Sputtering turned into missing

[Scallywagon]

Been talking about this in my build thread > Here <

So my hesitation theory went right out, the fuel filter was fine and even after I put another brand new one in, the sputtering hadn't stopped.

So I checked the plugs and they were bad, dark bad. They were brand new too after I did the head

I swapped in better looking plugs, fixed most of the "sputter" which we now know is a miss

I checked compression, 150 across the board

I checked the ignition coil, it's fine

I swapped the o2 sensor to a known good one, still missing but this + the better plugs has me running with MUCH less misses

A) Miss-Firing
B) Rich Mixture

So what could cause me to have a rich mixture besides the o2 sensor? Bad ECU? Also as a note I have had my idle running a bit high ~900rpm could this be why its running so rich? Normal is ~750rpm right, I'll fix that.

[Scallywagon]

I should also note I stuck a clean air filter in.

So I'm thinking, fuel pump, injectors, FPR, ECU or Plug Wires

[jlevie]

Run the suite of fuel system tests in the Bentley manual to see if the fuel system is at fault. Then have a shop run a smoke test on the intake to see if there are any intake leaks. Once those tests are done and indicated repairs are completed we can move on to the other possible issues.

[Scallywagon]

Run the suite of fuel system tests in the Bentley manual to see if the fuel system is at fault. Then have a shop run a smoke test on the intake to see if there are any intake leaks. Once those tests are done and indicated repairs are completed we can move on to the other possible issues.

Will do.

[Scallywagon]

Okay I'm thinking ECU, or Distributor Cap/Rotor, or valve job or a mix of the three

Am I up the right alley here?

Also could my ICV have anything to do with it idling funny/stalling?

Its surging in idle now and even stalled out along with the misses, and still running obviously rich. Power, and compression, even vacuum seem fine

[Scallywagon]

I also have a trashed radiator plug, could it be sending a cold signal forcing a rich mixture?

Ugh, any help is appreciated on my DD

[Scallywagon]

Going to stomp test to see what it tells me

is there a computer that can properly read the motronic?

[dinanm3]

my thoughts for running ruff miss fire,adjust maf wheel,bad plug wire,vacume leak,injector not working, corroded connection- the round one under the intake forget the name c#,adjust valves.

[dinanm3]

Okay I'm thinking ECU, or Distributor Cap/Rotor, or valve job or a mix of the three

Am I up the right alley here?

Also could my ICV have anything to do with it idling funny/stalling?

Its surging in idle now and even stalled out along with the misses, and still running obviously rich. Power, and compression, even vacuum seem fine

yes it can take it off clean it put some wd .

[Scallywagon]

Okay cool adjusting the valves now, then I'll clean up the ICV some more, throw a new cap/rotor on then swap the ignition wires and computer and see where that leaves me

[Scallywagon]

adjust maf wheel, injector not working, corroded connection- the round one under the intake forget the name c#

Not sure what these 3 things mean ^^

Whats a MAF wheel how do I test it or see if its fouling

Bad Injectors would mean lean right? not rich?

I know the connection you're talking about(ECV) but how can I test it?

[jlevie]

Ignore the advice about the MAF wheel. There is little chance that the AFM is causing what you described.

Start with the fuel system and intake tests I mentioned above. Only after those have been ruled out as a cause should you consider other possibilities

[dinanm3]

Not sure what these 3 things mean ^^

Whats a MAF wheel how do I test it or see if its fouling

Bad Injectors would mean lean right? not rich?

I know the connection you're talking about(ECV) but how can I test it?

the connector i noticed when i moved it the car stalled or idle changed
un twist it.than look at all the pins to see if green .If they are sand them spray with electrical connection cleaner .the maf has a black cover with a wheel inside it the wheel can be turned in either direction leaner or richer but mark were you started.i would do this last after everything else ruled out.bad injectors could cause run ruff or miss fire put a screw driver to the injector and see if its ticking.hope i help you rule some things out sorry about my writing i know i suck ebonics

[Deutschland über alles]

try this and http://www.youtube.com/watch?v=-11J8XawQtc
read this part first i had to find this info too and here is my copy and pasted answer

1)Here is the procedure I followed.

First some background information. The narrow band O2 sensor in our cars
is designed to keep the engine operating within a very narrow range around the ideal 14.5:1 air to fuel mixture. The O2 sensor is basically a little chemical generator that will vary in output voltage between 0 and 1 volt depending on how much oxygen is in the gases exiting the engine. If the engine is running too rich, the output voltage will rise to 0.7 volts or higher. If the engine is running lean, then the output will drop to 0.2 volts or less.

