you mention, have you used these mixed up parts on previous builds wthout any trouble?

What heads are you runnin, the Mustang or Explorer GT40P's?

I won't run anything but Motorcraft stuff in mine and will NEVER run anything electronic from Auto Zone or O'Reilly's.....learned that the HARD WAY a while back!

Just few things I can think of at the moment.....
 

Rangstang

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================
Other than the long block you mention, have you used these mixed up parts on previous builds wthout any trouble?

What heads are you runnin, the Mustang or Explorer GT40P's?
No, never used different years of stuff before because I've always had a 99-01 Explorer donor at my disposal. This time I bought a 98 Explorer donor, but since I had 99 and 2000 Explorer harnesses, PCM, O2s, etc., I just used all of the accessory brackets, motor mount plates, upper/lower intake from the donor. Even the injectors and fuel rail were not from the donor.

No, I've never used the E7 heads in one of these combinations before. I've always used 100% Explorer stuff until this build. Reason I decided against the Expo motor is it had 250K and the last Expo motor I rebuilt had 2 cracked heads. I had a spare pair that I attempted to use for cores, but one of them was cracked too. Told me that the GT40P heads are prone to cracking, so I opted for the E7 for now and figured I'd use GT40s down the road with the same plug angle.
 

Rangstang

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================
I won't run anything but Motorcraft stuff in mine and will NEVER run anything electronic from Auto Zone or O'Reilly's.....learned that the HARD WAY a while back!
The plug wires I bought via Rock Auto and they didn't last. The fact that nothing changed when I replaced them likely indicates that it wasn't the problem anyhow.
 

ick

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I've done 3 Ranger v8 swaps over the last 6 years prior to this one with no issues, but this one is proving challenging. Although, this is the first time I've used the long block from a Mustang instead of an Explorer. Specs when first fired listed below:

5.0L engine from 95 Mustang GT 5.0L - not rebuilt, only replaced all gaskets and seals
Upper/lower intake, throttle body, injectors (new o-rings), and fuel rail from 2000 Explorer
Exhaust manifolds are new castings from 65 Mustang with 289 V8
DPFE sensor from 2000 Explorer
PCM, PCM harness, and transmission harness from 2000 Explorer
MAF sensor from 2000 Explorer
IAC and TPS from 2000 Explorer
Coil packs from 2000 Explorer
O2 sensors from 1999 Explorer
NEW Autolite Platinum spark plugs gapped to .054" and BWD spark plug wires

No EGR on this due to the fact that I'm using the early exhaust manifolds, so there's no bung to run the EGR pipe. I've fooled the DPFE into thinking the EGR is present and the EGR remains in place, just with no vacuum line connected to the nipple and the bottom is plugged with a fitting.

Initially, I got a P0171 code, so I swapped out the O2s from the 99 set to the 2000 Explorer set I'm currently using. Cleared the code, drove it 12 miles. I then idled it for about 30 minutes another day. The next day, I pulled the plugs and found that cylinder 3 was ever so slightly tanned on the white insulating portion surrounding the electrode. All others were white like new. I bought a new plug and installed it in cylinder 3. I used a spark tester to verify that all cylinders are getting spark. Due to the fact that my primary wiring's connector on the LH coil pack that feeds cylinder 3 was cracked, I swapped it out with a spare that I had from another 5.0L Explorer motor.

I then removed the plenum and all injectors. I applied +12V to each injector individually and sprayed carb cleaner through them to verify that they were functioning and all of them had the 4 stream spray pattern. Replaced the injectors and checked resistance at the PCM connector through the harness to verify a complete circuit on all 8.

I then performed a dry, cold compression test on the engine and got 118 to 125PSI across all cylinders. Seems low, but I think it's because it's cold and dry. No one cylinder stood out. While doing that, cylinder 7's terminal came off at the plug. I bought a new set of Duraspark Gold wires and installed them yesterday.

I then read online that there have been a few cases of low alternator voltage causing misfires, but usually throwing a code for bad cam position sensor (which I didn't have). Just in case, I removed my alternator and had Autozone test it today and it put out +15.08V.

I'm at a loss at this point. I figured I'd buy a pair of coil packs just in case and see if that fixes it, but other than that, I can't imagine what it could be. Any help will be greatly appreciated!
15.08 v from the alternator is high but the alternator DC voltage isn't what causes a cam code and misfire, its AC voltage from a bad diode in the alternator. Are you getting a misfire code or are you feeling the miss at moderate throttle? Are you getting any codes? Check for AC voltage from your alternator or unplug the alternator and drive it to see if the miss goes away.
 

