M2 madness

[M3M3]

thanks for offer...maybe. checking locally. may send mine down to http://bimmerecu.com/ in florida. probably would not hurt to have it fully tested anyway before further mods and new chip. it is a 25year old piece of electronics that has been in and out of at least three cars...

found the resistance value for the ATS....2.5k ohm at 20c. mine is in that ballpark.

[ray_]

A post from S14power fyi, in case you've not read it...

"Rich running traced to A/N air temp plug

For reference to anyone having unexplained rich running, check all your plugs - nothing goes wrong by itself!

For the last few days the car was running very rich and I couldn't work out why. Light cruise was 13.2 AFR and not stable, when it should have been 14.7 (I know my car). Cold start showed 'Rich' on my Techedge WB02 gauge (never does that) and during light acceleration AFR's were down to 11.8 to 12.4. Something was very wrong.

First thought Baro sensor (disconnected that, no difference), then blue DME coolant sensor (disconnect, revs' rose so ok), ICV ok, cap and rotor arm ok, fuel pressure ok and stable. So it had to be something else causing rich running - too much fuel or unburned fuel (poor spark?) in exhaust pipe. I traced the fault to a 2 pin plug on the A/N harness where one of the female pins had been pushed back into the plug which connects to the Air intake sensor. I pushed it back, it clicked into position and the engine runs perfect again.

I cleaned the car the other day and cleaned the engine bay too, lifting all the wiring harnesses to put some polish on the paint (its good to be thorough once in a while...) In doing so I must have pulled the A/N harness where it goes to temp sensor on the front snorkel as I've just discovered one of the pins was pulled back through the plug and making a poor connection to the sensor. My fault entirely.

Hope this helps someone.

Cheers,

Dave."

[M3M3]

thanks...had that thread saved...:-)

i did pull the connector, checked the pins and checked the connectivity from that connector, to the harness connector, and to the ECU.

the thing starts, then you can watch the AFR going down and the AN trying desparately to compensate by trimming fuel until it hits its compensation limit. AFR then drops below 10 and car stalls. messing with the map did not have enough scope to fix.

something is telling the injectors to keep dumping fuel into the intake.

have a long email exhange ongoing with John at MAXX trying to narrow down the issue.

[M3M3]

finally got back to the M2 after e30 and lift install distraction...

ECU is at Programma for repair, so I started to take the Diff apart to fix the slop in output shaft.

feels like the left output bearing is a tad worn. will need to order up some new bearings and try to figure out how to get the inner races off the LSD spool.

to save someone else a search, i found this good "how to" on 320is diff rebuild on bimmerforums.

http://forums.bimmerforums.com/forum/showthread.php?t=1592551&highlight=320+diff+rebuild

I will save you the post Ray...or i could just get a new 4.10.....;-)

[ray_]

Whaaat? ;-)

I think my 02 sensor is lagging. Ordered a new one.

I may re-flow the ecu solder joints. Did Programa inform you if there was a problem found?

Cheers,

Ray

finally got back to the M2 after e30 and lift install distraction...

ECU is at Programma for repair, so I started to take the Diff apart to fix the slop in output shaft.

feels like the left output bearing is a tad worn. will need to order up some new bearings and try to figure out how to get the inner races off the LSD spool.

to save someone else a search, i found this good "how to" on 320is diff rebuild on bimmerforums.

http://forums.bimmerforums.com/forum/showthread.php?t=1592551&highlight=320+diff+rebuild

I will save you the post Ray...or i could just get a new 4.10.....;-)

[M3M3]

So this rich idle issue has been driving me nuts. Keep hacking away at it, literally.

Have narrowed the issue to the fact that the TPS reading in the AN software would not go below 15% at idle. This meant that although the idle circuit in the ECU is “on”, the TPS reading put the fuel map used up into the next mapping cell..which adds more fuel since it is set up for “off idle” in that cell. Hmmm.

The non-stock TPS used for AN does not allow any adjustment due to interference with the fuel pressure regulator and a metal outcropping on the TB. Some clearancing was in order.

On the connector

And on the TB

End result was a little room for movement, but alas, no effect on the issue.

Got the ECU back from ProGrama…all tests showed it was fine, but had them reflow all the solder joints anyway. Bummer…was hoping the issue was the ECU. Put it back in.

Today Jim and I went through all the connections from the ECU to AN to TPS and to the Traqmate data acquisition module. All seemed well. Hmmm.

Plugged it all back together booted up the computer….hmmm…..we have an AN “green” TPS idle light! And a 12.9% idle TPS reading! That is what it is supposed to be! Turn the key and crossed fingers. Car ran fine. Idled perfectly AFR exactly where it was supposed to be. I am happy it is working again, but no idea what we jostled or “fixed”. That disturbs me a bit, but…

On to next project…working on those diff bearings.

Bearing outer races easy. Took only light tapping from the outside with screw driver and hammer popped them out.

