Hello Yodatech people!
I bought a non running 1990 V6 Camry last month. Beautiful shiny black car, with a Landau top. Got it running with a new fuel tank, pump and filter. It ran so smooth, I was happy.
I had an intermittent engine light, and that's where the problem started. On this obd1 system, one has to use a jumper wire to retrieve the codes. After doing that, my car had a horrible idle surge. All the advice I asked pointed to vacuum leak. Well I regasketed everything from the intake up, not finding any hoses that leaked. Now I have no engine light, no surge, but the idle is at 2500 to 3000 rpm in park! and in drive it runs no lower than 1300 rpm without giving it gas. I literally had to use the brake test driving thru a school zone, because it will roll along at 30 to 35 mph! with my foot off the gas. Help! It ran great!

 

Hello,

A couple things to check:
Is the throttle plate closing all the way? When you re-assembled, did you adjust the throttle cable- is there any slack in the cable?
Did you check the idle air screw (on the throttle body)? Tighten to lower idle, loosen to raise it. do it in 1/2 turn increments.
Throttle body runs coolant through it, did you bleed the cooling system as well after reassembly?

 

Thank you for the info! I assumed repeated re starting and topping off coolant would be sufficient. Is there a specific bleeding procedure I'm unaware of? Cables seem right, with minimal slack. They went back on exactly how they came off, without adjustment. Nothing was done to the car, went from running perfectly smooth to horrible on the same day. All I did was check for codes , jumping the two terminals on the OBD1 connector. I had an intermittent engine light. I replaced a broken temp sensor, and the engine light is off. After that the car idled very high, then started surging. Not finding any suspected vacuum leaks, I regasketed everything. Also cleaned idle valve and throttle body. Now car idles at 2500 to 3000 rpm. I ordered a new used idle valve. New new ones are priced prohibitively.
One more question: as a test of the idle valve , I ran the car with it connected, and then with it unplugged. My assumption was, if its working, the idle should be different. Is that correct? There was no change in idle with the iacv unplugged.

 

Finally fixed! It took me long enough! But I'm happy to say that my 1990 Camry runs right again! On a hunch, I ordered a used computer ( ECU / PCM ), and replacing that did the trick! Re-gasketing to eliminate vacuum leaks did nothing. Cleaning, and swapping out idle valve, and throttle body did nothing. Changed the ecu, and it immediately idles beautifully.
Thank you!
End of story!

 

I am glad you got your car going again.

Thanks for posting the fix!