Rangstang

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15.08 v from the alternator is high but the alternator DC voltage isn't what causes a cam code and misfire, its AC voltage from a bad diode in the alternator. Check for AC voltage from your alternator or unplug the alternator and drive it to see if the miss goes away.
Actually, I removed the alternator and had it tested. If the tester at Autozone checks for AC signal on the line, then it passed. If they do not, I don't have an answer at this point. I can try your suggestion later this week.
Are you getting a misfire code or are you feeling the miss at moderate throttle? Are you getting any codes?
I have put almost no miles on it since I swapped the O2s and cleared the code. As of yet, no additional codes.

The miss is less noticeable when the engine is cold at idle and under load. When it warms up, it frequently stalls and is more significant under acceleration. Under heavy acceleration, the truck accelerates well, but you can tell it's not at full power.
 

Rangstang

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Are you getting any codes?
Finally decided to drive it to work yesterday. It was definitely missing the whole time. Even tried to die when idling up to lights. I had to keep giving it a little gas. I did get a CEL on my way home. Turns out it's the same as the original one... P0141, so I'm still getting a lean condition on Bank 1. I did a little reading last night and found that it can be caused by a misfire, so I'm leaning that direction since that's what I have.

Check for AC voltage from your alternator or unplug the alternator and drive it to see if the miss goes away.
Still need to try this tomorrow. I will and let you know.
 

Rangstang

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Check for AC voltage from your alternator or unplug the alternator and drive it to see if the miss goes away.
I decided to give this a go tonight since it was easy. I both unplugged the connector and removed the B+ lead. Still has the miss.

I would do one thing at a time. Start with the plugs, then the coil packs, etc.
I already had ordered coil packs when I asked the question. Just changed them both out, no change. I'll give the plugs a try tomorrow. Looks like it's an issue on Bank 1 since I keep getting a lean condition code there. I'm really leaning toward cylinder #3 since that's the only plug that even looked slightly different. I'll change them all and post tomorrow.
 

Rangstang

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I'm really leaning toward cylinder #3 since that's the only plug that even looked slightly different. I'll change them all and post tomorrow.
Swapped out the full set of plugs. Cylinder #3 didn't look any different than any of the rest this time. Set all the gaps at .054" before installing. Still didn't fix it.

Since I have the P0141 code, I decided to verify continuity from the PCM and the underhood fuse panel to the O2 connectors. Hit 100%, so that's not the issue either.

I'm at a loss. I'm pretty well convinced it's an internal engine issue that's not showing up on the compression test. I won't be doing anything further for a while as I swapped the PCM to test it and used my SBB V33.02 Key Programmer to add the key which wouldn't work (it's a Ford thing). Needless to say, I decided to erase all keys like I've done many times on Civics and then add the key from the truck to the second PCM. It will not take and it's apparently wiped out my PATs controller (behind the passenger air bag) as even when I put my original PCM back in, it will not even turn over.
 

Rangstang

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Nobody seems too interested in helping me out at this point, maybe it's because there are too many posts to read. Here's a recap and what I've done altogether. I don't think I've missed anything.

Specs when first fired listed below:

5.0L engine from 95 Mustang GT 5.0L - not rebuilt, only replaced all gaskets and seals
Upper/lower intake, throttle body, injectors (new o-rings), and fuel rail from 2000 Explorer
Exhaust manifolds are new castings from 65 Mustang with 289 V8
DPFE sensor from 2000 Explorer
PCM, PCM harness, and transmission harness from 2000 Explorer
MAF sensor from 2000 Explorer
IAC and TPS from 2000 Explorer
Coil packs from 2000 Explorer
O2 sensors from 1999 Explorer
NEW Autolite Platinum spark plugs gapped to .054" and BWD spark plug wires

No EGR on this due to the fact that I'm using the early exhaust manifolds, so there's no bung to run the EGR pipe. I've fooled the DPFE into thinking the EGR is present and the EGR remains in place, just with no vacuum line connected to the nipple and the bottom is plugged with a fitting.

