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SomethingWittyAsAUsername 12-18-2012 11:56 AM

New 91 keeps stalling...but only when cold
I just bought a 91 wagon to keep my 95 company....for only $300 :)

However, it won't idle at all when it's cold. It gets better as it warms up, and once it is at operating temp, it's perfect.

Any idea what I'm looking at?

whitetiger 12-18-2012 12:05 PM

IAC is prolly failing in the cold. you would have to confirm this though with diag tools.

mnstrmech 12-19-2012 08:16 AM

coolant temp sensors can cause this condition too... and these engines are common for bad coolant temp sensors

SomethingWittyAsAUsername 12-19-2012 09:59 AM

Thanks for the info! I hadn't thought of coolant temp. I know where the IAC valve is, and I'm going to take that off right now and make sure it's not clogged and can still move.

Other notes:
I don't get a check engine light.
Even when the car is warm, when I let the clutch out and the motor is above 2000 rpm, the revs drop to almost zero, but recover.

94legacy22 12-19-2012 11:49 AM

my coolant temp sensor went bad, and did the same thing. only the coolant fan would run on high till i cleared the code and replaced the sensor. once replaced and disconected the battery for 20 min the fan shut off and it runs great cold now. Now to locate a cheep Maf sensor that i need...

SomethingWittyAsAUsername 12-19-2012 12:44 PM

Would my temp gauge still work with a bad sensor? I only wonder since mine does

monkeyposeur 12-19-2012 05:29 PM

There are two coolant temp sensors. They are side by side on the coolant crossover pipe. One goes to the cluster gauge, and the other goes to the ecu.

94legacy22, there are a lot of junkyards out here. I could probably find you one if you don't have any luck.

SomethingWittyAsAUsername 12-19-2012 05:51 PM

So any idea which sensor goes to the ECU? And is the MAF an option?

monkeyposeur 12-19-2012 06:54 PM

1 Attachment(s)
I'm not 100% sure, but one sensor is labeled the water temp sensor, and the other is labeled water temp gauge. I would guess the water temp sensor goes to the ecu.

The MAF is standard on n/a first gens. Is that what you are asking? Or do mean a bad MAF may be your problem?

SomethingWittyAsAUsername 12-19-2012 07:57 PM

Thanks for the diag, but where exactly is that pipe? And I have two model numbers for temperature sensors. One is just a spade connector, while the other is a two prong electrical connector.

And can the MAF be a problem?

monkeyposeur 12-19-2012 09:14 PM

The water pipe is large and sits underneath the intake mani which is why you haven't noticed it before. The left side connects to the upper radiatator hose, follow that back and you will see it. The spade connector is temp sensor part 22630 AA040 or 22630 AA041. That is the part that will connect to your ecu. The other sensor is gauge sensor 21203 AA030. You want the spade connector.

If you want zip files of the factory service manual and/or complete parts catalog pm your email and I'll send them to you. They are very useful and informative.

The MAF can be a problem, but it probably isn't your problem. If it was your car would run like crap all the time or not at all.

SomethingWittyAsAUsername 12-19-2012 09:39 PM

Excellent! Thanks! I plane on taking the IACV off tomorrow and firing it cold. If I'm correct and that's the issue, won't it idle just fine?

And I hope it's that. IAC valves are really expensive :/

monkeyposeur 12-19-2012 09:49 PM

I don't know enough about the IAC valve to say. I know it sends higher rpms on a cold start. I don't know if it is a good idea or not to run the car with it off. I know that you would want a replacement gasket on hand if you decide to take it off. I would try cleaning it and then reinstalling it first.

05LGTLtd 12-20-2012 06:40 AM


Originally Posted by SomethingWittyAsAUsername (Post 4212561)
Thanks for the diag, but where exactly is that pipe? And I have two model numbers for temperature sensors. One is just a spade connector, while the other is a two prong electrical connector.

And can the MAF be a problem?

there happens to be nice picture in an active thread in this forum:

monkeyposeur 12-20-2012 06:29 PM

^That is on a 22T, not a 22E. The coolant temp sensors are in different locations depending on the model. On the 22T they are located above the knock sensor. On the 22E they are more to the left. The diagram I posted above is for a n/a 22E.

But it is a great pic of the water pipe. Thanks!

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