97 Camry rough idle then stall only when warm
 

Hi guys,

Hoping someone can help me with this.

Got a 97 Camry with a 2.2L 4 cyl. Idles until warm then gets rough and stalls.

Previously had P0300, P0302 and P0303 codes. Then it started idling rough and stalling. Replaced the plugs and wires. No codes since then but still stalls.

Ignition coil resistance is good. O2 sensors are good. Injectors are good. Broke the Coolant Temperature Sensor and replaced. IAC is good, got the throttle body off now and am cleaning it and IAC.

Before I removed it, I broke the vacuum hose to the VSV. With this disconnected (vacuum leak past the throttle) it initially idles high then idles correct when warm.

Any ideas on this problem? I'll have the throttle body clean and back on soon but I'm wondering if this makes sense to anyone out there.

Thanks,

Brian

Did you clear the codes or did they go away on their own after repairs?

Did you replace the coolant sensor for the ECU? When idling rough, disconnect the wiring plug from the sensor and determine if this improves things.

Which VSV has the broken hose?

Might be a sticking or open EGR when engine hot.

I cleared the codes and they have not returned.

Yes its the two-pronged connector which I assume is for the ecu. It would not start at all with this broken. Should I still try disconnecting it when idling?

The vsv (I believe) is just behind the air filter. Is there another one?

Putting the cleaned throttle body and IAC back on tomorrow so I will repost with the results.

Is this the EGR VSV?

The EVAP system has an VSV.

If you replaced the IAC assume it is OK.

Could be the IAC. Post back with results.

Latest lack of success.
 

Alright, reinstalled the IAC (same sensor but cleaned and resistance tested) and the Throttle Body. No change unfortunately.

Sprayed some carb cleaner in the EGR and tested plunger for movement. Moved fine, stayed closed (as far as I could tell) the entire time.

I believe the vsv is for the evap. A picture is attached with the hose outlined.
Again I assume this hose isn't relevant beyond it being a significant vacuum leak which helps when warm.

With this hose detached, the engine maintains a stable idle of 1100 rpm (live feed from scanner).

No new codes and no idea what to try next.

Did you also clean the intake air control valve that is bolted under the throttle body?

The idle would pick up if the VSV hose is detached as more air is allowed into the intake.

Yes the VSV should be closed (no extra air allowed into engine) until computer sets points are reached one being engine warm and car being driven. The extra air is then not an issue.

Since the issue occurs when engine warm. It might be assumed something is going from cold to warm which may be the problem.

Suggest obtaining something called cold freeze spray or like this name. This a spray canned chemical that evaporates on surfaces to cool them down. The item is used to check for overheating issues with electronics. An internet search will find it.

When the problem starts. Spray the various sensors, ign coil including pickups such as cam or crank sensor one at a time and determine if this makes a difference.

If this engine still has a distributor as the photo appears to show. Determine if there are pickup coils inside it. Toyota started shifting to external pickups before eliminating the distributor. Check for a bad pickup coil when warm by checking resistance hot/cold.

When checking any sensor resistance, make sure it is steady and does not start to shift with time.

Update, No Success
 

So I've done some work on the car; had to rethread a stripped out spark plug on cyl 3 and replaced the throttle body intake hose because it was leaking.

Bought the freeze spray but haven't had a chance to test individual sensors.

It still stalls when warm unsurprisingly but there is a pretty obvious engine noise and stutter. Wondering if this rings any bells. This is idling, again with a hose disconnected on the throttle body (it would stall out otherwise).

Still No Luck
 

Sprayed the sensors around the TB with freeze spray and the ignition coils. No change. Also disconnected the A/F O2 sensor but no change. Tried to test it but couldn't get a reliable voltage from it.

Heres two videos of the engine noise; first one with no vacuum leak from cold, second from warm with vacuum leak to prevent stalling.



Using a screwdriver as a stethoscope, the sound is loudest at the waterpump. Not sure if this adds any useful information.

Any suggestions would be greatly appreciated...

The noise is not normal. Use a section of hose as a stethoscope and narrow down its location.

Recheck water pump area. Under the timing cover in the middle upper area are the belt idler bearings. Check alternator, AC compressor, PS pump for noise.

The vacuum leak will increase idle speed to prevent stalling? Which hose are you removing again?