99 ranger 3.0 #2 cylinder misfire violent shaking

[svtkidd23]

Truck is a 1999 ranger 3.0 4x4 with manual trans.

It was driving perfectly fine and started idling terrible. Its done this before I changed plugs wires and it was fine.

This time I was in traffic truck has been fine for 5k miles. Waiting in traffic stop and go stop and go it had same idle...

Dug deeper into the truck found a tornado in the intake LOL. pulled that out cleaned MAF and IAC. Had 2 codes on my scanner P0171 Bank 1 too lean
and P0302 Cylinder #2 misfire.

Changed plug again on #2. Checked and verifyed spark on #2 cylinder. Still running rough as can be. I checked the injector and it had .29 ohms so i replaced that. Lean code went away. Still missing. yet no code.


I found a hole intake and plugged it with a bolt it came from oil filler cap vent to the intake. Something somewhere has a vac leak I think... We have spark and fuel. Unless the compression is bad.

Pulled plug and started it and it sounded like it had a lot of compression, wont know till tomorrow.

sprayed carb cleaner all around the motor and nothing changed rev wise..

New intake gasket and

New coil!

Cliffs:
Truck idles terrible and shakes truck violently until 2800 ish up
Coil is good
New plugs, wires, injector
po171 and po0302
plugged intake from oil filler cap
carb cleaner caused no change in idle around hoses
No power... driving me insane

 

[RonD]

Yes, compression test
Remove all spark plugs to get good cranking speed, and then test each cylinder.
Cold engine is fine for the info you are after
With good battery and crank speed you should expect 170psi, 3.0l is 9.3:1 compression ratio

Lean code is probably from the misfire
O2 sensors see "oxygen" not fuel
When you have a misfire then none of the air(oxygen) in that cylinder gets burned up, it just gets dumped into the exhaust and the O2 sees it, and reports high oxygen levels, which is Lean, then computer adds more fuel and #1 and #3 are running rich, but too much air(misfire) is still there, so computer sets code and tells you about the problem, CEL comes on.
Computers are not smart, they are fast and consistent, but not smart

 

[ranger1997]

For info my 97 2.3 did that along with flashing CEL light. Lean bank 2 iirc at 250K. Also tried injector with no help.

Ended up being a broken valve spring. Just something to consider. Good luck.


Sent from my iPhone using Tapatalk

 

[svtkidd23]

Wouldn't a broken valve spring cause a lot of noise? And compression fall like crazy?

 

[svtkidd23]

Yes, compression test
Remove all spark plugs to get good cranking speed, and then test each cylinder.
Cold engine is fine for the info you are after
With good battery and crank speed you should expect 170psi, 3.0l is 9.3:1 compression ratio

Lean code is probably from the misfire
O2 sensors see "oxygen" not fuel
When you have a misfire then none of the air(oxygen) in that cylinder gets burned up, it just gets dumped into the exhaust and the O2 sees it, and reports high oxygen levels, which is Lean, then computer adds more fuel and #1 and #3 are running rich, but too much air(misfire) is still there, so computer sets code and tells you about the problem, CEL comes on.
Computers are not smart, they are fast and consistent, but not smart

What's that have to do with #2 cylinder? 1/3?

I did the compression test and they were all great 170-180psi

 

[RonD]

Valve train issues can show up on compression test, as too low or too high compression in that cylinder.

1/3 are on the same bank, computer runs fuel mix based on banks.
When #2 misfires it dumps oxygen in the common exhaust manifold on that bank, the O2 sensor on that bank sees that extra oxygen as Lean exhaust, computer adds more fuel to that bank, 1/2/3, but if #2 is still missing exhaust still shows Lean so computer sets Lean code for that bank.