The Motronic ECU tries to keep the voltage output of the 02 sensor between 0.4 and 0.5 volts by increasing or decreasing the fuel injector pulse width compared to the internal reference map. A couple times a second, the ECU checks the 02 sensor output voltage, the throttle position, the flow rate through the AFM, the idle bypass setting (telling it how much air is bypassing the AFM), the air temperature, engine speed and engine temperature and looks up the fuel injector pulse width and timing advance to use. The ECU then adds or subtracts a correction factor based on the 02 sensor reading. The problem is the ECU can only add or subtract so much from the reference value. Therefore, if there are any significant errors in any of the input readings the car will run too rich or too lean. That is why you need a new ECU chip if you swap the fuel injectors or make any other significant changes to the car's engine.

O.K. now back to what I did.
AFM it is a mystery to most drivers.

If you do not feel comfortable with them just print and take them to the shop of your choice.

Do a good leak check using a spray ether starting fluid on the intake.

Here are the adjustment procedures.
Air Flow Meter Testing:

Before you test the AFM, you need to make sure you have NO AIR leaks anywhere. Check and double check!

A simple way to determine if you NEED to adjust the AFM is as follows:

- Remove the air filter housing and elbow leading up to the AFM.

- With the engine idling, gently push on the AFM flapper-door. If the idle rpm increases and the engine smoothes out, then your AFM needs adjustment.

- An additional test. Repeat the above step, but hold the throttle as steady as possible at 3,000 rpm. If the highest rpm and smoothest operation occur only when you advance the door position, then you need an AFM adjustment.


Several things I NEED to point out. The toothed wheel mentioned below MUST be held firmly as you loosen the retaining. If you let this wheel slip uncontrolled or rotate freely, you will be SO SCREWED! Also, I found that I only had to adjust my wheel by two cogs, i.e. VERY little. What this did, was loosened the resistance of the flapper door and hence enriched my fuel mixture slightly. You will be tempted to adjust it much more, but you shouldn't even think about doing this. Small increments are better. I would try only one cog first and you can always increase another cog or two if you feel the need. Also, you will want to rotate the wheel in a counter clockwise manner. This will loosen (or enrich you fuel mixture) the flapper door. IMPORTANT: Be sure to use some type of bright paint to make a mark on both the wheel and the reference hole, so you will know where you started, in case you want to return to the original wheel position. I've scanned and posted a diagram of what you'll see under the black cover.

Also, I chose to not reseal the black plastic cap on the bottom of the AFM. Rather, I secured it temporarily with a couple of linked zip ties wrapped around the AFM in such a way to hold the cap on. I then ran the car for a few days to see how it performed. If I like it, I took the zip ties off and resealed with silicone sealant. I've done several this way and it is pretty straight forward.


Calibrating the AFM
Theory:

The amount of fuel fed to the engine is determined by the 1)FUEL PRES and 2)PULSE WIDTH (length time wise) to the injector.

The pulse width is affected by several factors (inc. but not limited to PROM, Temp Sensor, O2 Sensor, AFM Flap Position*...)

*Up to about 3500 rpm only

We are going to modify the Flap Pos'n Sensor by making LESS air open the flap WIDER (Wider=More Fuel). Usually these engines are set at the edge of leanness when new, and as they age, they go leaner, making for poor performance and idle. By "calibrating" we are simply maximizing the engine output for the other parameters using the AFM to "tune" the system.

Doing the Job:

1)Unhook the air cleaner elbow from the AFM.
2) Rotate the AFM 180 deg (M30) so the black plastic rounded-corner plastic cap is on the top (watch the wires).While the AFM is upside down, center the idle CO screw (count turns) in its range.
3) CAREFULLY cut the sealant (RTV) and pry the cap off.
4) Notice the screw holding pressure on the toothed wheel (looks like a gear).
5) Paint a mark on the wheel and the post as a reference mark for future re-setting if desired.
6) Disconnect O2 Sensor @ firewall, start car and warm to operating temp.
7) Set RPM to above idle (1500-1800 rpm is fine)and hold it there mechanically.
8) Loosen clamp screw and rotate to maximize rpm.
9) Tighten screw.
10)Check idle smoothness. If it is rough, note present toothed wheel position and try moving 1 to 2 teeth either direction until idle smoothes out.
11)Adjust idle CO screw for edge-of-lean smooth idle. (Remember screw works backwards from carb idle adj.) (i.e. CW=Richer)

As an alternative, you can simply adjust the toothed wheel for the smoothest idle (at idle rpm of course) in step "8" above and have done with it. You probably won't notice a big difference at running speeds anyway.

[dinanm3]

try this and http://www.youtube.com/watch?v=-11J8XawQtc
read this part first i had to find this info too and here is my copy and pasted answer

1)Here is the procedure I followed.

First some background information. The narrow band O2 sensor in our cars
is designed to keep the engine operating within a very narrow range around the ideal 14.5:1 air to fuel mixture. The O2 sensor is basically a little chemical generator that will vary in output voltage between 0 and 1 volt depending on how much oxygen is in the gases exiting the engine. If the engine is running too rich, the output voltage will rise to 0.7 volts or higher. If the engine is running lean, then the output will drop to 0.2 volts or less.

