Hey guys,

I really hope someone can help me out.

I've got a 2006 Ford Ranger V6 3.0.

I've now invested over $1500 and I still can't seem to fix this prob. Just had the heads replaced as per the diagnostics of the dealer (vacuum leak -- compression probs).

But, I'm still getting the same basic problem: slight smell of gas at start up and rough idle. Compression is now OK.

It's got: new plugs, new plug wires, cleaned MAF, cleaned throttle body, cleaned IAC.

What's my next best step?

Any help would be soooo appreciated. This is driving me nuts!!

MJ

 

To add to the list: also has a new fuel filter -- and no codes popping up.

 

Welcome to FTE. You've been busy on this one!!!!

On the gas smell on start up, maybe suspect the vapor recovery system. Check all vacuum lines & fittings to it, the vapor recovery charcoal canister & solenoid thats computer controlled to open on start up, so that engine vacuum can suck the stored gas tank vapors out, to help in start up. If any of these vacuum hoses, fittings, or the canister are disconnected, poorly attached, cracked, vacuum hoses are dryrotted, soft, or or other wise not tight fitting, vapors can leak out & cause a raw gas fume smell & if vapors can leak out, air can be sucked in to cause an unmetered vacuum leak, that can cause a rough idle.

Also check the PCV valve & it's rubber hose & valve cover grommet for a tight fit, or if it's past time, replace the PCV valve. If the PCV valve sticks open, or is worn such that it doesn't seat well, it'll also mess with fuel trim, or act as an uncalculated for vacuum leak & mess with fuel trim, as that uncalculated air flow leak isn't being monitored by the MAF sensor.

Did you clean the MAF sensor with a non residual cleaner that said it was formulated just for cleaning the MAF sensor, like CRC MAF sensor spray, ect & waited for it to cool before cleaning, didn't touch, or poke the elements with the straw when cleaning & kept it squeeky clean on re-installation, such that your certain it's not damaged or contaminated????

Did you use the specified factory plugs & wires or aftermarket products???? Were the new ignition wires checked end to end for continuity & proper resistance??? Just because they're new, doesn't automatically earn em a pass, I've seen plenty of bad new parts right out of the box.
Did you also check the new plugs for proper gap & resistance & for chips, or hair line cracks in the internal & external ceramic insulators & torqued them in to spec??? Are you certain none were damaged on change out & all plug wires were routed as the Factory had them & you used the stand-off wire looms to keep the wires in place & that the wires are plugged in good on both ends????
Have you done a check at night, to see if any arcs or sparks are present along the plug wires or boots?????

Do you have a CEL lit, if so, have the computer scanned for trouble codes & post All code numbers found. Most autoparts stores will do it at no cost, if the CEL is lit.

Some thoughts for pondering, let us know what you find.

 

Pawpaw,

Thanks so much for the detailed response! Much appreciated.

I'm going to check on the points you mentioned and post a response. Currently, there are no codes.

I did notice this morning that when I started the vehicle, it didn't start idling rough right away, took about 30 seconds, which I'm thinking could be a sensor issue -- because I've read the most of the sensors are not online right away and the computer is going by default settings.

Also, there was no gas smell -- which seems only to crop up after the truck is already warmed up and has only be sitting for a few minutes before I restart it.

Any chance it could be the IAC sensor? Even after I cleaned it, it looked pretty caked w/ carbon on the inside sensor.

One other piece of info -- the truck only has 65K miles.

Thanks again -- more soon.

MJ

 

If the rough idle problem is because of low rpm & the IAC being really dirty then it belongs on your suspect list imo.

Seeing as how it has 65K on it & the rough idle doesn't come about right away, is a good clue, so maybe add lazy O2 sensors to your suspect list.
It takes about that long for them to heat up & come on line, to begin providing feedback to the computer, so if they're giving slow feedback, it could cause an idle problem.

More thoughts for your suspect list, keep us posted.

 

I'm not sure if this is the best way to check the o2 sensors -- but I disconnected, one at a time, started the truck and tested the idle. I was able to get to 2 of the 3 and it didn't seem to change the idle problem. It could be the third -- but I wasn't able to get to it -- yet.

Any tips on checking the o2 sensors? Is this an accurate method of identifying the culprit?

Also, I did notice on this round that when I start the truck, there is an audible click that I can hear from the cab about 5 seconds in and then it will start to idle rough. Not sure what's kicking in that causes the click. The idle isn't really bad but it's enough to be an annoyance and I'm sure it's effecting my gas mileage.

