Author Topic: I need some Serious $#%@#$in Help seriously (Read 26724 times)

B318M42W · « **Reply #45 on:** February 19, 2011, 02:51:34 AM »

Just had a flash about timing and cam sensor relation... when you put the sprockets back on, did you put the pin from the (exaust) gear at the right spot? that pin triggers the cam sensor and tells the ECU when to send a spark. It might be off by just 1-2 teeth, enough to have a decent idle, but too much to get good performance. valve cover will have to come off and possibly even the upper timing case cover to check.
I have clear pics of the said pin when I did that job, just scroll down a little
http://www.m42club.com/forums/showthread.php?t=7517&highlight=B318m42W

fiftytakedowns · « **Reply #46 on:** February 19, 2011, 03:05:42 AM »

BOth arrows are pointing up. Im almost positive it's in the right spot I have nearly checked and adjusted 4 times.

fiftytakedowns · « **Reply #47 on:** February 21, 2011, 08:22:35 PM »

Im never going to figure this out.

fiftytakedowns · « **Reply #48 on:** February 21, 2011, 08:25:18 PM »

So today I did a sensor test by

driving car.
unplug sensor
drive again.
evaluate.
repeat.

I did that for every sensor:
Camshaft position
AFM
TPS
TPS and ICV
ICV
O2

Every single time it had the same symptoms.
also every time the car would run alright until about a minute or two of driving, then the misfiring would happen.

I also replaced the injectors and FPR with a spare set I had.

colin86325 · « **Reply #49 on:** February 22, 2011, 12:19:25 PM »

Man, I admire your patience. I think you might have some kind of issue in your wiring harness, but there are a couple of longshot things you could check.
Sometimes the rubber in the crank balancer cracks and allows the balancer to precess or wobble, throwing off the CPS.
Also, the thrust bearing is a weakness and can wear, causing excess crank thrust. It might be possible to throw the CPS signal off if thrust was too excessive.

fiftytakedowns · « **Reply #50 on:** February 22, 2011, 01:05:39 PM »

So what do i do from here?

longtallsally · « **Reply #51 on:** February 22, 2011, 02:08:29 PM »

You are seriously going to punch me through the Internets, but I still think you should disassemble the entire front of the car and inspect all things timing related.

All your codes seem to me to be point back to timing and since you just did the chain and such. Maybe the CPS wire is frayed somewhere along the path and arcs or grounds out somewhere? I dunno, but I still just think it has to be this.

So back in my M20 days I did the timing belt, tensioner, etc as part of some regular maintenance. As I should have, I turned the motor over by hand a few times to make sure I had the timing right which I swore I did.

Sure enough, I turned it over and it ran- like butt. It was a merry christmas and I got lucky and didn't blow the head. I took the whole thing apart and re-checked. The second time, it was perfect. So this is why I think it is totally possible that this is the issue for you...

fiftytakedowns · « **Reply #52 on:** February 22, 2011, 04:24:28 PM »

Quote from: longtallsally;101688

You are seriously going to punch me through the Internets, but I still think you should disassemble the entire front of the car and inspect all things timing related.

All your codes seem to me to be point back to timing and since you just did the chain and such. Maybe the CPS wire is frayed somewhere along the path and arcs or grounds out somewhere? I dunno, but I still just think it has to be this.

So back in my M20 days I did the timing belt, tensioner, etc as part of some regular maintenance. As I should have, I turned the motor over by hand a few times to make sure I had the timing right which I swore I did.

Sure enough, I turned it over and it ran- like butt. It was a merry christmas and I got lucky and didn't blow the head. I took the whole thing apart and re-checked. The second time, it was perfect. So this is why I think it is totally possible that this is the issue for you...

I understand that, but I really dont need to take it all apart because you can take the cam gears off without taking off the lower sections of the covers. I want to avoid buying new gaskets wasting more money on anything else that I have already looked at. I had both cam gears squared up with the piston at the top of it's stroke. I guess I can go over it again, who knows, maybe the twelfth time's a charm.

