TR-6 Ignition with SD-2 Issue ...lose spark to half of plugs?

[greeneyegi]

ive finally gotten rid of 99% of my little gremlins here and their.
new wiring harness,aem map 3.5,tr-6,sd2 chip,alky,powerlogger,on and on.

so my latest issue was only happening during startup.it would usually do it only after warmed up.
now more and more,once after it was already running.

it floods,then seems like it runs on 3 cylinders.

so today I started it and it started perfectly.i shut it off,then I pulled 3 wires off.one on each of the sets of towers on the coil.i then started it with just 3 plugs firing and it is exactly whats happening.last night at the tracks it flooded but after trying to start it for 3 min it finally ran fine.
any ideas,where to start?
bob?

 

[TurboBob]

odd, never seen that.

the intermittent nature of stuff like this makes it hard to find sometimes. with it running, you can try wiggling the
wiring harnesses and see if you can find something.

flaky injector harnesses and stuff like that can cause dropped cylinders that will sound like missing spark.

if you have an infrared temp gun, you can see which cylinders are not hitting by measuring the header temperature.

Bob

 

[greeneyegi]

odd, never seen that.

the intermittent nature of stuff like this makes it hard to find sometimes. with it running, you can try wiggling the
wiring harnesses and see if you can find something.

flaky injector harnesses and stuff like that can cause dropped cylinders that will sound like missing spark.

if you have an infrared temp gun, you can see which cylinders are not hitting by measuring the header temperature.

Bob

I thought of that, I'm going to get one today.I'll report back.I was thinking maybe coil?

 

[greeneyegi]

So today I replaced coil, did same thing.I closed the gap on plugs a little to 32.while ight was flooding I pulled the wires of the coil at same time, but they all firing..
When it first had Ann issue today uft was the 5,6 cylinder that was cold.

 

[TurboBob]

if all the plugs are firing, then perhaps its not an ignition issue.

 

[greeneyegi]

if all the plugs are firing, then perhaps its not an ignition issue.

itss definitely flooding,I can hold to floor,, It will start and run but like it's on three cylinders.andit only runs right after I restart

 

[TurboBob]

ok, you should probably check the powerlogger to make sure its plugged in securely, then check the cylinder balance parameters and make sure they are 0.

 

[greeneyegi]

ok, you should probably check the powerlogger to make sure its plugged in securely, then check the cylinder balance parameters and make sure they are 0.

everything looks good,heres a log from when it was a run down the track,i couldn't grip anything,i parked it.came back 1/2 hr later and it flooded.
im going to put new plugs in it,these are only 2oo miles,and lower the crank fuel 15%.
any thing else to check?

 

[Eric Stage I]

IAC at zero? Also need to save logs with key on, so we can see the rest of the parameters.

 

[greeneyegi]

IAC at zero? Also need to save logs with key on, so we can see the rest of the parameters.

I didn't even notice that...ok ill save with key on.
ive never dealt with that what would be the check on that being intermittant

 

[greeneyegi]

I cant do a search .....again

 

[greeneyegi]

this one here it was running then it dies iac goes zero.

 

[Eric Stage I]

That run doesn't show the engine dying and IAC going to zero. It shows the engine being started, the IAC starts at 140 like normal, then it drops down to zero, engine still running. Are we looking at the same log?

The IAC is going to zero most likely because the min air screw is not set correctly. Set the min air screw so the IAC is about 15 at a hot idle in park. To be specific, start the engine, get it idling, slowly unscrew the min air screw and the idle RPM will drop, then the IAC # will rise. If you don't know what the min air screw is, its the throttle stop screw on the throttle body. Keep adjusting the screw until the IAC reads about 15 give or take.

When you're done you may need to re-adjust the TPS so it's in the .40-.46 area at idle.

 

[greeneyegi]

ok here is one after I just tuned it.

 

[Eric Stage I]

Looks pretty good there. Good job. Lets see what happens with the miss issue. If you can catch it happening in a log, maybe we can spot something.
What plugs are you using now?

 

[greeneyegi]

Looks pretty good there. Good job. Lets see what happens with the miss issue. If you can catch it happening in a log, maybe we can spot something.
What plugs are you using now?

ngkur6 resistor type.
I took it for a ride everything beautiful.i let it sit for about 30 min and went out to fire it,and it flooded.so I took a log ,then finally got it started.shut it off ,restarted it and it idled then just shuts off.
then restarted again.

ps I put a fuel pressure gauge on it,it kept 36#of pressure for 3hours and I released it.so no leaky injectors.

 

[BEATAV8]

this sounds a lot like what happened to me last weekend. Had some serious stalling problems, then flooding with a very difficult re-start (often no-start).

Captured a few files showing some odd BLM grid behavior that was captured during some stalls, and it continues to occur after the stall. Eric and I were chatting back and forth about it earlier this week.

I'm also running a TR6 but I think it's a non contributor to the issue. TR6 LEDs show cam, crank, sync successfully, but the run LED drops out when there's a failure to start and the ECM shows no RPM.

The attached files show the strangeness in the BLM grid. See if yours is doing the same when its having issues. I suspect an ECM issue on mine.

 

[BEATAV8]

your stall looks like mine but I don't see the same BLM grid strangeness.

 

[greeneyegi]

this sounds a lot like what happened to me last weekend. Had some serious stalling problems, then flooding with a very difficult re-start (often no-start).

Captured a few files showing some odd BLM grid behavior that was captured during some stalls, and it continues to occur after the stall. Eric and I were chatting back and forth about it earlier this week.

I'm also running a TR6 but I think it's a non contributor to the issue. TR6 LEDs show cam, crank, sync successfully, but the run LED drops out when there's a failure to start and the ECM shows no RPM.

The attached files show the strangeness in the BLM grid. See if yours is doing the same when its having issues. I suspect an ECM issue on mine.

yeah ,your check engine light flicks on for a second,and the clear code comes on also.yeah mine dosnt seem to have that type of issue,

 

[Eric Stage I]

It looks like it's commanding the right cranking fuel. On the log where it stalls, everything looks good, except the RPM's just drop off. Maybe take a look at the IAC motor and passageway just to make sure it's not starving for air. It looks like it fires, but then doesn't flare up to the normal 1200-1500 or so initially.