Running rough

Tiny
DCB1971
  • MEMBER
  • 2002 FORD FOCUS
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 128,000 MILES
Im working on a ford focus vin 3 motor, I did a tuneup changed plugs wires air filter cleaned throttlebody maf and installed a new iac the problem is that the car is getting to much fuel at idle runs rough and there are no codes changed the o2's took the plugs back out they are black, with the car running I unplug the maf no differnce the car still runs, I unplug every sensor on the engine the car still runs no change im wondering if I have a bad ecc or does it need to be flashed, there are no vacuum leaks
Sunday, September 5th, 2010 AT 11:28 AM

15 Replies

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Hello,

It is running rich because of the misfire. Lets start by checking the compression please use this guide to see whats going on.

https://www.2carpros.com/articles/how-to-test-engine-compression

Please run down this guide and report back.
Was this
answer
helpful?
Yes
No
-1
Sunday, September 5th, 2010 AT 1:46 PM
Tiny
OIDAVEY
  • MEMBER
  • 0 POST
I had this problem and had no compression in #3 cylinder had to do a valve job, runs great!
Was this
answer
helpful?
Yes
No
Thursday, June 20th, 2019 AT 3:00 PM
Tiny
NEILSTER99
  • MEMBER
  • 2 POSTS
  • 2002 FORD FOCUS
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 187,000 MILES
Ok runs very poorly and when I pull the plug wire off of the cyclinder closest to the drivers side of the car it still runs. When I pull the plug wire off the other spark plugs it stalls. No warning lights on th dash, where do I start. Thanks. Neil
Was this
answer
helpful?
Yes
No
+1
Friday, June 21st, 2019 AT 1:42 PM (Merged)
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
How does it run with all wires connected? And is the check engine light on? Checking for spark is a bit different today than it was on older cars, if the wire is too far from the ground, you can damage modules!
Was this
answer
helpful?
Yes
No
Friday, June 21st, 2019 AT 1:42 PM (Merged)
Tiny
NEILSTER99
  • MEMBER
  • 2 POSTS
Well it runs terrible when all four are connected? That is the whole purpoes of my question it runs terrible. I also wrote in the question there are NO warning lights on? When u drive it as u get faster it seems to even out but hard to tell really only driving it in the city under 70k's. Is there any way to test for mudules without paying the dealer 120 plus tax. Neil
Was this
answer
helpful?
Yes
No
Friday, June 21st, 2019 AT 1:42 PM (Merged)
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
The only way to read B and U codes, to test for trouble with modules or data lines is with the right scan tool, Ford knows this and it keeps their service dept. busy, but when you turn the key to the on position does the check engine light come on? This is a built in check of the OBD II system. You have spark, so only three things remain to test, fuel pressure, compression, and the modules. So test what you can, fuel pressure and compression.

