Stalling issue 90 3.1 SE

[Severoux]

Well I took a look at the Coolant Level Sensor in the Pontiac and it appears to have burst. Or something. Whatever it is, IMO it looks broken/bad. SO, What is the proper way to remove this part without breaking anything?

Checked the "write ups/how to's" section and did a forum search, but nothing came up...

[2stepperinaz]

First off, you need to start by draining your radiator. (2) Disconnect the pigtail (electrical) connector CAREFULLY as you dont want to break the clip. (3) Remove the wire spring clip by using either a small screwdriver, or a hooked pick (4) Carefully pry out (or twist back & forth) sensor, trying not to puncture or otherwise damage radiator (5) Clean/remove all traces of dried coolant and old O'ring (6) Lubricate O'ring (with patroleum jelly) that came with NEW sensor (7) Install new sensor by simply pushing onto radiator (no need to remove wire clip) (8) Re-connect sensor wire (9) Fill radiator and purge air from system --->VERY IMPORTANT STEP!

Your are done!

[Severoux]

Ok, hooked everything back up, disconnected the Coolant level sensor, then tried starting it. Idles at 3k. RE-did everything back to the way I had it befor, so that the idle would go down to 1500~. So that sensor was not the issue... I am so tired of chasing things around in this car...

[Severoux]

Any ideas from anyone? Anything at all?

[ibhuff]

im not very familiar with the 3.1 multi port, but i can tell you that my 3.1 sfi threw an iac code when my throttle body gasket was bad, basically its sucking air from somewhere other than through the filter. i would replace tb gasket. upper intake gasket, clean out egr inlet in upper intake with a wire brush while its off "mine was clogged completely with carbon" and make sure all your intake tubing is good and snug. then make sure all your vacuum is correct. if you need torque specs or vacuum diagrams or anything like that let me know and i can have them for you on tuesday when i have access to ondemand5 and alldata at school. i would definitely do this myself cuz im sure that a mechanic would charge a pretty penny for this job when you can do it yourself in about an hour for the price of 2 gaskets.

[Severoux]

I already replaced the IAC plate gasket, Throttle body gasket, EGR gaskets, Plenum gaskets... Checked and replaced almost all vac hoses...

[Severoux]

I have had an idea on something, and have tried to research it but I am un sure what it is that I am looking for exactly. When I plug in an IAC valve to the connector, and leave one hooked up to the car, I can see that the pintle "opens" when the car starts, and "closes" when the car is shut down. Now, the pintle only needs to be "open" during certain starts.. I.E. Cold starts ect. So when the pintle is not needed to be open, what it is that tells the ECM that it can "close" the pintle? I.E. on warm starts ect. I have replaced the Coolant temp sensor, but is there another sensor(s) that could be malfunctioning, telling the ECM that it needs that extra air still because it is registering cold? Engine/block temp sensor? I tried looking it up and pricing it on O'Reily.com but it is saying that the 1990 Grand Prix does not have one. But it also says that my car does not have a MAF sensor, when I know for a fact it does. I also cant find anything on this in my chilton for some reason... Thanks

[Severoux]

I fixed it! There is a sensor, the one that controls the temp gauge on the instrument cluster, it was out. There was also a small vacuum leak on the under side of the EGR valve adaptor plate. Used some Blue hi-temp gasket maker to seal up the EGR vac leak and un plugged the temp sensor and it runs great. My only issue now is... What is the exact name of that sensor that gives the temp reading on the instrument cluster? I cant find it's name... Thanks!