Also, why would the computer start misfiring after a little bit of driving then? or cruising, then when it's reset its good again for a little?

fiftytakedowns · « **Reply #53 on:** February 22, 2011, 04:40:01 PM »

once I figure this out Im going to work at retrofitting some ITBs from a Suzuki so who's got the magic answer

Did some sensor Testing:

Coil 1: WAs Sparatically Changing Ohm Levels:
from .03 to .05
Coil 2: .015
Coil 3: .015
Coil 4: .015

These were the coils Off of a Coil on Plug conversion, not sure if that makes a difference.

AFM:
got a consistent reading between pins 3 & 4 to 3.94V through -.06V
Between pins 1 & 2 : 3.8 V

TPS:
At idle between Pins 1 & 2 4.3V
Full throttle: .96V

Between pins 1 & 3 5v
Between pins 2&3 at Idle .62 V
full throttle: 4.0V

and its doing 19 Mm HG under vacuum at idle

colin86325 · « **Reply #54 on:** February 22, 2011, 10:00:55 PM »

If you need a decent COP coil I can send you one. Coil 1 seems sketchy, but maybe it's the only one with valid resistance. I cannot recall the proper coil resistance, but i believe it was larger than .015. I'd google the the spec for the M54?? coils and compare.

RE:What do you do now?
Well I would manually check for play in the crank damper. You would have to remove the belts and check for play. I don't know if there is a spec, but it should be imperceptible with your hand. With the belts off you can also rev the engine while looking at the damper to see if it wobbles. You could fit some run-out indicators that should not contact the damper unless to indicate a run-out problem.

As far as the crank run-out, I know there is a spec in Bentley for a disassembled engine, but I don't know if there is one for checking the spec while the engine is in the car. Maybe Bentley has one listed? For this you would somehow press the crank hub towards the block to "zero it out" and then take a measurement. Then have a buddy press the clutch pedal while you measured the amount of forward travel that the crank hub had made.
Unlike the M20 and the S14 engines that I'm used to, these M42s eat the damn thrust bearings and then the wear cuts into the thrust face of the crank, rendering the crank useless. I had to reject 3 used cranks before I found a nice used one for my rebuild because they all had dished-out thrust faces.

fiftytakedowns · « **Reply #55 on:** February 22, 2011, 10:21:06 PM »

it looked to be spinning straight when I was lookin, which I did check. I didnt have a torque gun so I could only torque it the best I could. I will try to to disessemble it and re-torque with a gun then.

I believe the coils are supposed to be .4-.8 or somethign

what would cause the CPU to spit out those codes though that has me curious.
also, If I wanted to test the wires for corrosion between the terminals and connectors, between ECU and sensor Ig uess.. what values should I look for in ohms?

longtallsally · « **Reply #56 on:** February 23, 2011, 02:28:36 PM »

Quote from: fiftytakedowns;101694

Also, why would the computer start misfiring after a little bit of driving then? or cruising, then when it's reset its good again for a little?

You got me on that one. Like I said, perhaps the tensioner is wonky and the computer takes a sec to get the readings? I'm grabbing at straws now and really don't know my way around this motor like Colin, so I'll bow out...

fiftytakedowns · « **Reply #57 on:** February 23, 2011, 03:07:02 PM »

LOL noooooooo I've lost another mind.

colin86325 · « **Reply #58 on:** February 24, 2011, 05:14:28 PM »

BTW, I found the M50 coil specs:
You should have 0.4 to 0.8 ohms between the two outer terminals in the coil plug housing. The resistance of the connector boots should be about 1.9K ohms.

fiftytakedowns · « **Reply #59 on:** February 25, 2011, 01:33:35 AM »

so today I double checked TDC with cams and crank. found notch on pulley etc. etc.

replaced cracked intake boot.
replaced main relay
(both with brand new OEM)

I also took off the crank damper, impacted the mother on and then put on the extra pulleys. I was hoping this would eliminate a vibration that possibly might occur causing screwy CPS signals. just precaution.

I didnt really get a chance to drive it because It kept on wanting to overheat after I put the radiator back in. so I am letting it sit over night, then I will run the car in teh morning with the rad cap off to bleed out the air.

One last thing. There is a temperature sender on the right side of the radiator with a Plug that goes into it a three pronged one. my actual prong holder broke, so all I have is the three wires, and I dont know which wire goes to the respective prong in the plug, so if someone can take a picture of that for me or make a diagram that would be greatly appreciated as I have had that unplugged.