Yes, you can damage the cam or the pump if the cam position is wrong. It must be at the lowest position and in yes, you will need to manually turn the crankshaft pulley bolt to reposition, do this slowly.

I didn’t have the GM go no go gauge they sell for $40-$60 so I took my old fuel pump and used it as my gauge . Out of position (lobe high) cam seems like the pump was about a 1/4” or maybe an 1/8” from being flush. I held it with gentle pressure while my brother slowly turned the crankshaft. After a few pulls the old pump slid down to be seated. I had him turn just a bump more and tried the new one. It went on nicely.

I didn’t remove some other covers and components to make it easier to loosen and tighten the lower bolt. It’s tough to get that one out but if you’re not wanting to take the water ducts apart and replace those gaskets you can do that too but I’m stubborn and did it with wobbling sockets and extensions.
You’re better off using some wobble joints and a flexible adapter to get down and across to access the bottom screw.
If that doesn’t work for you the you’ll need to remove some water jacket components on the back of the motor below where the fuel pump is but more to the center and replace any gaskets that were opened.

Also! It’s critical to replace the high pressure lines. They’re made to be used once only. No gaskets or whatever.
The high pressure lines can run up over 5-6000psi. You could easily burn your car to the axles if that failed and is ignited.

I found out I had a bad HP fuel pump.
I started getting an unsteady idle, bad acceleration, hesitation on acceleration would some cause the engine to stall plus bad mileage and dieseling.
You don’t want these motor dieseling that can really screw up your timing chains.

I connected a OBD2 and saw that my short term fuel Ratios were jacked up bad. I was getting 20-38% when the should be around 1-5%. On each bank. And when it was acting up I never got a code or warning except for bizarre traction control codes, TPS errors all kinds of crap like that. If I cranked my SRX and let it idle a minute to warm up some bogus error would usually pop up before I took the car out of Park.

all that crap went away after changing the fuel pump and of course changing the engine oil due to gasoline contamination, see below.
The reason it jacks with your short term fuel
Ratios is because the whole block has this gasoline vapor in it and I think the MAF sensor or some other intake sensor tells the computer we’re Rich on the mixture and between that and the O2 sensors it’s mayhem and it starves the engine so to add to misery the gasoline tainted engine oil cause the car to run lean as hell but still get terrible mileage. O2 sensors should be fine because they’re doing what they’re designed to do.

Also, failed to mention a dead giveaway your high pressure fuel pump is bad is to check you engine oil dipstick.
IF YOU SMELL GASOLINE, IN YOUR ENGINE OIL, CHANGE YOUR FUEL PUMP ASAP.
The gasoline thins and dilutes your engine oil and can cause bearing damage and much more like damaging seals.

I think I replaced my HPFP and fuel lines for about $150 and an afternoon. I doubt a dealer would do it for under a grand.

This was in 2022
Good luck and I’ll be happy to answer any questions, that fuel pump was tough for me last year. I couldn’t find anything on Cadillacs. I actually found exactly what I needed on an Equinox forum.
Cheers!
Ray

 

So I changed my hpfp yesterday and now the car will crank but cuts off. Someone told me there is air in the fuel system. What can I do about this?

 

Did you replace the lines also, as mentioned in the above post?

 

Yes. My fuel pump isn't priming. It is so confusing because it will crank and run fine. Then after it warms up it just stalls like it's running out of gas and it cuts off. I'll sit a minute then it cranks back up. And sometimes if I don't get above 2500 rmp sometimes it will run for a minute