 

Well I suppose disconnecting the O2 sensors one at a time is one method of checking them, though maybe unconventional.

If you have a DVM, you could back probe the O2 sensors, to see if their switching range & speed is normal. If your DVM will also measure frequency, you could get an idea what their switching speed is also.
A scantool that'll display PID's is the easiest way to monitor O2 sensor switching range & speed.

The third/downstream O2 sensor, is for monitoring how the cat converter is doing it's job, so disconnecting will not affect engine idle.

The "click" your hearing may be the A/C compressor cycling on, so turn the Heater/AC control to OFF & listen to see if the click stops & the rough idle clears. If so, suspect the cleaned but still dirty IAC.

Again, is your idle rpm low when the engine is rough????

 

Pawpaw -- you're a wealth of information. Thank you!

Yes, the rpm is low (slightly) when the idle is rough. It definitely idles rough both with or w/ out heater/ac.

It looks like it could be that last o2 sensor wedged up in the engine. I'll give it a go.

Keep ya posted,

MJ

 

OK -- here's an update.

Finally decided to take the truck into the mechanic. He checked all sensors, and EGR Valve and couldn't find a problem. They checked checked for vacuum leaks. Compression is good.

Here's the list:
It is misfiring on cylinders 2 and 3 - intermittently
The longer it's running, the worse it is
It seems to idle fine at least the first 5 to 10 seconds
Smell of gas at start up that comes through vents

I'm concerned it might be an electrical problem. Something is heating up and failing on a circuit board.

Could it be clogged fuel injectors? Is it more likely a air/fuel prob?

Any suggestions on how to move from here. I'm at a loss.

 

One other thought. I just saw this:

When an injector is not flowing at an optimum rate it causes the o2 sensor to read the unburnt oxygen resulting in a lean condition. The computer compensates by increasing the "on" time of all the injectors in the older multiport systems where the injectors fire simultaneously. This can create an overly rich fuel condition in the other cylinders.

That would explain the smell of gas at start up. If it is fuel injectors and they are so clogged that they are causing rough idle. What's the best way to clean and test? Just use some techron in the tank? Seafoam better?

Thanks,

MJ

 

Post All of the trouble code Numbers the gararge found.

 

If there is crud in the IAC, you may also have carbon/crud build-up in the throttle body. That can cause idle problems and rich running. There is a special cleaner for throttle bodies. Use that; don't use carb. cleaner.

 

Pawpaw,

Here's the codes:

