PLEASE HELP!!! Montana sputtering

The problem IS the PCM!
I had a 2002 Grand Prix (uses the exact same PCM) with the same problem. I replaced coils, plugs, wires, intake gaskets, MAF, TPS, EGR crank angle sensor and cleaned every electrical connection in the engine compartment. The problem would go away and come back--early morning dew--when it rained and sometimes just intermittently.
Turns out it was the PCM. I took it out and took it apart and found it had some cold solder joints and was getting moisture on some contacts. After replacing the PCM with one from ebay the car ran like brand new!
Since the PCM is in the ugly black air filter box in the front of the engine compartment where heat and water can get at it--it's not really the best place to put it from an electronics reliability standpoint.

The only way you can eliminate the PCM as the cause it to replace it with a known good PCM.
 
Well when i was troubleshooting this weekend i took my squirt bottle and sprayed the coil/module and with a couple squirts i shut the engine off completely and it wouldn't crank until it dried. I did this a couple times and it was a very consistent problem.

I replaced the coil and module with a used one and then no matter how much water i sprayed on it i couldn't make it shut off any more.

But the owner said he cranked this morning and it did the same sputtering when he throttled it up. It didn't seem to do it at idle. But I think it may still be having the same problem. I think that we did fix a problem with the coil/module but we didn't fix the problems that we were trying to fix.

I am wondering about this PCM. Can i just get any used computer that will fit or do i have to get one that matches the vin#, or buy a used one and get it re flashed. I'm not sure for a Montana. My f250 required one to be looked up by the VIN# and my 89 chevy just interchanged with any other computer out of a chevy.
 
Well i tried a computer out of a chevy venture and the pontiac montan wouldn't even start. I could turn the key on and the accesories would work but as soon as I turned it to crank nothing happened.

Does anybody know where to get a computer from that will work in a 2001 Pontiac Montana.
 
I replacedmy computer and replaced the leaking fuel pressure Regulaterbut it is still sputtering until it finally shuts off. Please help anyone!!!
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Well have you checked plugs and wires ? How about map sensor ? I believe you can clean the map sensor ??? I guess I should of asked this question first : is the cel on ? Do you think it is fuel or spark? How about injectors maybe one is plugged or bad ?
 
Ever since the new computer the check engine light stays off. Haven't cleaned map sensor. I have changed spark plus and wires since I have started trouble shooting this problem so I don't believe it is that. But I'm open to any suggestions. So far its taking a lot of money and I have fixed little problems but not the one I'm most concerned with.(the sputtering only on the first start up of the day.) Runs great the rest of the day.
 
When on a cold start up it only happens ? Wondering if this happens on every start up or just on cold start ups ?Then how long before it runs normal ? Is it maybe 15 minutes maybe after t stat opens and engine is up to operating temp ? You said you replaced the coil pack and that seemed to help but underneath the coil pack is there a module that the coil pack plugs into ? Also that module might have a bunch of wires going to it also ,if so maybe that is cracked and when warmed up it kind of expands and makes better contact and when its cold it contracts and doesn't make good contact ??? Kind of weird just heard this problem on "Car Talk" last weekend .
 
New update. I cranked the van this morning and it idled ok. We drove it down the road and as long as we didnt push the accelerator pedal past about 1/2 inch it sped up slowly because it stayed under 2000 rpms but it seemed to drive fine. As soon as you push the pedal farther it started cutting out. It did this until the engine temp reached 185 degrees. After it warmed up it ran normal and great the rest of the day. I replaced the tps today and we will see in the morning if anything changes.

Still open to any ideas.
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Well I've worked on a van in limp mode before but this is nothing like that. Mainly because on really wet mornings it does all this cutting out just sitting still idling in the yard. Until it warms up then it too runs great after that. It will just smooth out itself.
 
I know this post is old but wanted to update the thread to maybe help someone else who is having this same issue.

Although all the above posts could also be a solution to this issue I have found the culprit that I had with this same exact issue.

I had no code showing up and the only way I found the problem was trying to change out just about everything under the hood.

The solution that fixed it was to replace the PVC breather hose.

Here is a link to the hose I replaced
http://www.am-autoparts.com/Pontiac...ium=comparisonshopping&utm_campaign=NexTagNew

It was actually cheaper at the local dealer and only cost 8.58 with tax and this corrected the issue instantly and only takes about 10 min to replace.

The actual problem with the old hose was that the grommet at the intake manifold had fallen off.

I hope this helps someone else and may help you to eliminate other issues.
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