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I’ve done this job. It’s a bugger because of the lack of space between the firewall and engine. Can’t get at it from the wheel well; knock sensor, but not the crank. There is a test for the crank sensor itself. You can unplug the harness at the ignition module to complete the test, but I cant say what the test itself is. An analogue ohmmeter while cranking the engine sounds familiar though. I have the dealer manuals so can take a look and see if it’s in there later. Best do this first to make sure your not wasting your time. If your car won’t start and you don’t have spark this could be your trouble. Bad ICMs seem to be intermittent. To change the sensor: - Get the car up nice and high on jack stands. You need to work from underneath with your feet out the front. - clean the bejesus out of the area before you start and shine up there with lots of light. - use a very long flat screw driver to carefully open the locking tab on the harness, don’t break the tab. While it’s open use a pair of very long locking pliers to jiggle the harness off. I’ll post a pic of the tool i used. I would not have been able to do this job without it. - I believe a 7mm (maybe an 8mm) bolt holds the sensor into the block. Use a ratcheting wrench and tape an extension to it. I think it worked better to tape on the inside half way down but might take a few try’s. - use the locking pliers to pull the sensor out, make sure the o-ring makes it in one piece. - like most jobs installation is the reverse of removal. Hardest part is getting the bolt back in. I fought with it for quite a while and ended up using a 1/8” piece of welding rod with 3/4” bent at a 90 on one end to line the sensor bolt hole up with the threads in the block. You just put the 90 in the crank bolt hole and spin the sensor until you feel the 90 drop into the threaded hole in the block. Rock it back and forth in your fingers to find best centre and the bolt should start first try. I fought getting the bolt in for a long time and had it land on my face a few times, wasn’t able to get it in without this little home made tool.

The crank sensor is not to far up the block when looking at it from the bottom. I’d think the exhaust manifold and down pipe would be completely in the way to go in from the top. Never tried so can’t say it wouldn’t work but I would be surprised if it was easier. I’d think its even tighter up top.

I've posted before about CPS sensors. Imho, *ONLY* use one that you buy, in person, from a local dealership! You've been warned. :) If people want to lay Russian Roulette, that is their choice. Iirc, even a "Standard (brand name)" from Rock Auto didn't last long. And, imho, the Standard (brand) is often better than the GM OEM stuff. Maybe it was one of the many counterfeits? Just my two cents. :) I've been happy with my local GM Dealer bought CPS now for many years. Before that, within ~6 months, I'd have the occasional "no start" pita issue that often happens with failing CPS sensors. Btw, I have TECH-II scanner (?possible clone?). So, I do a CPS calibrate when I change the sensors. Good Luck!

The dealer book is no help...

Anyone ever try to replace the LQ1 crank sensor from the top, with the cylinder head and intake manifold removed? I did a valve job on my '93 years ago, the knock sensor is real easy to get at, and I poked a block heater and alternator in at the same time because access is real good with the head gone. Didn't even look for the crank sensor; never occurred to me to dick with it. I still haven't gotten the '92 running; I bet it's been parked for six years or more. It's on the "List of Things to Do" for this summer--and part of that will be to valve-job the thing. So intake and exhaust manifolds will be gone, both heads and cam carriers removed, etc.

I’ve just posted the pics of the pliers above. Hope you can find em somewhere and hope you can get it done on your own. You’ll feel like a doctor doing surgery without being able to touch the piece you’re working on. Your hand won’t fit up there at all. A shop might tell you some nonsense on not wanting work on it as soon as they see in there. Not likely many mechanics have done this job lately. The book might even tell them to lower the cradle. Not necessary!