Initially, I got a P0171 code, so I swapped out the O2s from the 99 set to the 2000 Explorer set I'm currently using. Cleared the code, drove it 12 miles. I then idled it for about 30 minutes another day. The next day, I pulled the plugs and found that cylinder 3 was ever so slightly tanned on the white insulating portion surrounding the electrode. All others were white like new. I bought a new plug and installed it in cylinder 3. I used a spark tester to verify that all cylinders are getting spark. Due to the fact that my primary wiring's connector on the LH coil pack that feeds cylinder 3 was cracked, I swapped it out with a spare that I had from another 5.0L Explorer motor.

I then removed the plenum and all injectors. I applied +12V to each injector individually and sprayed carb cleaner through them to verify that they were functioning and all of them had the 4 stream spray pattern. Replaced the injectors and checked resistance at the PCM connector through the harness to verify a complete circuit on all 8.

I then performed a dry, cold compression test on the engine and got 127 to 135PSI across all cylinders (2nd test with a different gauge). Seems low, but I think it's because it's cold and dry. No one cylinder stood out. While doing that, cylinder 7's terminal came off at the plug. I bought a new set of Duraspark Gold wires and installed them.

I then read online that there have been a few cases of low alternator voltage causing misfires, but usually throwing a code for bad cam position sensor (which I didn't have). Just in case, I removed my alternator and had Autozone test it and it put out +15.08V. I also tried driving the truck with the alternator hot lead and connector unplugged (running off battery) to verify no pulsating DC causing the issue.

Replaced the coil packs... nothing. Swapped out to another set of new plugs. Cylinder #3 didn't look any different than any of the rest this time. Set all the gaps at .054" before installing. Still didn't fix it.

Since I have the P0171 code, I decided to verify continuity from the PCM and the underhood fuse panel to the O2 connectors. Hit 100%, so that's not the issue either.

The truck idle is kind of rough once warm and sometimes stalls. It accelerates decently, but lacks power. I started removing injector connectors, one at a time initially this morning and found that the idle would be a bit rougher, the engine reved slower, and it even backfired sometimes. I got 1-5 cylinders done and quit for now as the others are very hard to reach in addition to the fact that the change was so significant on each that I believe I'm barking up the wrong tree in addition to the fact that it's a Bank1 issue, not Bank2.

I took a closer look at the OBD II scanner that I've got and found that it gets real time data from the sensors, so I warmed it upt and took it for a drive. I noticed that the LT FTRM1 was around 20-25% and the ST and LT FTRM2 hover around 0.0% for both. I read that a high fuel trim that decreases as the idle increases is likely a vacuum leak. So the next day I brought it up to 190 degrees and tested the theory. At around 900-1000RPM (wants to stall), I was getting around 20.3% for B1 LT trim occasionally jumping to 28.0% when it was about to stall, at 1500-1600RPM it's around 10.5%, but at 2500-2600RPM it jumps back up to 20.3% and is solid. According to what I've read on multiple sites, it's unlikely to be a vacuum leak as the B1 long term fuel trim should continue to decrease and it does not?

1. I checked all four contacts on the Bank1 front O2 sensor to all other 100 points in the PCM connector for shorts - none found. Lowest resistance is 43k ohms, so it's unlikely that I have a harness issue.
2. I also swapped the Bank1 and Bank2 front O2s and the LT fuel trim for Bank1 was still in the 24% range.
3. Sprayed brake cleaner and ether around the passenger intake ports with no effect.
4. I double checked each injector in the passenger bank for clicks using a stethoscope that I bought and they all appear to be working. I could hear clicking on the fuel rail itself, although the clicks seem a bit louder by the connector on each injector.
5. Removed the Bank1 front O2 connector and noted that the Bank1 LT trim jumped up to 42% and it didn't improve idle or acceleration.
 

Jbrown1238

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Nobody seems too interested in helping me out at this point, maybe it's because there are too many posts to read. Here's a recap and what I've done altogether. I don't think I've missed anything.

Specs when first fired listed below:

5.0L engine from 95 Mustang GT 5.0L - not rebuilt, only replaced all gaskets and seals
Upper/lower intake, throttle body, injectors (new o-rings), and fuel rail from 2000 Explorer
Exhaust manifolds are new castings from 65 Mustang with 289 V8
DPFE sensor from 2000 Explorer
PCM, PCM harness, and transmission harness from 2000 Explorer
MAF sensor from 2000 Explorer
IAC and TPS from 2000 Explorer
Coil packs from 2000 Explorer
O2 sensors from 1999 Explorer
NEW Autolite Platinum spark plugs gapped to .054" and BWD spark plug wires

No EGR on this due to the fact that I'm using the early exhaust manifolds, so there's no bung to run the EGR pipe. I've fooled the DPFE into thinking the EGR is present and the EGR remains in place, just with no vacuum line connected to the nipple and the bottom is plugged with a fitting.