If #2 shows no difference in compression then you are down to spark and fuel

#2 and #6 share the same coil, these spark plugs fire at the same time, so are wired in series, you can reverse these wires on the coil and see if miss moves to #6, indicating an issue in the coil secondary wiring.
The ICM(ignition control module) was moved inside the computer in '95 and they have been very reliable since then.
If you have an old timing light you could hook it up to #2 and see if spark is stable, steady rhythm no missing pulses, having spark is different than having it at the right time and at a steady beat.

You can test for a bad coil but as odd as this sounds testing won't tell you if a coil is good, the problem is with the low ohms and the rapid charging and discharging that needs to happen in a "good" coil.
Ohms testing a coil can tell you for sure if it is bad, but passing the test doesn't mean it is good, in engine running situation.


Simple fuel test is to unplug the coil wire connector, so coil won't fire, then crank engine.
Pull out #1, #2, #3 spark plugs and compare how much fuel is on each.

 

[csargents1546]

As far as using carb cleaner to detect a vacuum leak. With the computer in control of the fuel mix, typically will not see an increase in rpms, but with a live data scanner the short term fuel trims will crazy. Speck for those is plus or minus 10.
I would try replacing the coil pack. Fixed a lit of 3.0 with a coil pack.

 

[svtkidd23]

Valve train issues can show up on compression test, as too low or too high compression in that cylinder.

1/3 are on the same bank, computer runs fuel mix based on banks.
When #2 misfires it dumps oxygen in the common exhaust manifold on that bank, the O2 sensor on that bank sees that extra oxygen as Lean exhaust, computer adds more fuel to that bank, 1/2/3, but if #2 is still missing exhaust still shows Lean so computer sets Lean code for that bank.

If #2 shows no difference in compression then you are down to spark and fuel

#2 and #6 share the same coil, these spark plugs fire at the same time, so are wired in series, you can reverse these wires on the coil and see if miss moves to #6, indicating an issue in the coil secondary wiring.
The ICM(ignition control module) was moved inside the computer in '95 and they have been very reliable since then.
If you have an old timing light you could hook it up to #2 and see if spark is stable, steady rhythm no missing pulses, having spark is different than having it at the right time and at a steady beat.

You can test for a bad coil but as odd as this sounds testing won't tell you if a coil is good, the problem is with the low ohms and the rapid charging and discharging that needs to happen in a "good" coil.
Ohms testing a coil can tell you for sure if it is bad, but passing the test doesn't mean it is good, in engine running situation.


Simple fuel test is to unplug the coil wire connector, so coil won't fire, then crank engine.
Pull out #1, #2, #3 spark plugs and compare how much fuel is on each.

As far as using carb cleaner to detect a vacuum leak. With the computer in control of the fuel mix, typically will not see an increase in rpms, but with a live data scanner the short term fuel trims will crazy. Speck for those is plus or minus 10.
I would try replacing the coil pack. Fixed a lit of 3.0 with a coil pack.

Found out the new injector I got was for the non flex fuel therefore has a different hat with .2 ohms more giving it. A closed command.

Swapped injectors and fired of course gave it a dead cylinder where new injector is

Ordered oem replacement xl5 a2a
Not a b2b



I didnt even bother changing or switching new injector because it being new why fail..

never assume anything i guess!

thanks amazon! friday will have new injector for 65$ cheaper then dealer

 

[svtkidd23]

it even passed noid test just wont fire off! diff tip

 

[txgocartB3000]

Thanks for the update.

As a side note, has anyone used any of the injector rebuilding companies out there?

Ray

 

[Rearanger]

As a side note, has anyone used any of the injector rebuilding companies out there?

Witchhunter.com, not technically "rebuilding" but inspects, tests, cleans, reports before/after. $22 per + about $15 shipping both ways.

 

[txgocartB3000]

Yeah, that's the one.

Have you used them?

Reason I ask is because I was thinking of grabbing a couple from the junk yard, having them cleaned and keeping them in a safe storage place.

Seems cheaper but I have been known to do foolish things before.

Sorry for the hi-jack...

Back to normal programming.

Ray