2000 bmw 528i issues after engine rebuild

[AwkwardNoob44]

Okay so I just finished rebuilding my 2000 bmw 528i engine and this was my first time doing this so please bare with me as everything I know is self taught. I bought the car with a blown head gasket and ended up replacing the block with a remanufactured block and head with new gaskets all the way through both. After getting everything put back together I started it up and the engine is chugging and won't Rev higher than 1200rpm. I tested for vacuum leaks using starter fluid around the intake boot and pulled the o2 sensors from the exhaust manifold to test for back pressure and found no obvious issues. The only European code reader I can find is the little 2 digit handheld black one which Gave me the codes for the torque converter, the front o2 sensor, and the throttle body. I also didn't realize until after I started the engine that I did the torque sequence for the iron block which is 22lbs 90° 90° instead of 30lbs 90° 90° is their an extra torque sequence I can add or an over lb rating or do I need to start over with new bolts. Any help or information you guys can give me to help me get this running right would be great thank you.

[AwkwardNoob44]

Not sure if this helps or not

[E39MGirl]

It's difficult to know where to start here because there are so many unknowns, but you really need to run a BMW specific diagnostic program across your car to see what fault codes have been set. The code reader you have isn't going to give enough information to help diagnose any issues reliably and you could spend a lot of time chasing ghosts. Most people will be hesitant to dive in without knowing what the BMW specific codes are. If you have a look at BMW Dirtracer's reply to the "Help reading/resetting traction control light 540i" thread you will find a good list of places to start.

Starter fluid is not a reliable way to check for vacuum leaks on engines like these (even more so if they aren't running right), and neither is trying to get a sense of the exhaust back pressure by pulling an O2 sensor. Get one of the solutions that are mentioned in the other post and then post your results so we have a better idea of where to start.

As for the head bolts, you are stuck with new bolts - or leaving it as is and hoping it is torqued down enough. You might be able to replace them without breaking the head to block seal by removing the coolant cap (cold, obviously) and backing the bolts out 10 degrees at a time in the same sequence you torqued them, until the first in sequence just starts to feel a bit easier to move. Once you get to that point remove the first bolt in sequence completely (leaving all the others in place) and replace it with the new bolt and torque it correctly to the first stage. Do the same with the others (in the correct sequence) until all are torqued to the base torque and then do your 90 + 90. If you are lucky this will work and prevent any leaks. The only other option is to pull the head and do the head gasket and bolts again. It's up to you. I wouldn't do any of this until you have an idea what codes are present though, as there may be other work required.

[AwkwardNoob44]

Thank you for the advice I already have new bolts coming and turns out I made the mistake of not properly twisting the throttle body plug all the way in. I will post an update of my results. Also thank you for the head bolt advice I would have pulled them all at once and restarted the torque sequence.

[E39MGirl]

I made the mistake of not properly twisting the throttle body plug all the way in.

If you did all of that work and your only mistakes were forgetting to completely insert one plug, and the head bolt torque, then you did very well indeed.

As I said there are no guarantees with the headbolt method I described, but it will massively reduce the likelihood of developing a leak compared with removing them all completely. Just make sure you mark each one when replaced so you don't lose track of where you are with things if you get interrupted for some reason.

[AwkwardNoob44]

Okay so I got the throttle hooked up properly and I'm left with one code p1765 can throttle valve; and I have the eml light and the transmission gear. I'm still waiting on my new head bolts. Is this still a throttle related code or transmission related. I'm getting mixed results from Google. Is this a bmw specific code that I need to have read by bmw?

Also it's automatic transmission if that helps any.

[AwkwardNoob44]

I cleared the last code with a bmw specific code reader and the code stayed away this time and the car is running almost perfect besides a couple miss fire codes I'm going to fix the head bolt torque and then see if fresh gas and driving it will make the codes go away.
Note: this engine rebuild has been a 7 month project so the gas is about 8 months old because the previous owner let it sit for awhile before he would see it to me.