<table class="DiagnosticReportDataList" cellpadding="0" cellspacing="0"><tbody><tr class="Header"><th colspan="2"><table width="100%" border="0" cellpadding="0" cellspacing="0"><tbody><tr><td style="margin: 0px; padding: 0px; background-color: Transparent;" valign="top" align="left">MIL DTC</td> <td style="margin: 0px; padding: 0px; background-color: Transparent; font-weight: normal; text-align: right;" valign="top" align="right"> </td> </tr> </tbody></table> </th> </tr> <tr class="Content"> <th style="width: 150px;" valign="top" align="left" nowrap="nowrap">P0303</th> <td valign="top"> <table width="100%" border="0" cellpadding="0" cellspacing="0"> <tbody><tr> <td style="margin: 0px; padding: 0px; vertical-align: top;" valign="top" align="left">Cylinder Number 3 Misfire Detected</td> <td style="margin: 0px; padding: 0px;"> </td> </tr> </tbody></table> </td> </tr> </tbody></table> <table class="DataList" width="100%" border="0" cellpadding="0" cellspacing="2"> <tbody><tr> <td valign="top">Conditions For Setting This Code: </td> </tr> <tr> <td valign="top">Possible Causes: </td> </tr> <tr> <td valign="top">Monitor Information: </td> </tr> </tbody></table>
<table class="DiagnosticReportDataList" cellpadding="0" cellspacing="0"> <tbody><tr class="Header"> <th colspan="2"> <table width="100%" border="0" cellpadding="0" cellspacing="0"> <tbody><tr> <td style="margin: 0px; padding: 0px; background-color: Transparent;" valign="top" align="left">Pending Codes</td> <td style="margin: 0px; padding: 0px; background-color: Transparent; font-weight: normal; text-align: right;" valign="top" align="right"> </td> </tr> </tbody></table> </th> </tr> <tr class="Content"> <th style="width: 150px;" valign="top" align="left" nowrap="nowrap">P0303</th> <td valign="top"> <table width="100%" border="0" cellpadding="0" cellspacing="0"> <tbody><tr> <td style="margin: 0px; padding: 0px; vertical-align: top;" valign="top" align="left">Cylinder Number 3 Misfire Detected</td> <td style="margin: 0px; padding: 0px;"> </td> </tr> </tbody></table> </td> </tr> </tbody></table> <table class="DataList" width="100%" border="0" cellpadding="0" cellspacing="2"> <tbody><tr> <td valign="top">Conditions For Setting This Code: </td> </tr> <tr> <td valign="top">Possible Causes: </td> </tr> <tr> <td valign="top">Monitor Information: </td> </tr> </tbody></table>
<table class="DiagnosticReportDataList" cellpadding="0" cellspacing="0"> <tbody><tr class="Content"> <th style="width: 150px;" valign="top" align="left" nowrap="nowrap">P0316</th> <td valign="top"> <table width="100%" border="0" cellpadding="0" cellspacing="0"> <tbody><tr> <td style="margin: 0px; padding: 0px; vertical-align: top;" valign="top" align="left">Misfire in the First 1000 Revolutions</td> <td style="margin: 0px; padding: 0px;"> </td> </tr> </tbody></table> </td> </tr> </tbody></table> <table class="DataList" width="100%" border="0" cellpadding="0" cellspacing="2"> <tbody><tr> <td valign="top">Conditions For Setting This Code: </td> </tr> <tr> <td valign="top">Possible Causes: </td> </tr> <tr> <td valign="top">Monitor Information: </td> </tr> </tbody></table>
<table class="DiagnosticReportDataList" cellpadding="0" cellspacing="0"> <tbody><tr class="Header"> <th colspan="2"> <table width="100%" border="0" cellpadding="0" cellspacing="0"> <tbody><tr> <td style="margin: 0px; padding: 0px; background-color: Transparent;" valign="top" align="left">Stored Codes</td> <td style="margin: 0px; padding: 0px; background-color: Transparent; font-weight: normal; text-align: right;" valign="top" align="right"> </td> </tr> </tbody></table> </th> </tr> <tr class="Content"> <th style="width: 150px;" valign="top" align="left" nowrap="nowrap">P0316</th> <td valign="top"> <table width="100%" border="0" cellpadding="0" cellspacing="0"> <tbody><tr> <td style="margin: 0px; padding: 0px; vertical-align: top;" valign="top" align="left">Misfire in the First 1000 Revolutions</td> <td style="margin: 0px; padding: 0px;"> </td> </tr> </tbody></table> </td> </tr> </tbody></table> <table class="DataList" width="100%" border="0" cellpadding="0" cellspacing="2"> <tbody><tr> <td valign="top">Conditions For Setting This Code: </td> </tr> <tr> <td valign="top">Possible Causes: </td> </tr> <tr> <td valign="top">Monitor Information: </td> </tr> </tbody></table>
<table class="DiagnosticReportDataList" cellpadding="0" cellspacing="0"><tbody><tr class="Content"><th style="width: 150px;" valign="top" align="left" nowrap="nowrap">P0301</th> <td valign="top"> <table width="100%" border="0" cellpadding="0" cellspacing="0"> <tbody><tr> <td style="margin: 0px; padding: 0px; vertical-align: top;" valign="top" align="left">Cylinder Number 1 Misfire Detected</td></tr></tbody></table></td></tr></tbody></table>
<table width="100%" border="0" cellpadding="0" cellspacing="0"><tbody><tr><td style="margin: 0px; padding: 0px; background-color: Transparent;" valign="middle" align="left">Freeze Frame Information</td> <td style="margin: 0px; padding: 0px; background-color: Transparent; font-weight: normal; text-align: right;" valign="top" align="right"></td> </tr> </tbody></table> <table id="freezeFrameTable" style="width: 100%; margin: 0px 0px 15px;" border="0" cellpadding="0" cellspacing="2"><tbody><tr> <td style="font-weight: bold;">Parameter Description</td> <td style="font-weight: bold;">Value</td> </tr> <tr> <td style="padding: 5px 0px 0px;">DTC for which Freeze Frame was Stored</td> <td style="padding: 5px 0px 0px;">P0303</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Fuel System 1 Status</td> <td style="padding: 5px 0px 0px;">Closed Loop</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Fuel System 2 Status</td> <td style="padding: 5px 0px 0px;">Not Supported</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Calculated LOAD Value</td> <td style="padding: 5px 0px 0px;">41.18 %</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Engine Coolant Temp</td> <td style="padding: 5px 0px 0px;">190.40 °F</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Short Term Fuel Trim - Bank 1</td> <td style="padding: 5px 0px 0px;">-2.34 %</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Long Term Fuel Trim - Bank 1</td> <td style="padding: 5px 0px 0px;">-20.31 %</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Short Term Fuel Trim - Bank 2</td> <td style="padding: 5px 0px 0px;">3.13 %</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Long Term Fuel Trim - Bank 2</td> <td style="padding: 5px 0px 0px;">4.69 %</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Engine RPM</td> <td style="padding: 5px 0px 0px;">716.00 rpm</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Vehicle Speed Sensor</td> <td style="padding: 5px 0px 0px;">0.00 mph</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Ignition Timing Advance #1 Cylinder</td> <td style="padding: 5px 0px 0px;">18.00 °</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Intake Air Temperature</td> <td style="padding: 5px 0px 0px;">100.40 °F</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Air Flow Rate Mass Air Flow Sensor</td> <td style="padding: 5px 0px 0px;">0.55 lb/min</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Absolute Throttle Position</td> <td style="padding: 5px 0px 0px;">18.43 %</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Oxygen Sensor Output Voltage (B1-S1)</td> <td style="padding: 5px 0px 0px;">0.11 V</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Short Term Fuel Trim (B1-S1)</td> <td style="padding: 5px 0px 0px;">-2.34 %</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Oxygen Sensor Output Voltage (B1-S2)</td> <td style="padding: 5px 0px 0px;">0.41 V</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Short Term Fuel Trim (B1-S2)</td> <td style="padding: 5px 0px 0px;">99.22 %</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Oxygen Sensor Output Voltage (B2-S1)</td> <td style="padding: 5px 0px 0px;">0.10 V</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Short Term Fuel Trim (B2-S1)</td> <td style="padding: 5px 0px 0px;">3.13 %</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Oxygen Sensor Output Voltage (B2-S2)</td> <td style="padding: 5px 0px 0px;">0.24 V</td> </tr> <tr> <td style="padding: 5px 0px 0px;">Short Term Fuel Trim (B2-S2)</td> <td style="padding: 5px 0px 0px;">99.22 %</td></tr></tbody></table>
The more I've driven it, the more I'm convinced it's a air/fuel mix prob -- and most likely a bad sensor. These are the stats from my OBDII. The CEL come on today as I was running at idle, then held it steady just above idle - giving it just a little gas.

