Corolla 88 with 4A-F problem - Toyota Nation Forum : Toyota Car and Truck Forums

george · 03-14-2004, 09:58 PM

I have Corolla 88 with 4A-F engine. Car was running perfect but something happened a few weeks ago: when I start cold engine, first it maintains at low rpm but after 2-3 minutes running goes on very high rpm so I am afraid engine could broke. Then I start driving on low speed and in a few minutes (5-10) engine rpm became normal. Any advice appreciated.

Flashmn · 03-15-2004, 01:25 AM

Sounds like a glitch in the cold-start circuit.

toyotaspeed90 · 03-15-2004, 01:55 AM

if need be... i have a spare 4a-fe cold start sensor i'm selling for $10US + shipping... let me know if you need it:

toyotaspeed90@hotmail.com

|PuNiSh3R| · 03-15-2004, 02:24 AM

No biggie, see when u cold-start the engine the cold start circuit causes the car to slowly idle up higher and higher until a certain temp is reached and then it'll go down to normal idle speed.. Nothing with the engine is broke and it won't break the engine

george · 03-15-2004, 04:51 PM

First of all thank you all for the answers. I am going to replace that cold start sensor, where is it located ?

|PuNiSh3R| · 03-15-2004, 05:33 PM

george, take the car to an auto garage it would be your best bet.

george · 03-15-2004, 05:47 PM

I did this, they told me to replace carburetor... Can do something by myself, love my Corolla. Replaced fuel filter, master and release clutch cylinder. Can do much more .

|PuNiSh3R| · 03-15-2004, 06:13 PM

Go to a toyota dealer

george · 03-15-2004, 06:28 PM

to replace sensor ? It will cost me more then I can get for my Corolla.
Are you working at Toyota dealer ?

***REN69*** · 03-15-2004, 10:03 PM

There's nothing wrong with the car, its called "CHOKE CONTROL" and it helps the car warm up faster in the winter.. what it does ( just like punisher said) it revs up the engine higher and higher until a HOT temperature is reached then it will shut down and let the engine rev at normal RPM and yes.. it will take 5-10 mins and sometimes even longer.
Some cars have manual choke controls.. which means you would have to pull a lever for the motor to do this. I used to have this on my 87 Civic. It will not break the engine. (God knows how many times I've revved up my motor past the 7200 RPM redline.. actually I do too.. 3 times

and my car still works.. 300,000km

)

|PuNiSh3R| · 03-16-2004, 02:49 PM

Ran my 4AF to 7,300 in second gear yesterday when I slapped sticked it on the high way out of O/D down to 2nd at 80mph.. and I normally run first to 7K when I slap stick.. lol. Poor pig.. To bad my 4af is like shot or something .. won't know what is wrong till I tear it down after I put the 7AFE in.

staticpage89sr5 · 03-20-2004, 05:42 AM

My 89 4a-f idles up like that but some times when it hits 2000-2500rpms when it’s warming up it like stalls then revs back to 2500 and I will do this for some times 5 10 min like some ones revving it up then letting off then revving it up letting off also it will do this to me wile im driving seems to do this only at 2000-2500rpms and one day at 5500rpm it gets kind of out of hand when im on the high way in overdrive it’s a 4 speed AT any one know what’s going on. Thanks. This forum is the best place for info in my car I have found thanks

FCON_VPRO · 03-20-2004, 05:58 AM

I agree with the others that theres nothing wrong with your car. I also have a 4AF engine and when the automatic choke is engaged it idles at about 2000rpm and sometimes go's to 2500rpm but thats very rare. What your car is doing is normal to me and my car does exactly the same and I havent found any problems yet.

|PuNiSh3R| · 03-20-2004, 03:10 PM

Infact it says on the sticker under the hood for cold idle up "3000RPM max"