1989 tercel rough idle when cold

[ff123]

In the morning (we're getting down to the high 40's at night), my '89 Tercel (with 114kmiles on it) will run and idle very rough for about 5 minutes until it warms up and magically starts to run normally (it's as if a switch is turned on). I have a feedback carburetor system. When the car is cold and running badly, I have to step on the accelerator pedal a bit when it's idling or else it's likely to stall. Gas mileage seems very poor (22-23 mpg) if I have a high percentage of cold starts, but mostly highway driving gets me about 30 mpg.

Sometimes, there is a lot of white smoke when it starts from cold as well, but not always. I'm not sure if that's related or not.

Small stuff I've done to date:

1. new spark plugs, wires/cap
2. new air filter
3. oil & filter change (high mileage oil, 20/50)
4. new fuel filter
5. new pcv valve

Any ideas on what to try? I don't really want to put a whole lot of money into it because I'm going to get another car pretty soon. But if there's something simple and less than $100 I can try, I'd be willing.

[Doctor J]

Assuming that the car has 3E engine and cooling system is in the good condition (to rule out the head gasket), I would suggest to check the hose under the air cleaner that goes from the idle air bleed valve to the carburetor. If hose is cracked , or fell off, it could allow extra air to the carburetor when cold causing the rough idle. On several Tercels I replaced the defective valve itself.The valve is bolted to the air cleaner with two M5 screws Also check the electrical connections to it.

Some other helpful info is available on www.Autozone.com, also check the vacuum lines and solenoids.

[ff123]

Thanks for the reply. It is a 3E engine. The color of the oil is ok (it was amber and is becoming dark now). The old spark plugs looked ok when I replaced them. I will try looking at the hose you suggested (to the EBCV, right?)

Some more notes: I don't seem to have a problem when I start my car to go home from work. The differences from the morning cold start is that it's maybe 10 degrees warmer in the evening and it's not as humid in the parking lot.

When the engine is warm, I also sometimes have a hesitation/jerking which I mostly notice in 2nd/3rd gears (I have a manual). And I have what I think is backfiring when a let up the accelerator (mostly in 3rd/4th). Don't know if that's relevant, though. And I can live with those things. Having to warm up my car for 5 minutes is kind of annoying, though.

[Doctor J]

You may also check the EGR valve to make sure it is fully closing.

[ff123]

The hose from the EBCV loops around to the carburetor in two pieces, a straight part, and a loopy part with a plastic connector piece in between the two hoses. I was able to roll the straight piece around easily (I shouldn't be able to do that, right?) and I could see that it wasn't pushed up all the way on the connector. However, it wasn't like it was pulled off.

This morning I got a good cold start with no idle problem, and was able to get out of the car and see just water vapor coming out my exhaust. We'll see if I continue to get good cold starts throughout the week, but I'll still probably get a new straight piece of hose.

[ff123]

BTW, the hesitation and backfire is still there (I didn't really expect this to change), but I wonder if a new distributor rotor might help that? I only bought the cap and wires because I had broken the wires when I replaced the spark plugs.

[ivrunner]

Originally Posted by ff123

The hose from the EBCV loops around to the carburetor in two pieces, a straight part, and a loopy part with a plastic connector piece in between the two hoses. I was able to roll the straight piece around easily (I shouldn't be able to do that, right?) and I could see that it wasn't pushed up all the way on the connector. However, it wasn't like it was pulled off.

This morning I got a good cold start with no idle problem, and was able to get out of the car and see just water vapor coming out my exhaust. We'll see if I continue to get good cold starts throughout the week, but I'll still probably get a new straight piece of hose.

i have an 88 Tercel with the same engine, same carb, and same problem only i live in indiana and there are mornings it get 9 degrees. when this happens i takes a long time to warm up and run normal. before it idles normal it runs very rich, but like you said its like a switch turns on and it runs completly normal. is there any way you can get a picture of the hose you are talking about or maybe a little more info on what you did? Thanks

[ff123]

The EBCV is located just under the air filter on the passenger side, as in this picture:

http://www.autozone.com/az/cds/en_us...rInfoPages.htm

You can find the vacuum diagram for your car here:

http://www.autozone.com/az/cds/en_us...rInfoPages.htm

BTW, the next day after my good start, I got a bad start. But I hadn't replaced the hose yet, so the verdict's still out. I got a replacement piece yesterday (the old one had a crack in it and definitely needed to be replaced).

If I understand the way the feedback system works, it runs open (no closed feedback) until certain conditions are met. Apparently while it's running open, a variety of things can cause it to run badly.

[ivrunner]

where are you getting a new hose?

[ff123]

I had replaced the hose before my last post, but hadn't had time to see if it worked or not (it didn't). My cold starts were as bad as ever. But I did solve my problem -- I bought a 2000 Corolla VE to replace the Tercel!

[ivrunner]

Originally Posted by ff123

I had replaced the hose before my last post, but hadn't had time to see if it worked or not (it didn't). My cold starts were as bad as ever. But I did solve my problem -- I bought a 2000 Corolla VE to replace the Tercel!

HAHA. good choice. i wish i could do that. looks like i just may deal with it...its only winter for a few months out of the year right?