I did put in a bottle of Redline Fuel Injector Cleaner and blew it out on the freeway. It didn't seem to help much.

Michigan66,

Yes, it could be a prob with the IAC valve -- although I cleaned both the throttle and IAC quite thoroughly -- I thought.

Thanks again for any insights on this.

MJ

 

Any other thoughts on this, anyone? I'm really at a loss as to the next step.

 

Well something is going on in cyl bank one, as you have random misfire codes for cyl 1 & 3 & the -20.31% bank one fuel trim number confirms your suspension that fuel trim is amiss & bank one is the problem child.
Question is, whats up with the fuel trim on that bank????

Maybe consider doing some basic tests to establish a firm baseline, like under load battery voltage, KOEO & KOER fuel pump pressure & leak down & a series of tests with a vacuum gauge. Those tests will sorta give you an idea whats going on with the injectors, & engine mechanicals, like gasket leaks, sticking valves, fuel injectors, or piston rings.

Seeing as how you've posted smelling fuel on a start, weeping fuel injectors should probably be on your suspect list, so the fuel pressure & leak down test part of the KOEO & KOER fuel pressure test could shed some light on that idea.

Maybe also check the intake manafold fastner torque & closely inspect any vacuum line connections in that area.

If you have a scantool, also consider doing a cyl balance test & see what that suggests.

Edit: Here is an easy to read mini tutorial on fuel trim http://www.aa1car.com/library/fuel_trim_wellsmfg.pdf
A TSB that might apply if the above tests or a compression test point to it. http://ww2.justanswer.com/uploads/BO...ssfire_tsb.pdf
Let us know what you find.