rough time

[paulbecker]

My Contour (98 2.5 Duratec, 122K miles) has been down for some time now. I've been driving my wife's car and tinkering around on it on the weekends but I'm clueless.

When it got cold here in December, it would occasionally die when I pulled into the driveway. I would start it again immediately and it would seem fine.

Then one day on the way home from work I rounded a corner and the CEL flashed and it was running rough. I nursed it towards home and went to the local AutoZone (yeah, I know) to get the codes read.

I told you earlier that I was clueless - I lost the codes, but I do recall that I got misfires codes and system lean codes, both banks.

I put on new plugs (gapped at 054) & wires, and checked the grounds around the coil pack to no avail. Here's what it does today...

I start it up, let it do its normal high-idle down to low-idle bit, then rev it to 2k RPM and hold it there. It stays there for maybe 7 seconds then starts to nosedive by itself (foot hasn't moved), ending up at about 1.2k RPM. If I take my foot off of the gas it dies. If I instead goose it a couple of times it is fine, and I can repeat that exercise as many times as I'd like with the engine cold. Not sure about warm.

I'm starting to suspect a fuel or fuel delivery problem, but I really have no clue. Any suggestions?

Thanks,
Paul

 

[Tony2005]

Take it to Autozone or Advance and have the codes read again. Then post the exact codes. In the meantime, check for broken or loose hoses or tubing. You should hear a hissing sound. If not spray the areas with carb cleaner to try and locate the vacuum leaks. When the idle changes, you found the leak.

There could be many reasons for the car not idling well (TPS, TB, IAC valve, MAF, IAT, vacuum leaks, bad spark plugs, bad sp wires, etc.). Post the new codes and we can go from there.

I take it you have an automatic. You should always post year, engine, tranny and mileage. Better to put in your signature.

 

[paulbecker]

Ok, I borrowed an OBD II scanner from AutoZone.

I get:
P1151
P0302
P0303

Oh, and I have an automatic transmission, sorry for leaving that out earlier.

Paul

 

[Tony2005]

Per TSB,

P1151 - Lack of HO2S-21 Switch, Indicates Lean.

When an HO2S sensor indicates lean at the end of a test, the system is trying to correct for an over-lean condition. The code is set when the fuel control system no longer detects switching for a calibrated amount of time.

Electrical:
· Short to VPWR or VREF in harness or HO2S
· HO2S circuit shorted to Ground
· Water in harness connector
· Open circuit
· Corrosion or poor mating terminals and wiring
· Damaged HO2S
· Damaged PCM (other DTCs should be present)

Fuel System:
· Excessive fuel pressure (stuck fuel pressure regulator, restricted fuel return lines, etc.)
· Leaking/contaminated fuel injectors or fuel pressure regulator
· Low fuel pressure or running out of fuel (fuel pump concern, fuel supply line restrictions, low fuel level, etc.)
· Vapor recovery system (stuck VMV, etc.)

Induction System:
· MAF contamination
· Air leaks between MAF and throttle plate
· PCV system / Other vacuum leaks
· Improperly seated engine oil dipstick

EGR System:
· Leaking gasket
· Stuck EGR valve / Leaking diaphragm or EVR

Base Engine:
· Oil overfill
· Incorrect cylinder compression


I suggest you do the simple ones first. Check for vacuum leaks, SP wires not seated properly, damaged wiring to Bank 2 Upper O2 sensor (this is the O2 sensor next to the oil filter, left of exhaust manfold if you are standing in front of the car. Look in between the radiator and the front of the car).

How old is the O2 sensor? If more than 75K miles, then maybe it is time to change it.

How old are the spark plugs and SP wires? If more than 100K miles, then it is also time to change them.

Check those items first as the P0302 and P0303 (misfire in cylinders 2 and 3) could be because of those items too.

Edit. Make sure spark wires are in this order. Note the 4-6-5 for the coil pack.

Firewall side
4- 6 -5 <--coil pack
3-2-1

1-2-3 <--engine
4-5-6
Radiator side