The complete repair, rebuild, repaint, and v8 swap of my early model sedan

[aaron.j]

Have you verified correct engine timing? Mechanical and the position of the trigger wheel

[JGood]

Plugs look fine.

I'm getting o2 sensor 1 & 2, and Lambda control 1 & 2 codes with the O2 sensors plugged in, which is when it stalls. Without them plugged in, no stalling and no codes. I have a known good used set, and a brand new set, no change between the two. And they aren't plugged into the wrong sides.

The engine was pulled out of a running 740i, and the timing was never touched.

The harness is good, I verified continuity and voltage across the DME end and the connectors.

[aaron.j]

Haven't heard from you. You did say you checked the intake manifold system with a smoke machine correct?

[JGood]

Yep, vacuum test showed 15 HG/in at idle. Did a smoke test, the CCV was barely puffing smoke so I replaced it and retested. No smoke from anywhere now.

[JGood]

Still working out the bugs. Haven't made any progress on the stalling/backfiring issue.

New issues are extremely violent shuddering of the clutch during release in 1st & reverse, and a loud clunk in the right front suspension. Everything in the suspension seems tight, no loose nuts/bolts, no bad ball joints, strut collar nut is tight, coilover setup is fine, camber plates are fine, swaybar bushings and links are good. As for the clutch, Centerforce doesn't believe there is any issue, I may have to pull it out and send it back for inspection this winter (if it makes it til then... the shuddering is getting worse by the day). I actually wouldn't mind if it would just break, so I would know what is wrong and can fix it! This setup isn't exactly 'proven' yet. AFAIK Bruce is the only other one running this m52 clutch setup, since he's the one who discovered it, and I'm not sure that he has as many miles on his car as I do.

But, I've put probably 2k miles on the car so far, and it's blast to drive! I'm already used to the power and want more. I may end up with a m60b44 hybrid build like Garey, or maybe go with a s/c.


Here's a video for those that haven't seen it:

https://vimeo.com/48686622

[Jean]

SC it :)

[bmwmech1]

Justin, just an FYI about Bruce's car... it's been tracked for 2 seasons now with the same clutch and AFAIK, he's had no issues. Maybe yours is an isolated incident or another component causing the issue... dunno. Mine works fine... so far, lol! Of course I have about 100 feet on mine, so a ways to go to get to your mileage numbers, haha...

Garey

[JGood]

Yeah, I'm thinking the combo of parts is good, just something wrong with my car like usual haha. I didn't know how many times Bruce had been on the track, but a 2 full seasons should be plenty to be assured the clutch is good.

[Jean]

Yeah maybe Bruce can report back on this, 2 full seasons is a good stress test!

[Will_NZ]

Have just spent the morning reading this, inspiring work on the body! If I had to do that much work on the body before starting the V8 install, I would not have started!!

Just a comment, my V8 started doing exactly what yours is doing with stalling, down on power in the lower RPM, backfiring etc. I tracked it down to the MAF eventually, now runs perfect again.

Mine does not have O2 sensors, motor came from a 1990 E32 which was not required to have them fitted in New Zealand at that time. I do know the O2 sensors can cause similar problems though, I also have a M52B28 equipped e30 vert which had an O2 sensor go belly up, with very similar results, so I would not rule them out.

Hope you get it sorted so you can enjoy the car the way it should be enjoyed... sideways!!

[JGood]

Have just spent the morning reading this, inspiring work on the body! If I had to do that much work on the body before starting the V8 install, I would not have started!!

Just a comment, my V8 started doing exactly what yours is doing with stalling, down on power in the lower RPM, backfiring etc. I tracked it down to the MAF eventually, now runs perfect again.

Mine does not have O2 sensors, motor came from a 1990 E32 which was not required to have them fitted in New Zealand at that time. I do know the O2 sensors can cause similar problems though, I also have a M52B28 equipped e30 vert which had an O2 sensor go belly up, with very similar results, so I would not rule them out.

Hope you get it sorted so you can enjoy the car the way it should be enjoyed... sideways!!

Thank you!

Funny you mention the MAF. I'm starting to lean back towards that as a possibility, and am on the hunt to borrow one from someone to give it a shot before buying a new one. It's not down on power though, which is why I'm not really getting my hopes up that it's a MAF issue.

The o2 sensors are new, and I also tried a known good used set. But, the problem of backfiring and jerky throttle exists when they are unplugged anyway, so they are not the main issue.

Yes, the car is much more fun when sideways

[Will_NZ]

When I say down on power, it was just at lower rpm when it would just gag, once the revs got up a bit, it would be back to normal.

I am running a 2.93 LSD, makes pulling off much more manageable!

[Jean]

I thought you rulled out the MAF from another car? Might worth another shot!

[LJ851]

Typically fuel injection maps ignore most inputs during full throttle events, a fixed set of parameters is followed with coolant temp, air temp and pressure being corrected for. Part throttle is where the maps get interactive and complex.

[JGood]

Well, since I'm going to be tearing the car down this winter to redo stuff that I rushed through to get ready for Bimmerfest (mainly the exhaust and a lot of brackets throughout the chassis), I decided it was time to get my own welder. I ran over to Eastwood on my lunch break the other day and picked up this guy.





MIG 175 (220v), spool gun, cart, regulator, etc... Got it all 1/2 off as an open box deal, but it's brand new. They had the TIG 200 welder as an open box deal as well for over 1/2 off, but I figured I'll just start with this for now.