Turbo M30 Misfire, Ignition or Tune?

Discussion pertaining to positive pressure E28s.
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e38740imd
Posts: 436
Joined: Jun 17, 2013 12:36 AM
Location: Maryland

Turbo M30 Misfire, Ignition or Tune?

Post by e38740imd »

Good Morning all!!

i finally got the car back from the exhaust shop. and now im ready to start tuning and driving this car

Image


the car starts fine. and i can get it to idle ok with the afr around. 13.8 so far.

sometimes if i rev it up it will die when the RPM fall it doesn't catch iself all the time yet so i think i need to work on the ilde maps some more

under load there is a misfire that you can hear. car does build a little boost. as the bov open and close when the throttle closes

i have new:

new ngk spark plugs (bp7es)
new spark plug wires
new stock ignition coil
new distributor
new rotor

this is my first time playing with the MS2PNP. So im not even sure where to look if its the base map im using.

any help and insight?

in the mean time i will go towards wasted spark route when my parts come in the mail i will be using the Bosch 0221503002 coil for my wasted spark setup. i chose this to retain the stock spark plugs wires i already bought
marc79euro645
Posts: 445
Joined: Dec 09, 2008 12:33 AM

Re: Turbo M30 Misfire, Ignition or Tune?

Post by marc79euro645 »

Have you double checked the timing with a timing light?
Are you getting a steady strobe when you rev a little?
e38740imd
Posts: 436
Joined: Jun 17, 2013 12:36 AM
Location: Maryland

Re: Turbo M30 Misfire, Ignition or Tune?

Post by e38740imd »

marc79euro645 wrote: Sep 07, 2020 7:33 PM Have you double checked the timing with a timing light?
Are you getting a steady strobe when you rev a little?
i have not.

i wanted to but i dont understand how to

1. use one

2. how to use it on a 60-2 tooth set up.






i do know that most people say it should be at around 84 degrees etc but my base map is set at 97.

not sure if that could be the cause
tschultz
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Location: Denver, Colorado
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Re: Turbo M30 Misfire, Ignition or Tune?

Post by tschultz »

It is more likely your idle settings that may be causing issues with the car stalling. Worth checking timing with the light too.
marc79euro645
Posts: 445
Joined: Dec 09, 2008 12:33 AM

Re: Turbo M30 Misfire, Ignition or Tune?

Post by marc79euro645 »

You really need to confirm timing!
get an adjustable timing light
Set cyl #1 at tdc, pull #1 plug use a screwdriver in plug hole to determine TDC
make a pointer you can attach to a front cover bolt where you can see it.(or you could mark damper at vr pickup)
mark damper at pointer
set timing light to 10* (or whatever your idling at)
set timing on spark map at 10*
put clamp on cyl #1 wire
start car, at idle MS should read 10* stable (you may need to set adjacent cells to 10* as well to get stable 10* from MS)
using timing light set on 10* you should see light flash on TDC mark
If you don't see mark then your probably on the wrong TDC
stop motor
rotate until you get TDC mark /pointer again
now rotate crank 180* to other TDC, pull plug verify your at TDC
mark new TDC on damper
restart
you should see mark at flash line up with damper tdc mark
if not adjust trigger wizard to get MS to match timing light.
once you've got stable timing at idle, verify max timing for VR signal
watch for a steady advance when reving, be on the lookout for odd flashes that may indicate vr signal problems
if you're seeing odd flashes you may need to use different predictor algorithm, or tune the pots (R51 and R56 if I recall)
e38740imd
Posts: 436
Joined: Jun 17, 2013 12:36 AM
Location: Maryland

Re: Turbo M30 Misfire, Ignition or Tune?

Post by e38740imd »

marc79euro645 wrote: Sep 08, 2020 2:46 PM You really need to confirm timing!
get an adjustable timing light
Set cyl #1 at tdc, pull #1 plug use a screwdriver in plug hole to determine TDC
make a pointer you can attach to a front cover bolt where you can see it.(or you could mark damper at vr pickup)
mark damper at pointer
set timing light to 10* (or whatever your idling at)
set timing on spark map at 10*
put clamp on cyl #1 wire
start car, at idle MS should read 10* stable (you may need to set adjacent cells to 10* as well to get stable 10* from MS)
using timing light set on 10* you should see light flash on TDC mark
If you don't see mark then your probably on the wrong TDC
stop motor
rotate until you get TDC mark /pointer again
now rotate crank 180* to other TDC, pull plug verify your at TDC
mark new TDC on damper
restart
you should see mark at flash line up with damper tdc mark
if not adjust trigger wizard to get MS to match timing light.
once you've got stable timing at idle, verify max timing for VR signal
watch for a steady advance when reving, be on the lookout for odd flashes that may indicate vr signal problems
if you're seeing odd flashes you may need to use different predictor algorithm, or tune the pots (R51 and R56 if I recall)

when you say Tdc of cylinder 1 do you mean the tdc of when setting the motor together? just want to clarify

i picked up and adjustable timing light today

and the marked points. should it be the normal tdc marks on the damper and timing cover?
marc79euro645
Posts: 445
Joined: Dec 09, 2008 12:33 AM

Re: Turbo M30 Misfire, Ignition or Tune?

Post by marc79euro645 »

"when you say Tdc of cylinder 1 do you mean the tdc of when setting the motor together?"

Yes, the plug should spark just before TDC event where both valves are closed.

"should it be the normal tdc marks on the damper and timing cover?"
I can't speak to that, I don't have a 60-2 damper installed yet.

I don't know if you can see that properly with motor running. I positioned mine on the driverside, just below the thermostat housing and above the alternator bracket was a good spot for me to shoot clear to the damper. I made a simple pointer from a piece of 1x2 aluminium angle, mounted from timing cover bolt.
e38740imd
Posts: 436
Joined: Jun 17, 2013 12:36 AM
Location: Maryland

Re: Turbo M30 Misfire, Ignition or Tune?

Post by e38740imd »

been a long time since i posted so i figured i would post up an update.


found the misfire issue:

Image

injector connector wasnt seated correctly. i was about to go mad! fixed the connector and ensure it was seated on the injecor, and boom!


car started with no misfires!!!!! drove around with 5 psi for a little. it feels great and fast for 5 psi.


still tried to get a good idle map going but car dies once you start driving when put in neutral at lights. so i will see what i can do. goal is to get 25psi from this current set up
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