94 Camry, low initial cold idle

Hello,

Vehicle is a 4cyl auto, 156k miles.

Starting cold (stopped 8-12 hrs), ambient temp 15-40 or so degree's, the engine will initially idle at 800 RPM's for a few seconds, then increase to about 1100, and seems to drop more quickly than normal. going into gear makes the engine briefly stutter, and feel like it could stall but does not.

Idle when warm is smooth and stable, and I don't notice any drivability issues. If I start the vehicle after an hour or so wait in the same ambient temps, the idle immediately goes to what seems the normal

1100-1200 RPM range.

There is no MIL light or codes stored when scanned, wires/cap/plugs are OEM and have less than 40k miles, vac lines seem fine, and the TB and IAC valve are spotless, and have been very regularly cleaned for many years.

I appreciate your thoughts on this matter.

Thank you.

Reply to
platil
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All your idle numbers sound high, I idle at apx 600

Reply to
m Ransley

Sometimes you need to replace the IAC valve. The EGR port is close to the rear of the throttle body and can accumulate carbon in back where cleaning doesn't really reach it unless the TB is removed, plus there can be physical wear on the IAC valve. On my 1994 4 cyl. with 125,000 miles, I found a wear pattern on the . . . not sure what to call it . . . there's a small cylindrical drum that rotates to expose or cover a window port, and that drum mechanism had some light scratches on it. If you go by the Factory service manual, for IAC replacement, you'll be directed to the prior secton regarding TB removal, which also contains a section describing adjustment checks for the TPS and throttle positioner. On mine, both needed adjustment. Basically, the adjustment for TPS involves setting the first two electrical pins in the connector to break continuity for Idle at .024", with a vacuum applied to the throttle positioner diaphragm to pull it back out of the way of the throttle stop. There are some vacuum ports in the TB that also get cleaned - helpful generally in just off idle, but probably not directly related to cold start idle.

Reply to
Daniel

Thank you gents! Seems to be getting worse, especially when shifted into drive right after a cold start.... Almost wants to stall. Thanks again.

Reply to
platil

I had the same exact problem, except it came at 45k. It's a '96 camry dx 5-spd. IAC didn't do the trick so they ended up changing the whole throttle body assembly with a new IAC(it was under the extended warranty, what a deal that was). Anyway, the first attempt should be a new IAC, make sure it's the right one for your configuration and emmisions. I now have 226k on my camry, just recenly changed the timing belt, water pump, oil assembly, and 2 axles, around grand, but I had to give it a shot, even at 225, I love that car. I am still on my second set of brakes, but I don't think for long...and wonder how much more Iiiiii'll getsuckered into until i throw in thetoel and buy a 5-sp Solara.

Reply to
steve-o

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