The Motronic ECU tries to keep the voltage output of the 02 sensor between 0.4 and 0.5 volts by increasing or decreasing the fuel injector pulse width compared to the internal reference map. A couple times a second, the ECU checks the 02 sensor output voltage, the throttle position, the flow rate through the AFM, the idle bypass setting (telling it how much air is bypassing the AFM), the air temperature, engine speed and engine temperature and looks up the fuel injector pulse width and timing advance to use. The ECU then adds or subtracts a correction factor based on the 02 sensor reading. The problem is the ECU can only add or subtract so much from the reference value. Therefore, if there are any significant errors in any of the input readings the car will run too rich or too lean. That is why you need a new ECU chip if you swap the fuel injectors or make any other significant changes to the car's engine.

O.K. now back to what I did.
AFM it is a mystery to most drivers.

If you do not feel comfortable with them just print and take them to the shop of your choice.

Do a good leak check using a spray ether starting fluid on the intake.

Here are the adjustment procedures.
Air Flow Meter Testing:

Before you test the AFM, you need to make sure you have NO AIR leaks anywhere. Check and double check!

A simple way to determine if you NEED to adjust the AFM is as follows:

- Remove the air filter housing and elbow leading up to the AFM.

- With the engine idling, gently push on the AFM flapper-door. If the idle rpm increases and the engine smoothes out, then your AFM needs adjustment.

- An additional test. Repeat the above step, but hold the throttle as steady as possible at 3,000 rpm. If the highest rpm and smoothest operation occur only when you advance the door position, then you need an AFM adjustment.


Several things I NEED to point out. The toothed wheel mentioned below MUST be held firmly as you loosen the retaining. If you let this wheel slip uncontrolled or rotate freely, you will be SO SCREWED! Also, I found that I only had to adjust my wheel by two cogs, i.e. VERY little. What this did, was loosened the resistance of the flapper door and hence enriched my fuel mixture slightly. You will be tempted to adjust it much more, but you shouldn't even think about doing this. Small increments are better. I would try only one cog first and you can always increase another cog or two if you feel the need. Also, you will want to rotate the wheel in a counter clockwise manner. This will loosen (or enrich you fuel mixture) the flapper door. IMPORTANT: Be sure to use some type of bright paint to make a mark on both the wheel and the reference hole, so you will know where you started, in case you want to return to the original wheel position. I've scanned and posted a diagram of what you'll see under the black cover.

Also, I chose to not reseal the black plastic cap on the bottom of the AFM. Rather, I secured it temporarily with a couple of linked zip ties wrapped around the AFM in such a way to hold the cap on. I then ran the car for a few days to see how it performed. If I like it, I took the zip ties off and resealed with silicone sealant. I've done several this way and it is pretty straight forward.


Calibrating the AFM
Theory:

The amount of fuel fed to the engine is determined by the 1)FUEL PRES and 2)PULSE WIDTH (length time wise) to the injector.

The pulse width is affected by several factors (inc. but not limited to PROM, Temp Sensor, O2 Sensor, AFM Flap Position*...)

*Up to about 3500 rpm only

We are going to modify the Flap Pos'n Sensor by making LESS air open the flap WIDER (Wider=More Fuel). Usually these engines are set at the edge of leanness when new, and as they age, they go leaner, making for poor performance and idle. By "calibrating" we are simply maximizing the engine output for the other parameters using the AFM to "tune" the system.

Doing the Job:

1)Unhook the air cleaner elbow from the AFM.
2) Rotate the AFM 180 deg (M30) so the black plastic rounded-corner plastic cap is on the top (watch the wires).While the AFM is upside down, center the idle CO screw (count turns) in its range.
3) CAREFULLY cut the sealant (RTV) and pry the cap off.
4) Notice the screw holding pressure on the toothed wheel (looks like a gear).
5) Paint a mark on the wheel and the post as a reference mark for future re-setting if desired.
6) Disconnect O2 Sensor @ firewall, start car and warm to operating temp.
7) Set RPM to above idle (1500-1800 rpm is fine)and hold it there mechanically.
8) Loosen clamp screw and rotate to maximize rpm.
9) Tighten screw.
10)Check idle smoothness. If it is rough, note present toothed wheel position and try moving 1 to 2 teeth either direction until idle smoothes out.
11)Adjust idle CO screw for edge-of-lean smooth idle. (Remember screw works backwards from carb idle adj.) (i.e. CW=Richer)

As an alternative, you can simply adjust the toothed wheel for the smoothest idle (at idle rpm of course) in step "8" above and have done with it. You probably won't notice a big difference at running speeds anyway.

exactly what he said!!
and i did mention this would be last thing i would do !