(1994 toyota previa - 2.4L DOHC)

This toyota was sitting up for months after it overheated and blew the head gasket. The head was given a valve job and reinstalled.
The van idles/drives GOOD when warm, but idles very rough and dies when cold.
After it warms the engine light comes on. (OBD 1)
Spark plugs and wires have been replaced.
Would antifreeze in the exhaust ruin the O2 sensors and cause this problem?
I am afraid it is off timing.
Any suggestions?

chakarnis

Yeah...it's a Previa. (Toyota outta be ashamed of themselves). Call a dealer. Explain the situation and they can probably give you an idea of what you're dealing with then ask them to transfer you over to used car sales.

kitch428

Wow! Most of these previa owners have gotten hundreds of thousands of miles out of them and love them to death!
many are still going strong. Anyway hippie, remove the passenger front seat and engine cover under the carpet. What we're looking for is the EFI coolant temp sensor. (ECT) i would replace that with a dealer part and go from there. It has a green connector and it sits just forward of the valve cover.

Keyword: "Runs good when warm" stay away from timing for now. We'll deal with the o2 sensors later also.

Also, you could flip up the drivers seat, look for the diagnostic connector, flip it open, jump termanals E1 and TE1 with a paper clip, turn on the key with engine off, and give me the number of blinks the check engine light flashes.
Hint: 25&26 are the o2 sensors. Rich/lean.

Edit: FYI, hippie PM'd me with codes 22 & 52. Coolant temp sensor and knock sensor codes.
After overheating and headgasket failures, these sensors are prone to fail.

Hippiefeet

In respomse to kitch428 :
Thanks alot, I will get back with you. =)

Hippiefeet

I replaced the efi temp sensor and with good results. The 22 code is gone.

Unfortunately the engine is still acting the same and the 52 code is still showing.