I changed my fuel dampener , having rpm fluctuation, and stalls on idle

[azrangerman85]

My 3.0 1998 Ford ranger is stalling at idle, it bucks while driving 30-40mph , weak acceleration. Sometimes it begins to rev up and wants to go forward by itself while im at a stop light. This is scary because its dangerous in an intersection. I changed my fuel dampener, because I had a fuel dampener leaking fuel droplets before, and now its still a mild problem . Can this be EGR?

 

[RonD]

The stalling can be EGR but not the higher RPMs

The computer uses the IAC(idle air control) valve on the upper intake to control idle RPMs
It has 2 wires
After engine is warmed up and idling, unplug the 2 wire connector
Idle should drop to 500, barely running, or engine may stall, either is GOOD, it means no vacuum leaks
If idle doesn't drop then there is a vacuum leak

Because of the variations I would change PCV Valve if you haven't in the last year or so, PCV valve is a "planned vacuum leak", but if it gets dirty it's valve can stick causing variations in idling and stalling

Clean MAF sensor, always, causes idle issues and bucking


EGR system has a DPFE sensor that reads the pressure near the EGR valve and farther away, computer compares these pressure to see if EGR valve is opening and how much it is opening
Because its an emissions system its heavily monitored, so sets EGR codes at the drop of a hat
You don't mention a CEL(check engine light) being on, and assuming light works, it would be on if EGR was staying open causing a stall

 

[azrangerman85]

The stalling can be EGR but not the higher RPMs

The computer uses the IAC(idle air control) valve on the upper intake to control idle RPMs
It has 2 wires
After engine is warmed up and idling, unplug the 2 wire connector
Idle should drop to 500, barely running, or engine may stall, either is GOOD, it means no vacuum leaks
If idle doesn't drop then there is a vacuum leak

Because of the variations I would change PCV Valve if you haven't in the last year or so, PCV valve is a "planned vacuum leak", but if it gets dirty it's valve can stick causing variations in idling and stalling

Clean MAF sensor, always, causes idle issues and bucking


EGR system has a DPFE sensor that reads the pressure near the EGR valve and farther away, computer compares these pressure to see if EGR valve is opening and how much it is opening
Because its an emissions system its heavily monitored, so sets EGR codes at the drop of a hat
You don't mention a CEL(check engine light) being on, and assuming light works, it would be on if EGR was staying open causing a stall

My IAC is fairly new. My throttle control sensor is new. the wiring might be sketch but it has no breaks that im aware of. Also, I just changed the PCV so its not the pcv. the egr does look very old and rusted on the outside. MY CEL is on, its p1132, and p0172 . There is a lack of oxygen in the upstream, this to me is an indigation of vacuum leak, or clog in the egr . What are your thoughts?

 

[azrangerman85]

The stalling can be EGR but not the higher RPMs

The computer uses the IAC(idle air control) valve on the upper intake to control idle RPMs
It has 2 wires
After engine is warmed up and idling, unplug the 2 wire connector
Idle should drop to 500, barely running, or engine may stall, either is GOOD, it means no vacuum leaks
If idle doesn't drop then there is a vacuum leak

Because of the variations I would change PCV Valve if you haven't in the last year or so, PCV valve is a "planned vacuum leak", but if it gets dirty it's valve can stick causing variations in idling and stalling

Clean MAF sensor, always, causes idle issues and bucking


EGR system has a DPFE sensor that reads the pressure near the EGR valve and farther away, computer compares these pressure to see if EGR valve is opening and how much it is opening
Because its an emissions system its heavily monitored, so sets EGR codes at the drop of a hat
You don't mention a CEL(check engine light) being on, and assuming light works, it would be on if EGR was staying open causing a stall

My 1998 3.0 egr does not have a sensor on it. its just mechanical with a vaccuum port

 

[RonD]

It does have DPFE sensor, not connected to EGR valve, it has two Hoses on the EGR pipe to exhaust manifold and is connected by 3 wires to the computer
Ford moved it around but here is a picture of what it looks like: https://bob-ayers.smugmug.com/photos/124318500-L.jpg
2 hoses and a 3 wire connector

Is the new IAC Valve a Motorcraft or Hitachi brand?
If not then that could be the problem
Other 3rd party brands can work for awhile but can be unreliable because they are "stepper" type, and Rangers use solenoid type


P0172 System too Rich (Bank 1)
P1132 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Rich - Bank No. 1

When you have one bank(side) of a V6 engine or V8, showing O2 sensor code or 2, it can mean the O2 sensor is at end of life
They do wear out after 150k miles or 10-12 years
Its possible if Damper was leaking and fuel was being sucked in you could get Rich code on just one side of the engine, if you have cleared the codes and they came back after the damper repair then I would change both upstream O2 sensors if they are close to 10 years old

You could have a leaking injector on passenger side(bank 1) as well
Whats the MPG like recently?

