Update on my 81 745i, still misfires...

[Reubenix]

Its been a year since I last posted and have been working on the 745i trying to stop a misfire. So far I have replaced the coolant temp sensor, oil pressure sensor, replaced vacuum lines, smoke tested the car, done a valve adjustment, cleaned the injectors, replaced the cap, rotor, and wires, checked the afm, have done a leak down test, and set the timing.
When I have done a compression test the results never seem right getting 30psi in every cylinder so I did a leakage test instead and each cylinder showed about a 10% loss. Running there is a constant misfire at idle and anywhere else in the rpm range; the engine runs at 7 psi of vacuum and my boost gauge shows that only 6psi of boost is building of the 9 that should be there.
I have gotten a bit tired of trying to find the cause of the misfire. I have fixed several vacuum leaks to no avail. Im looking for some more incite, could it still vacuum leak? I tested the afm and it seemed ok as far as I could tell. The timing was set, still may not be perfect but the misfire doesn't seem to go away while setting the timing regardless. Im on to a couple of other things that I think could maybe be the problem. There is a small oil leak that I think is coming fromm the oil pan that could be leaking vacuum? Also maybe the ecu is bad but I don't think that is a very common problem, is it? Other than that maybe I did a test wrong and wrongfully eliminated something as the cause of the problem.
Other than constant diagnosing of the misfire, though I'd just share some more updated pictures and information on my 745i.
Some better pictures, rims have since been changed to more period and less 90's rims, don't have a completely up to date picture but those are the that I have put. Rims I put are still 15'' anything bigger doesn't fit with the car being lowered as it is.

rims IMG_1987.JPGIMG_0994.jpg
I
Original recaros
IMG_0991.jpgIMG_0992.jpgIMG_0997.jpg

I also have all the records of this car going back to 1982 when it was imported to Denver Colorado. Have the receipt for the racing dynamics body kit; the wing is not the best, made by zender, but its staying. The trunk and roof of the car have also since been painted, not perfect but much better than how it was. The receipts also show the devaluing of the car, bought in 1982 for around 60,000 , sold for 30,000 in the 90's and I bought it in the 2010's for about 3,000. Im the third owner of the car that has driven it.
Also just some somewhat interesting information, at a car show someone said the knew a person who helped develop the 745, said the m106 was superior over my engine , and that they made all of them automatic because it was faster than the manual due to faster shifting. Not sure if I believe that considering mine has a 3 speed so your going 35 by the time there's any boost.

Any help on getting it to run right would be nice, Im getting stuck on thinking of more things that could cause the problem. Thanks.

[Hit Man X]

What is the exact build date of this car? What ECU (should be -124 early with brown label or -127 late with yellow label)?



What plugs and wires as well as plug routing (1/5/3/6/2/4 is firing order) in relation to rotor rotation? Which CTS? What 'vacuum lines' did you replace and how are the small vacuum lines routed? Cleaned injectors how and what part number on them? How did you set the timing and to what? What AFM is on the car? What is your rail fuel pressure... you should have a 2.5 bar reg so look for about 36psi at the rail.

30psi a cylinder? You are preforming the test incorrectly or have a bad gauge...or both. The 7:1 motor should be 120-130psi area, the mid gen Ljet at 7.5:1 should be a tad higher probably 125-135psi area. 8:1 140-150psi. It is just not going to run period, at 30psi a hole.

You cannot make 7psi of vacuum. Do you mean 7 INCHES of vacuum? If so, you are about 10" short of a sealed up M30 (17" at 850rpm with about 14:1 on the wideband is spec). Have you tried another gauge to verify? What gauge are you using for your current readings?

9psi on an Ljet? Try 0.7 bar or 10.15psi is stock. Forget making that now anyway as your car runs like shit.

Buy an AEM wideband with gauge. 30-4110 model.



Get back to me with detailed answers and pictures to ALL of my questions and I can give you more information.