Swapped air filter now 96 SC Riv wont start

I've checked all of the vacuum and fuel lines. Car cranks, but runs violently for 5 or so seconds then shuts itself off. Any ideas?

Did you accidentally unplug or break the IAT sensor? It's mounted on\in the air box.

I don't believe I did. I've replied a few times on the mobile format and they aren't showing up for some reason.

I removed the one visible sensor plug on the left side of the air filter lid that connects to the actual resonator tube. I made sure that the wires were not broken, and plugged back in when I was done. I was under the assumption that this was the MAF sensor. Do you have an exact location of the IAT sensor? The only other thing I can think of, the connection ring from the resonator tube to the intake manifold was broken and duct taped prior to me purchasing the vehicle. I made sure to put it back on to the best of my ability and then I re-duct taped it to try and achieve the same seal I had before the air filter swap. Those resonator tubes are as hard to find as fender trim. I can find it for the 95 model, but that's it, and they are completely different.

The MAF plug is the wide one on top of the Throttle Body. The IAT sensor is a little 2-wire sensor that is mounted in the air box. If your intake tube has a hole in it for an IAT, then it is the wrong tube for the car. This may also be why it's duct taped . The only other hole in the intake tube might be on the bottom side IF the silencer fell off. Then there would be a 2" diameter hole in the bottom of the intake tube.

Duct tape......go to a junk yard and find a tube. Unfortunately, I don't have a spare for you. Contact a GM dealer and see if they can't locate one for you. You might just have a GIANT air leak. That 3800 will never run correctly with a leaking intake tube on it.

I think we may be misunderstanding. Ok, it was the IAT sensor plug then that I removed. I was thinking that was the MAF sensor (can't trust diagram images on Google). So there is no hole per se. The issue with the duct tape is that the rubber ring that goes around the intake manifold connection is ripped. It's not that there is a huge gaping hole. The car has run fine for a year since I bought it with the duct tape there the whole time. Also, I checked the wires on the IAT sensor, and they do not appear to be broken.

Also, none of the junk yards near me have the tube. Nor do my local GM dealers. I've been up since 4 this morning when I was supposed to leave for work and have called everyone in town already.

Did you squash the honeycomb inside the TB?

TB?  Sorry, I know just enough about this stuff to be dangerous.  But I'm learning.  I've already done a ton of work on the car myself, but every new thing is a from scratch learning experience.

Edit- did you mean throttle body? And honeycomb, I'm assuming the screen that is on the engine side where the tube connects? If so, I was very careful not to touch that at all. Just unwrapped the duct tape, separated the two pieces of the outer rubber ring and pulled the whole tube away from the connection. Then I did the exact opposite to put it back on. The parts houses here are looking for the tube but it has been discontinued from GM so finding one is probably not going to happen. Is there some sort of rubber epoxy I can use that would withstand engine temps? Or anything else you would recommend until I can track one down? Its unfortunately my project car AND my daily driver.

I'm not entirely convinced that the tube is your problem. Try unplugging that IAT sensor and see if it starts and runs. If it's unplugged, the PCM will think it's -40*F outside. On the opposite end of that, if the circuits are shorted together (bad sensor/wiring), the PCM will think it's about 180*F, and take away fuel. The 3800 is quite dependent on that sensor to run properly.

Concerning the sensor - unplug it and test it with a digital ohmmeter, or a FETVOM if analog. It's just a thermistor. If it is open (apparently infinite resistance) or shorted (apparently no resistance) you need to know, that's a major problem. It is not often, but not unheard of, for the IAT to fail. I do not remember the specs for this thermistor but they may be elsewhere on this site. Typical base resistance (resistance at 25 degrees C) will be so-many-thousand ohms. The link shows a guide from Autozone giving a table of values for a typical GM IAT.

https://www.autozone.com/repairguides/GM-Century-Lumina-Grand-Prix-Intrigue-1997-2000/ELECTRONIC-ENGINE-CONTROLS/Intake-Air-Temperature-IAT-Sensor/_/P-0900c15280217ce3


As for the air hose: Consider getting another intake hose off another GM car that's using the 3800 engine (199x-2004 LeSabre or Park Avenue or such, there were a bunch) on which the Throttle Body (TB) end with that fat rubber ring fits your TB.   Probably find more than one such at a pick-n-pull.

Then -- you'll use the end closest to the TB on the picked hose.  Make sure it fits your TB (it should) then figure out where to cut it such that it can be spliced and glued and/or clamped onto your current hose. To make a splice you could cut a strip of steel or aluminum to make a loop that will just fit inside the air hoses at the splice, then secure them with appropriate cement and screw-on hose band clamps.

Albertj

Well, I feel like an idiot. The air filter wasn't all the way seated which caused the housing lid to apparently not seat and create a seal. Re-did everything and now it runs better than it did yesterday before I swapped the filter.

Cheers guys. Thanks for the help.

ABerkman wrote:

Well, I feel like an idiot. The air filter wasn't all the way seated which caused the housing lid to apparently not seat and create a seal.

Yep. That'll do it

ABerkman wrote:

Well, I feel like an idiot. The air filter wasn't all the way seated which caused the housing lid to apparently not seat and create a seal.  Re-did everything and now it runs better than it did yesterday before I swapped the filter.

Cheers guys. Thanks for the help.

Great progress! but you've still got that rubber ring issue.

Yeah, I think I have that one figured out. Think next time I need to swap the air filter, I'm just going to swap out the entire air cleaner system for a cold air intake. It's going to cost me about the same in the long run... and I wont have to worry about spliced rubber falling apart and leaving me stranded. I did epoxy the existing tube and then put almost a whole roll of duct tape around it. If it will make it 3 or 6 months like that I should be good to go.

ABerkman wrote:

Yeah, I think I have that one figured out.  Think next time I need to swap the air filter, I'm just going to swap out the entire air cleaner system for a cold air intake.  It's going to cost me about the same in the long run... and I wont have to worry about spliced rubber falling apart and leaving me stranded.  I did epoxy the existing tube and then put almost a whole roll of duct tape around it.  If it will make it 3 or 6 months like that I should be good to go.

Hmmm.

You might not wanna do this but a splice in the tube after the rubber ring and before the other nonsense would work - might have to support it some how.

I kinda like your approach to install a CAI - the setup as it is, *is* a CAI (pulls air from the fender well not from under the hood) but you've got all that excitement with the hose to deal with. Installing a new CAI setup isn't all that costly and will look & act somewhat cleaner. Some CAI setups change air flow enough to "lie" to the MAF so beware...

While you are at it you might want to get a throttle body gasket so you can pull the TB and clean the backside of the throttle body housing/air passages, and the IAC circuit passages too.

Albertj