 

[azrangerman85]

res to the comp

It does have DPFE sensor, not connected to EGR valve, it has two Hoses on the EGR pipe to exhaust manifold and is connected by 3 wires to the computer
Ford moved it around but here is a picture of what it looks like: https://bob-ayers.smugmug.com/photos/124318500-L.jpg
2 hoses and a 3 wire connector

Is the new IAC Valve a Motorcraft or Hitachi brand?
If not then that could be the problem
Other 3rd party brands can work for awhile but can be unreliable because they are "stepper" type, and Rangers use solenoid type


P0172 System too Rich (Bank 1)
P1132 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Rich - Bank No. 1

When you have one bank(side) of a V6 engine or V8, showing O2 sensor code or 2, it can mean the O2 sensor is at end of life
They do wear out after 150k miles or 10-12 years
Its possible if Damper was leaking and fuel was being sucked in you could get Rich code on just one side of the engine, if you have cleared the codes and they came back after the damper repair then I would change both upstream O2 sensors if they are close to 10 years old

You could have a leaking injector on passenger side(bank 1) as well
Whats the MPG like recently?

dont you say that dirty word injector. : ( I have bad mpg , but its been bad since the dampener . I just changed my fuel pump and put in a new one from NAPA a month ago, and no problems until now. The dampener was probably bad already . I just drove around the block and parked in front of a Taco bell with adequate lighting, I let it idle, and i pulled the IAC , it dropped RPM like you said . I then pulled the MAF connector and nothing changed at all (weird) . What are your thoughts? I havent changed oil in over a month, and the air filter might be dirty too (arizona does get dustY) but in the recent 4 years Ive never had a situation like this

 

[RonD]

The computer doesn't use MAF sensor or O2 sensors at idle, or WOT(wide open throttle), just FYI

Dirty MAF can cause stumbling when accelerating or cruising, and even though its not used at idle it can cause rough idle after warm up in average air WEIGHT, which is what MAF measures.

clear codes and see what comes back
Or get a Bluetooth OBD2 reader, $15-$25, and watch Live data while driving to see if O2s are working correctly

 

[azrangerman85]

The computer doesn't use MAF sensor or O2 sensors at idle, or WOT(wide open throttle), just FYI

Dirty MAF can cause stumbling when accelerating or cruising, and even though its not used at idle it can cause rough idle after warm up in average air WEIGHT, which is what MAF measures.

clear codes and see what comes back
Or get a Bluetooth OBD2 reader, $15-$25, and watch Live data while driving to see if O2s are working correctly

Yes, but I am stalling out on idle. it revs up high then down low below 500, down to 200 and then jumps high, then back down to stable, then drops again until it either stays stable or stalls out.

 

[azrangerman85]

The computer doesn't use MAF sensor or O2 sensors at idle, or WOT(wide open throttle), just FYI

Dirty MAF can cause stumbling when accelerating or cruising, and even though its not used at idle it can cause rough idle after warm up in average air WEIGHT, which is what MAF measures.

clear codes and see what comes back
Or get a Bluetooth OBD2 reader, $15-$25, and watch Live data while driving to see if O2s are working correctly

Could a 2 year old corroding battery do this?

 

[azrangerman85]

The computer doesn't use MAF sensor or O2 sensors at idle, or WOT(wide open throttle), just FYI

Dirty MAF can cause stumbling when accelerating or cruising, and even though its not used at idle it can cause rough idle after warm up in average air WEIGHT, which is what MAF measures.

clear codes and see what comes back
Or get a Bluetooth OBD2 reader, $15-$25, and watch Live data while driving to see if O2s are working correctly

I got a
P1401 DPFE (egr valve sensor)
P1504 (Idle control valve sensor) . I noticed dialectric grease on the connector . Should I remove the battery cables and clean the connectors off or leave the dialectric?Same on the DPFE
P1132 lack of upstream HO2s ( This caused by the egr valve/ dfpe?)
P0172 rich bank 1
P0175 rich bank 2

Now that these codes just came up finally after driving a little bit longer this evening, should I just change the DPFE ? the IAC is new, would the DPFE cause the IAC to react?

 

[RonD]

IAC valve is unrelated
What Brand is the IAC Valve?


