97 3.2 Rodeo Code P1509

I have a 97 Rodeo that has been having some issues for the past 2 weeks. I have had a CEL come on twice since this started and took it to get scanned today. It had a P1509 which is IAC Sensor High and a stored code of P0101 which is Mass Air. The weird thing is after its starts acting up I can reset the ECM and it runs fine for a day or 2. The IAC is 50 bucks or so, but I hate throwing money into parts that I'm not too sure will fix the issue at hand. The car will go through this scenario: Starts with a high idle (1500) then goes to a low idle(>500). After it does this it then will sputter while driving between 1500-2000 RPMs until I get past 2000. After it does that a while it goes into stalling anytime I let off of the gas completely while driving. Then it won't stay started unless I give it gas, but as soon as I let off it dies again. Then like I said if I reset the ECM it will run fine for a while before it goes through that scenario again. It has done this maybe half a dozen times in 2 weeks but have only gotten the code to come on twice. Does anyone have some legit info on this other than the obvious change the IAC valve. Thanks in advance.

PS: I have tried disconnecting the IAC and driving it when it runs fine, but eventually it goes back to the same scenario. To me this would rule out the IAC because it is no longer sending any info. Not sure??

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i don't know if it was this forum or another, but this *exact* same scenario was detailed, iirc, and it turned out to be the MAF sensor.

that would be the thing to do first. one trick i've seen mentioned is to give a rap with screwdriver and see if that affects a momentary change.

try using the search for this forum to see if you see the postings.

//bc

I took apart the MAF Sensor and one of the resistors had quite a bit of crud built up so I cleaned it off. Put it back on and ran good for a while, but same scenario came back. I have searched this forum for a good while and I can't find anything that really seems to help with this problem. What are some other forums that deal with these motors? Does anyone know how to check if the IAC Valve is functioning correctly? Anymore advice would be greatly appreciated. Thanks Ken

I took apart the MAF Sensor and one of the resistors had quite a bit of crud built up so I cleaned it off. Put it back on and ran good for a while, but same scenario came back. I....

then it does sound like you did find the problem. perhaps it didn't get thoroughly cleaned, and perhaps you need a new one. but if the initial cleaning solved the problem and the CEL indicates that's the problem, i'd say, that's the problem too. imo

have you taken another look at it?


//bc

It turned out to be a combination of the dirty mass air sensor and IAC valve. I cleaned the Mass air sensor with electrical cleaner and it got rid of the stalling between 1500-2000 RPMs. I also pulled the IAC valve and cleaned the plunger with some carb cleaner. It worked better but wuld still stick at a high idle occasionally. So I spent the 47 bucks put a new one in and haven't had a problem since. (KNOCK ON WOOD!) Anyways thought I'd let everyone know in case this comes up for someone else. Ken

Thanks!!