I have a 93 4 cyl Camry with a problem that none of the mechanics so
far, including the dealer, could fix. After driving for a while the
idle speed starts dropping until one stop light the engine stalls. It
looks like it will run for ever at highway speed. Also seems to be
heat related since it only happens in the summer. Here are the things
that have already been checked, repaired or replaced:

EGR valve
Thermostat
Temperature sensor
Distributer assembly
MAP sensor
ECU

I am getting very close to giving it to the Salvation Army. Does
anyone have
any other ideas? Have you seen this problem before? Thanks.

be

Erhan wrote:
This is a classic symptom of the EGR system not operating correctly.
There should be no exhaust gas recirculation (EGR) at idle and the
usual test for the EGR system is to apply vacuum to activate the valve
at idle and see if the engine dies to indicate the system is working.
I know you say the EGR valve has been replaced. Also check the vacuum
diaphragm and vacuum modulator for the EGR valve. Have these checked
with the engine hot and displaying these symptoms.
Another less likely possibility, but often not diagnosed, could be
excessive back pressure in the exhaust system from a partially
collapsed muffler or catalytic converter.

On May 10, 11:46 am, Erhan <bilal.er... (AT) gmail (DOT) com> wrote:


I had the exact same stall-at-red-light problem, and changing the EGR
Modulator did the trick.

http://groups.google.com/group/alt.a...54543b6662458e

Try getting one for cheap at the local junkyard (if they have Toyota
parts).

You might also look into a possible distributor O-ring slow oil leak.
I had one, but it didn't help my stalling any.

Best wishes,

Michael

On May 10, 4:27 pm, Daniel <nospampls2... (AT) yahoo (DOT) com> wrote:
Thanks. Actually the EGR valve was only cleaned with carb cleaner.

On May 10, 5:42 pm, mrdarr... (AT) gmail (DOT) com wrote:
Thank you. I'll give it a try.
One thing I don't understand though is if the EGR system is the
cause,
why do the symptoms show only under warm weather?

be

To quickly check the EGR modulator, get a free loaner MityVac vacuum
gauge from AutoZone. Connect the gauge to the hose from the modulator
that goes into the EGR valve. Do you read vacuum during idle? There
should be no vacuum from the modulator at idle, engine warm or cold.

Also, pull vacuum on the EGR valve. Does the engine quit? This is
assuming the EGR valve operates normally and isn't stuck open at all
times, but if so I would think too that the problem would be there
when the engine is cold.

If it happens only when warm then can you keep the engine running by
opening the throttle slightly? Idle Air Control valve on Camrys likes
to stick shut. However, pre-97 has other things like thermo-vacuum
valves etc that can cause problems too.

You can read about the IAC (on later 5SFEs) here. If it's the cause
then cleaning should help.
http://www.autosafety.org/article.php?did=972&scid=101


On May 10, 11:46 am, Erhan <bilal.er... (AT) gmail (DOT) com> wrote:

On May 10, 4:55 pm, johngd... (AT) hotmail (DOT) com wrote:

Say, John... would the EGR vacuum switching valve likely be a problem,
if he only stalls when it's warm out? Does it usually go bad? It's
just an electromagnet solenoid coil, right?

I suspected the VSV too, when troubleshooting my stalling problem, but
I stopped when the EGR modulator swap fixed it.

(Plus, the VSV is really hard to get to.)

Best wishes

Michael

Erhan wrote:
Online diagnosis is always a guess.
However, the EGR system will not operate until the engine reaches
operating temperature.

On May 11, 11:29 am, mrdarr... (AT) gmail (DOT) com wrote:
Is VSV the blue switch with two hoses coming out of it near the
coolant temp sensor?
There is no information about it in my Haynes manual

Erhan

On May 11, 11:17 am, Erhan <bilal.er... (AT) gmail (DOT) com> wrote:

I don't think so... I thought it was behind the intake manifold.
(Between the intake manifold and the dashboard.)

But I could be wrong.

Michael