ben_2_go
Well-Known Member
- Joined
- Aug 24, 2007
- Messages
- 362
- Reaction score
- 428
- Location
- Third rock from sun
- Vehicle Year
- 2001
- Make / Model
- Furd
- Engine Type
- 2.5 (4 Cylinder)
- Engine Size
- 2.5 Scrap
- Transmission
- Automatic
- 2WD / 4WD
- 2WD
- Tire Size
- 235-75-R15
- My credo
- None at all.
@RonD can you add any advice on this?
Let's start over from the beginning a few months back. Symptoms = Rough and variable idle, stalls when stopping, down on power, spark knock under any load level, and sometimes while coasting. This was not a gradual thing that happened. I was driving and everything was normal. Stopped at a red light and the truck died. Restarted fine with a low erratic idle.
Truck is 2001 2.5L 4R44E automatic 2wd no modifications at all. Engine/trans has never been touched except to do scheduled maintenance.
Well, same code I've been getting, but with different info with code. Problem still unresolved. Before the code said, "EVAP small leak detected", and nothing else. Screen shot shows the new info. Here is a list of what I have done since this started. Somethings I replaced due to age and it was maintenance time. Somethings I replaced because they're known to throw a P0442 code. Truck is a daily driver. I put about 100 miles a week on it.
I drained and refilled the fuel tank with fresh 93 gas.
new Fuel filter
New IAC
New purge valve-corrected the stalling when stopping issue, didn't improve erratic idle or spark knock
New timing belt
new cam position sensor connector- improved overall running condition, didn't improve erratic idle or spark knock
new PCV valve and hose
new ignition coils
new spark plugs
new spark plug wires
new egr valve
new DPFE sensor and connector-Corrected a DPFE code, improved overall running condition, didn't improve erratic idle or spark knock
New EGR/DPFE hoses
new EGR to manifold hard line
new intake gaskets
replace hose and check valve to brake booster
Several new vacuum hoses I thought were suspect and old.
I've sprayed all kinds of stuff around the intake and vacuum lines looking for leaks. Nothing changed the idle. Smoke test showed no issues. Checked heat/AC controls for vacuum leaks and no issues there. Checked the vacuum accumulator (aka the black ball) with no issues found. The only thing I haven't replaced is the evap canister solenoid and the fuel tank pressure sensor. I don't know what else to try. Everything I have done has improved the idle to the point it no longer dies when I stop. Nothing has helped the erratic idle or spark knock issue. I've had two well established shops, that my friends own, look over the truck. They all come back to bad IAC valve. I've been through 4 including the OE. The OE unit cleaned up is the only one that doesn't cause stalling issues. If I do the tests on the IAC and throttle position sensor, they all check out. I'm not talking about the unplug/replug tests. I'm talking about the full on diagnostic tests using a scan tool and electric multimeter just like any quality shop would perform. I am at a complete loss. I have no other vehicle to drive. I know I am damaging the engine running these hills and mountains with the truck spark knocking the entire time I am driving.
I was an ASE certified tech from '1993-2003 when I dropped out of the industry to pursue my aviation career. I've never been defeated so badly by a vehicle, ever! I'm almost to the point of parting out the truck. I won't sell a bad running vehicle, ever.
Let's start over from the beginning a few months back. Symptoms = Rough and variable idle, stalls when stopping, down on power, spark knock under any load level, and sometimes while coasting. This was not a gradual thing that happened. I was driving and everything was normal. Stopped at a red light and the truck died. Restarted fine with a low erratic idle.
Truck is 2001 2.5L 4R44E automatic 2wd no modifications at all. Engine/trans has never been touched except to do scheduled maintenance.
Well, same code I've been getting, but with different info with code. Problem still unresolved. Before the code said, "EVAP small leak detected", and nothing else. Screen shot shows the new info. Here is a list of what I have done since this started. Somethings I replaced due to age and it was maintenance time. Somethings I replaced because they're known to throw a P0442 code. Truck is a daily driver. I put about 100 miles a week on it.
I drained and refilled the fuel tank with fresh 93 gas.
new Fuel filter
New IAC
New purge valve-corrected the stalling when stopping issue, didn't improve erratic idle or spark knock
New timing belt
new cam position sensor connector- improved overall running condition, didn't improve erratic idle or spark knock
new PCV valve and hose
new ignition coils
new spark plugs
new spark plug wires
new egr valve
new DPFE sensor and connector-Corrected a DPFE code, improved overall running condition, didn't improve erratic idle or spark knock
New EGR/DPFE hoses
new EGR to manifold hard line
new intake gaskets
replace hose and check valve to brake booster
Several new vacuum hoses I thought were suspect and old.
I've sprayed all kinds of stuff around the intake and vacuum lines looking for leaks. Nothing changed the idle. Smoke test showed no issues. Checked heat/AC controls for vacuum leaks and no issues there. Checked the vacuum accumulator (aka the black ball) with no issues found. The only thing I haven't replaced is the evap canister solenoid and the fuel tank pressure sensor. I don't know what else to try. Everything I have done has improved the idle to the point it no longer dies when I stop. Nothing has helped the erratic idle or spark knock issue. I've had two well established shops, that my friends own, look over the truck. They all come back to bad IAC valve. I've been through 4 including the OE. The OE unit cleaned up is the only one that doesn't cause stalling issues. If I do the tests on the IAC and throttle position sensor, they all check out. I'm not talking about the unplug/replug tests. I'm talking about the full on diagnostic tests using a scan tool and electric multimeter just like any quality shop would perform. I am at a complete loss. I have no other vehicle to drive. I know I am damaging the engine running these hills and mountains with the truck spark knocking the entire time I am driving.
I was an ASE certified tech from '1993-2003 when I dropped out of the industry to pursue my aviation career. I've never been defeated so badly by a vehicle, ever! I'm almost to the point of parting out the truck. I won't sell a bad running vehicle, ever.
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