Initially, I got a P0171 code, so I swapped out the O2s from the 99 set to the 2000 Explorer set I'm currently using. Cleared the code, drove it 12 miles. I then idled it for about 30 minutes another day. The next day, I pulled the plugs and found that cylinder 3 was ever so slightly tanned on the white insulating portion surrounding the electrode. All others were white like new. I bought a new plug and installed it in cylinder 3. I used a spark tester to verify that all cylinders are getting spark. Due to the fact that my primary wiring's connector on the LH coil pack that feeds cylinder 3 was cracked, I swapped it out with a spare that I had from another 5.0L Explorer motor.

I then removed the plenum and all injectors. I applied +12V to each injector individually and sprayed carb cleaner through them to verify that they were functioning and all of them had the 4 stream spray pattern. Replaced the injectors and checked resistance at the PCM connector through the harness to verify a complete circuit on all 8.

I then performed a dry, cold compression test on the engine and got 127 to 135PSI across all cylinders (2nd test with a different gauge). Seems low, but I think it's because it's cold and dry. No one cylinder stood out. While doing that, cylinder 7's terminal came off at the plug. I bought a new set of Duraspark Gold wires and installed them.

I then read online that there have been a few cases of low alternator voltage causing misfires, but usually throwing a code for bad cam position sensor (which I didn't have). Just in case, I removed my alternator and had Autozone test it and it put out +15.08V. I also tried driving the truck with the alternator hot lead and connector unplugged (running off battery) to verify no pulsating DC causing the issue.

Replaced the coil packs... nothing. Swapped out to another set of new plugs. Cylinder #3 didn't look any different than any of the rest this time. Set all the gaps at .054" before installing. Still didn't fix it.

Since I have the P0171 code, I decided to verify continuity from the PCM and the underhood fuse panel to the O2 connectors. Hit 100%, so that's not the issue either.

The truck idle is kind of rough once warm and sometimes stalls. It accelerates decently, but lacks power. I started removing injector connectors, one at a time initially this morning and found that the idle would be a bit rougher, the engine reved slower, and it even backfired sometimes. I got 1-5 cylinders done and quit for now as the others are very hard to reach in addition to the fact that the change was so significant on each that I believe I'm barking up the wrong tree in addition to the fact that it's a Bank1 issue, not Bank2.

I took a closer look at the OBD II scanner that I've got and found that it gets real time data from the sensors, so I warmed it upt and took it for a drive. I noticed that the LT FTRM1 was around 20-25% and the ST and LT FTRM2 hover around 0.0% for both. I read that a high fuel trim that decreases as the idle increases is likely a vacuum leak. So the next day I brought it up to 190 degrees and tested the theory. At around 900-1000RPM (wants to stall), I was getting around 20.3% for B1 LT trim occasionally jumping to 28.0% when it was about to stall, at 1500-1600RPM it's around 10.5%, but at 2500-2600RPM it jumps back up to 20.3% and is solid. According to what I've read on multiple sites, it's unlikely to be a vacuum leak as the B1 long term fuel trim should continue to decrease and it does not?

1. I checked all four contacts on the Bank1 front O2 sensor to all other 100 points in the PCM connector for shorts - none found. Lowest resistance is 43k ohms, so it's unlikely that I have a harness issue.
2. I also swapped the Bank1 and Bank2 front O2s and the LT fuel trim for Bank1 was still in the 24% range.
3. Sprayed brake cleaner and ether around the passenger intake ports with no effect.
4. I double checked each injector in the passenger bank for clicks using a stethoscope that I bought and they all appear to be working. I could hear clicking on the fuel rail itself, although the clicks seem a bit louder by the connector on each injector.
5. Removed the Bank1 front O2 connector and noted that the Bank1 LT trim jumped up to 42% and it didn't improve idle or acceleration.
How did you make out with swapping ECM's? I wish I could be more help but it sounds like you have covered everything I can think of.
 

Rangstang

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How did you make out with swapping ECM's? I wish I could be more help but it sounds like you have covered everything I can think of.
Couldn't try the other ECM due to PATS and the inability to add a key with my programmer (Ford issue). I think I'm going to yank the intake tomorrow and replace the gaskets, inspect it closely and hope for the best.
 

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