https://www.2carpros.com/car_repair_video/test_fuel_injection_pressure.htm
Go here and checkout our video.
And please post which model Focus you drive, se, svt, zts, ztw, zx3, zx5?
There is a Tech bulliten about sticky valves for the 2.0 SPI engine, it goes as follows:
2.0L SPI - ROUGH IDLE, LOW POWER AND/OR STALL AT IDLE WITH DTCS P0300- P0304 TECHNICAL SERVICE BULLETIN Reference Number(s): 04-9-1, Â Date of Issue: Â May 17, 2004 Superceded Bulletin(s): 02-9-1, Â Date of Issue: Â May 13, 2002 Related Ref Number(s): 01-4-13, 02-9-1, 04-9-1 ARTICLE BEGINNING DESCRIPTION DRIVEABILITY - ROUGH IDLE, LOW POWER AND/OR STALL AT IDLE WITH DIAGNOSTIC TROUBLE CODES (DTCS) P0300-P0304 STORED IN MEMORY - VEHICLES EQUIPPED WITH 2.0L SPI ENGINE ONLY ELECTRICAL - MALFUNCTION INDICATOR LAMP (MIL) ILLUMINATED - DIAGNOSTIC TROUBLE CODES (DTCS) P0300-P0304 STORED IN MEMORY - VEHICLES EQUIPPED WITH 2.0L SPI ENGINE ONLY ISSUE Some vehicles equipped with the 2.0L SPI engine may exhibit a malfunction indicator lamp (MIL) illuminated and diagnostic trouble codes (DTCs) P0300 through P0304 stored in memory. The vehicle may also have a rough idle or reduced power condition, and/or may stall at an idle. This may be caused by sticking exhaust valves due to excessive carbon build-up. ACTION Check for faulty fuel injectors and ignition wires. One or more exhaust valves may be temporarily sticking due to carbon build-up between the valve stem and guide. If the diagnostic checks point to a sticking exhaust valve, the cylinder head assembly may need to be replaced with a new level cylinder head assembly with revised valve guides, revised exhaust valves will also need to be installed to help prevent carbon build-up. Refer to the following Service Procedure for details. SERVICE PROCEDURE This condition usually results in misfire when the engine returns to idle after running approximately 2000 RPM or higher. FORD: 1997-2002 ESCORT; 2000-2002 FOCUS MERCURY: 1997-1999 TRACER NOTE: This article supersedes TSB 02-9-1 to update the service and part information. NOTE: THIS PROCEDURE APPLIES ONLY TO THE 2.0L SPI ENGINE.
1. Use the worldwide diagnostic system (WDS) to test for Power Balance with the engine at idle. Check for cylinder misfire. If misfire is occurring constantly, go to Step 3. If misfire is not occurring, attempt to induce misfire by performing the following step: a. Apply the parking brake and keep the transmission in Park or Neutral. Bring the engine to approximately 2800 RPM and hold for one (1) minute. Check the WDS Power Balance display while holding engine speed constant. Allow the engine to return to idle and watch the WDS Power Balance display for a misfiring cylinder. 2. If WDS Power Balance indicates a misfiring cylinder with the previous test, one or more exhaust valves may be intermittently sticking due to carbon build-up between the valve stem and guide. Replace the cylinder head with the new level cylinder head with revised valve guides. Once stock is exhausted of the loaded cylinder heads, the cylinder head will come bare so revised exhaust valves will need to be installed in place of the original valves. The revised valve guides and exhaust valves help prevent carbon build-up. Consult the appropriate model year Workshop Manual for removal and installation procedures for the Cylinder Head Assembly. 3. If WDS Power Balance did not indicate a misfiring cylinder with the previous test or a misfire is occurring constantly, the misfire may not be due to a sticking exhaust valve. Refer to the appropriate model year Powertrain Control/Emissions Diagnosis (PC/ED) Service Manual for further diagnosis. Other possible causes may be, worn or arcing ignition wires, base engine compression, fuel injectors, fuel injector harness resistance or PCM injector driver signal. Perform diagnosis and repair as necessary. 4. After completing either Step 2 or Step 3, replace the PCV Valve (YS4Z-6A666-AC) (Motorcraft EV-244) on model year 2000-2002 Focus or 2000-2002 Escort. Vacuum fluctuations from engine misfire may prematurely wear the PCV valve on those applications. NOTE: THE CYLINDER HEAD ASSEMBLIES LISTED BELOW WILL BE BARE CASTINGS ONCE SUPPLY OF LOADED HEADS IS EXHAUSTED, IN MOST CASES IT WILL BE NECESSARY TO REPLACE ONLY THE PARTS LISTED BELOW, ALL OTHER PARTS CAN BE REUSED.


https://www.2carpros.com/forum/automotive_pictures/62217_Sticky_valves_Focus_Escort_0002_1.jpg

Was this
answer
helpful?
Yes
No
+1
Friday, June 21st, 2019 AT 1:42 PM (Merged)
Tiny
MRSD
  • MEMBER
  • 1 POST
  • 2001 FORD FOCUS
Engine Mechanical problem
2001 Ford Focus 4 cyl Front Wheel Drive Automatic

After our last fill up my car started running rough at an idle. My husband said it sounds like it is missing.
It also has a Sulfur smell from the exhaust. The check engine light is now on. Until now this car has run like a kitten. My husband tryed changing the spark plugs to see if that would help. It did not.
Could it be the cad converter?
Was this
answer
helpful?
Yes
No
-2
Friday, June 21st, 2019 AT 1:42 PM (Merged)
Tiny
RICH CRITES
  • MECHANIC
  • 75 POSTS
That sounds like catalytic converter. Your check engine light is turned on because you may have a bad oxygen sensor.
Was this
answer
helpful?
Yes
No
Friday, June 21st, 2019 AT 1:42 PM (Merged)
Tiny
SNOOPT1
  • MEMBER
  • 5 POSTS
  • 2000 FORD FOCUS
  • 4 CYL
  • FWD
  • MANUAL
  • 165,000 MILES
Started when it was cold outside and happens more often then. When I start the car it doesn't hold a consistent idle. It will surge up a couple of times and eventually, within a couple of minutes, the idle will drop so low it usually stalls. When I drive the car it is perfect, no problems. After it is warmed up the idle will usually rev up when I come to a stop. I pull up to a light, stop, put it in nuetral and the engine will rev up. The only way to get it to stop is to put it in gear and let the clutch out a little. This will usually drop the idle back down and then it will idle fine. I put new plugs and wires on it, one of the wires was arking to the positive battery lead. I have had the ignition system flushed, although I am not sold that it really does anything. I have checked the plugs several times and they look good. There are no warning lights and the check engine light never comes on. Can I still pull codes off it if the light never comes on?
Was this
answer
helpful?
Yes
No
Friday, June 21st, 2019 AT 1:43 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
You can always scanned the computer anytime don't be surprise if it pops a code without the light coming on.