Test for exhaust blockage using a vacuum gauge
Partially blocked exhaust would explain these codes, you would also have a loss of power at higher RPMs
P1401 DPFE (egr valve sensor)
P1132 lack of upstream HO2s
P0172 rich bank 1
P0175 rich bank 2

Get a long vacuum hose, and remove current vacuum hose from EGR Valve and attach longer hose to the EGR valve
Start engine
Use finger to see if removed EGR vacuum hose has vacuum present, it shouldn't, EGR Valve is only used after engine is warmed up and when RPMs/engine load is higher than idle
If there is vacuum on the hose then EGR solenoid is leaking, replace it

Suck on the longer vacuum hose, engine should start to stumble as exhaust gases come in thru EGR valve, release suction, stumbling should stop
Repeat until you are satisfied EGR valve is opening and closing as it should

Yes, if EGR valve is leaking exhaust gases into the engine when closed it could cause these codes

 

[azrangerman85]

IAC valve is unrelated
What Brand is the IAC Valve?


Test for exhaust blockage using a vacuum gauge
Partially blocked exhaust would explain these codes, you would also have a loss of power at higher RPMs
P1401 DPFE (egr valve sensor)
P1132 lack of upstream HO2s
P0172 rich bank 1
P0175 rich bank 2

Get a long vacuum hose, and remove current vacuum hose from EGR Valve and attach longer hose to the EGR valve
Start engine
Use finger to see if removed EGR vacuum hose has vacuum present, it shouldn't, EGR Valve is only used after engine is warmed up and when RPMs/engine load is higher than idle
If there is vacuum on the hose then EGR solenoid is leaking, replace it

Suck on the longer vacuum hose, engine should start to stumble as exhaust gases come in thru EGR valve, release suction, stumbling should stop
Repeat until you are satisfied EGR valve is opening and closing as it should

Yes, if EGR valve is leaking exhaust gases into the engine when closed it could cause these codes

I took the egr off, cleaned it with carb cleaner, sprayed the exhaust tube and put a foot of steel braided wire on a drill and cleaned it , put it back with a gasket after soaking the egr valve and internal with carb cleaner, the egr valve had a strong spring and seemed to work. I took my maf apart and cleaned it with maf cleaner. I cleaned iac and dpfe terminals . Now the only code left is p1504 and the two 172 and 175 codes . code 1401 and 1132 disappeared

 

[azrangerman85]

IAC valve is unrelated
What Brand is the IAC Valve?


Test for exhaust blockage using a vacuum gauge
Partially blocked exhaust would explain these codes, you would also have a loss of power at higher RPMs
P1401 DPFE (egr valve sensor)
P1132 lack of upstream HO2s
P0172 rich bank 1
P0175 rich bank 2

Get a long vacuum hose, and remove current vacuum hose from EGR Valve and attach longer hose to the EGR valve
Start engine
Use finger to see if removed EGR vacuum hose has vacuum present, it shouldn't, EGR Valve is only used after engine is warmed up and when RPMs/engine load is higher than idle
If there is vacuum on the hose then EGR solenoid is leaking, replace it

Suck on the longer vacuum hose, engine should start to stumble as exhaust gases come in thru EGR valve, release suction, stumbling should stop
Repeat until you are satisfied EGR valve is opening and closing as it should

Yes, if EGR valve is leaking exhaust gases into the engine when closed it could cause these codes

*Correction its p1401 that remained.

 

[RonD]

1996 Mazda B2300 here. Probably 250k+ miles (odo not working since 2009), replaced: plugs, wires, MAF, TBS, filters, fuel pump, regulator, up and down stream O2 sensors, cat converter, TPS, PCV and hoses. Replaced upper intake gasket, thermostat (195 degree), water pump, timing belt, serp and all idlers as well as power steering pump. Replaced fuel pump and regulator last week due to codes and new pump and regulator made no change to measured fuel pressure of 28 lbs at idle. Start vehicle hot or cold, will not idle. Engine speed fluctuates up to 2000 then when idles down dies. It launches ok from stop, but has to be run at 2000 rpm or more to keep from slowing down, if it's put in 4th below 55 to 60 mph, slows down. Top speed 65-70 mph in 4th does nothing unless going down hill with tailwind and tailgate down in 5th....not using oil, no smoke, not engine knocks, no sludge. Three ASE certified mechanics stumped, as well as I. HELP!

Welcome to TRS

You need to start your own thread in the 4 Cylinder section, or just in the General Section
You issues are not related to this thread because its a 3.0l V6 engine forum

You need a Vacuum gauge and a compression gauge to continue
You need to do a compression test FIRST, any time you have low power on any engine, compression is good or bad, no middle ground, so once that is off the table you can move on to spark or fuel issue
But if it IS a compression issue then chasing spark and fuel is a waste of time and money