Does the tach drop out entirely when it cuts? Have you tried a different CPS (oem metal one preferably).
Announcement
Collapse
No announcement yet.
Lost in a sea of tuning... (Ostrich 2.0)
Collapse
X
-
Dumb question, but is your ECU seeing a bad condition (excessive lean/rich, loss of timing, etc.) and initiating a fuel cut as a protection? Do you have any engine protections turned on in the software?sigpic
1987 - 325i Convertible Delphin Auto [SOLD], 325i Convertible Delphin Manual [SOLD]
1989 - 325i Convertible Bronzit m30b35 swapped [SCRAPPED], 325i Sedan Alpine Auto[DD]
1991 - 325i Coupe Laguna Manual [Project], 535i Sedan Alpine [SCRAPPED]
Comment
-
Originally posted by Digitalwave View PostDoes the tach drop out entirely when it cuts? Have you tried a different CPS (oem metal one preferably).
Originally posted by McGyverDumb question, but is your ECU seeing a bad condition (excessive lean/rich, loss of timing, etc.) and initiating a fuel cut as a protection? Do you have any engine protections turned on in the software?
If I hold the throttle all the way open, the WBO2 shows it going lean, and I get a backfire.
If I press the throttle moderately, it accelerates nicely.
Comment
-
Originally posted by Tinkerer007 View PostI am not familiar with the engine protection feature. I am running a tune from SSSquid that is for my engine.
Originally posted by Tinkerer007 View PostIf I hold the throttle all the way open, the WBO2 shows it going lean, and I get a backfire.
If I press the throttle moderately, it accelerates nicely.
Standalone: Are you using an e36 variable TPS? Did you calibrate the sensor?sigpic
1987 - 325i Convertible Delphin Auto [SOLD], 325i Convertible Delphin Manual [SOLD]
1989 - 325i Convertible Bronzit m30b35 swapped [SCRAPPED], 325i Sedan Alpine Auto[DD]
1991 - 325i Coupe Laguna Manual [Project], 535i Sedan Alpine [SCRAPPED]
Comment
-
Check the condition of the crank damper, specifically looking to see any visible cracks in the rubber. If you pry on the outside a bit, does it move a lot relative to the hub? The rubber can start to go on these, causing the outer toothed wheel to get wobbly, and then ECU loses track of crank position. It could definitely be in the process of failing and causing RPM-related problems.
Comment
-
Originally posted by McGyver View PostDumb question, but is your ECU seeing a bad condition (excessive lean/rich, loss of timing, etc.) and initiating a fuel cut as a protection? Do you have any engine protections turned on in the software?
Originally posted by bmwman91 View PostCheck the condition of the crank damper, specifically looking to see any visible cracks in the rubber. If you pry on the outside a bit, does it move a lot relative to the hub? The rubber can start to go on these, causing the outer toothed wheel to get wobbly, and then ECU loses track of crank position. It could definitely be in the process of failing and causing RPM-related problems.
Tinkerer007 Whet compression numbers do you have after moving the cam?
Comment
-
Originally posted by McGyver View Post
Are you using your stock Throttle Position Sensor? Is your TPS adjusted and functioning correctly? Does it signal WOT when the throttle is wide open?
Standalone: Are you using an e36 variable TPS? Did you calibrate the sensor?
Comment
-
Originally posted by ForcedFirebird View PostThat makes me wonder. More than once at the shop I have come across an engine build where the assembler didn't tighten the crank bolt enough. When that happens, the reluctor is relying on the woodfruff key. That key gets damaged and the crank hub moves causing all kinds of issues.
I suspect that my HG blew in a large part because the rubber in the damper wheel failed and let the toothed ring go partially unconstrained, leading to the ECU firing the ignition way too early. I guess if one was "lucky" and they instead had the woodruff key shear, the damper would get "stuck" a little off and just cause severely retarded ignition timing.
Comment
-
Originally posted by Tinkerer007 View Post
Honestly, it may well be the dynamic compression or something like what FF was suggesting. I can't quite think of what else would lead to a cut / misfire like that.
Comment
-
Originally posted by bmwman91 View Post
Oof, yeah that's a recipe for a bad time. A lot of folks don't quite know how important the toothed ring on the damper is...the single most important thing for the ECU!
I suspect that my HG blew in a large part because the rubber in the damper wheel failed and let the toothed ring go partially unconstrained, leading to the ECU firing the ignition way too early. I guess if one was "lucky" and they instead had the woodruff key shear, the damper would get "stuck" a little off and just cause severely retarded ignition timing.
Comment
-
Originally posted by ForcedFirebird View Post
Actually what happens is the key gets wallowed out from acel/decel and the timing becomes erratic. Of the ~.5 dozen times I've come across it, it blew one stroker motor. After dissecting it, put an angle finder on it and the reluctor could move something like ~10° advanced to -22° retarded while the crank was stationary. o.0
Comment
Comment