Clean out the Idle air control valve and test the throttle position sensor.

Here's how to clean the IAC valve:

Disconnect the air intake ductwork from the throttle body.

Start the engine, then increase and hold the idle speed to 1,000 to 1,500 rpm.

Spray the throttle cleaner or engine cleaner into the throat of the throttle body, aiming for the idle air bypass port (usually located on the side or top of the throttle body opening). Give this area a good dose of cleaner (about 10 second's worth).

Turn the engine off to allow the cleaner to soak into the IAC passageway.

Wait about three minutes.

Restart the engine, rev and hold at 1,000 to 1,500 rpm, and repeat the cleaning process again.

Turn the engine off again, and reattach the air intake ductwork to the throttle body.

Start the engine and rev and hold to 1,500 to 2,000 rpm until no white smoke is coming out of the exhaust pipe.

If this fails to make any difference, you can remove the IAC valve from the throttle body and spray cleaner directly on the tip of the valve and/or into the ports in the throttle body. Let the cleaner soak awhile, repeat as needed, then reinstall the IAC valve, start the engine and run it at 1,500 to 2,000 rpm as before until no white smoke is seen in the exahust.

If the idle speed still surges after this, the IAC valve is defective and needs to be replaced.
Was this
answer
helpful?
Yes
No
Friday, June 21st, 2019 AT 1:43 PM (Merged)
Tiny
SNOOPT1
  • MEMBER
  • 5 POSTS
Ok, thanks for the info. I will check on that first thing tonight. I will let you know what I find.
Was this
answer
helpful?
Yes
No
Friday, June 21st, 2019 AT 1:43 PM (Merged)
Tiny
SNOOPT1
  • MEMBER
  • 5 POSTS
I pulled the IAC off and cleaned it, however, it showed no signs of being dirty. The gasket was cracked a little but it didn't look bad enough to cause any problems. Is there any way to check the IAC to see if it is working? It is an $80 part and they won't accept it as a return if it doesn't fix the problem. Oh we ran the code reader and couldn't get it to pop a code either.

Any suggestions?
Was this
answer
helpful?
Yes
No
Friday, June 21st, 2019 AT 1:43 PM (Merged)
Tiny
SNOOPT1
  • MEMBER
  • 5 POSTS
I replaced the IAC and the idle still surges. It is a little better, but it still surges. We hooked up a reader and tried to pull a code, no joy. No matter what we do, we can't get it to pop a code.

Any other suggestions?

I thought maybe the Throttle Position Sensor, but I figured you'd see the problem through the entire RPM range.

ANyway, I am at a loss, my mechanice is at a loss. I just want to get the car to idle better.

Thanks in advance for any assistance you can offer.
Was this
answer
helpful?
Yes
No
+1
Friday, June 21st, 2019 AT 1:43 PM (Merged)
Tiny
CORKYBLONDE
  • MEMBER
  • 1 POST
  • 2001 FORD FOCUS
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 110,000 MILES
My car had the engine completely replaced less than 2 months ago and a few days ago I started it up and it started making a ticking sound. I had it towed to the dealer where I bought the engine, it has taken him 3 days to do a diagnostic on it and he said he added half a quart of oil to the engine it stopped ticking but now it runs rough and misfires. He said he doesn't know what it is. Help me!
Was this
answer
helpful?
Yes
No
Friday, June 21st, 2019 AT 1:43 PM (Merged)
Tiny
MHPAUTOS
  • MECHANIC
  • 31,937 POSTS
Hi there,

Some mechanic you have there! He will have to first check compressions, check injection pulse to all cylinders, check spark voltages on an oscilloscope check fuel pressure, check for vacuum leaks, check foe any set fault codes in the ECU, this is all standard procedures foe diagnosing a miss fire.

Mark (mhpautos)
Was this
answer
helpful?
Yes
No
Friday, June 21st, 2019 AT 1:43 PM (Merged)

Please login or register to post a reply.

Sponsored links