Right side inner race came out easy with heat and a two jaw puller.

Left side….not so easy. Cut the cage off with dremmel

Tried three jaw puller and heat to no avail. There was just not enough lip on the race for the puller to get a good grab on.

Resorted to ugly but effective. Ground slice in race with dremmel and used chisel to split the race. Came right off.

Got the new bearings on no problem using old races or sockets to tap them on with hammer.

Will put rest of it back together tomorrow.

[ray_]

4.10? ;-)

Bravo!

I think the issue is probably in the TPS plug, or TPS itself. Happy that it's resolved.

I've got a high idle issue, but it's smoother than it was so I haven't done much with it.

The E24 brakelight switch decided to pack it in last Thursday I think. Heh.

Cheers,

Ray

[M3M3]

i am thinking issue may be wiring harness near ecu. i have two basically new TPS's and they both test out fine and identically. odd thing is if it was a wiring problem in the TPS/Baro circuit, it only seemed to affect the bottom of the TP range. upper range seemed fine. that almost points to issue in AN module. may actually take the car out for a drive today......then start taking the cams out. ;-)

mumble...mumble...4.10...

[M3M3]

More diff assembly today.

Outer side cover with new oil seal and bearing race

Inner bearing in on right side

The put it all together to see how it fit. Now comes the tricky part. Remember those shims under the rim of the side covers? They set the output bearing load and the lash on the ring and pinion. Available from bmw in 0.05mm increments. Mine were 1.65mm on each side according to my digital calipers. I hope that is accurate…

Anyway, with the new bearings, the existing shims were way off. lots of slop in the r&p and in the LSD. Removed the shims and put it all back together. adjusted the cover bolts until the lash felt ok (using left side cover) and the LSD carrier was good (right side cover). Measured gap with feeler gauge.

Final measurements. Any experts out there think I missed something in this process? I have not messed with diff internals before….

Will have to add some new shims to next BLUNT order…

Then…the reward…..put the airbox back on the M2. Rechecked the idle settings……AND WENT FOR A DRIVE!

35 minutes of grinning from ear to ear…..runs great! Reminded me how un-street friendly this car is….loud, stiff, rattles, twitchy. I can’t wait for track season to start!

Ok..time to start taking top of S14 apart to put the new cams in. oh boy.

[jgerock]

Glad you had fun on the drive....us non-government folks had to work today (traffic was light - that was a plus). Janice co-pilot?

[ray_]

Mine is like that too -- except for the stiff, rattles twitchy part. ;-)

Can't wait to drive it to work again tomorrow!

;-)

Ray

35 minutes of grinning from ear to ear…..runs great! Reminded me how un-street friendly this car is….loud, stiff, rattles, twitchy. I can’t wait for track season to start!

Ok..time to start taking top of S14 apart to put the new cams in. oh boy.

[M3M3]

Yesterday was the drudgery of fixing the e30 daily driver (rebuild cv joints in left halfshaft, R&R diff). while I had the spare e30 LSD out found the comparison between it and an e21/2002 diff interesting. E21 diff looks like a toy!

Then…started the S14 cams swap project..

Hmmm, gotta remember where the plug wires go…

Valve cover off.

Rear cam box cover off. have had oil leak here since day one. there was no gasket on it and the sealant they used was not everywhere. Notice shiny metal on corner…that is where leak was.

Next got it to TDC

“E” is not for exhaust….german for intake!

Pointer lined up with OT mark on pulley

Upper chain guide off

Dizzy cap off

Dizzy housing off and cam end cover off.

To be continued….

[ray_]

A before/after dyno comparison might be interesting. Ah, you do have that traqmate thingy. That will be worth a look.

Cheers,

Ray

[M3M3]

Timing chain tensioner out…the old style

Bending bolt lockplates

Carefully removing cam gear bolts. Notice paper towel to keep them from dropping in the engine. Yikes.

Cam gear off. zip ties used to keep chain/gear relation set.

Removing cam bearing caps. Backing off nuts quarter turn at a time one by one from front to back.

Caps off

Inside of bearing caps

Stock cam out

Comparison between lobes on stock and schrick

Lash cap/shim removed, just because.

More later…

[M3M3]

Covered the first cam with assembly lube and dropped it in.

Torqued it down

Jim came over and we then rolled the engine over slowly by hand hoping we did not feel valves hitting piston tops….all smooth.

Then repeated process for intake cam. Cam lubed and dropped in.

Bearing caps on

Lock plates on cam gear ready for bending

Gears on

Both cams in

Rolled engine over again to check for any feeling of contact. None. No idea what the actual piston to valve clearance is, but it ain’t zero..

Then checked valve clearances. Spec is .010in. all close. #1 exhaust may be a bit low, will get some thinner shims.

Need to now order new timing chain tensioner and oil seal for dizzy housing, then assemble rest of parts.