Dill Emma- 87 Timing
12-01-2016, 05:59 PM
#1
Le Mans Master
Thread Starter
Dill Emma- 87 Timing
Replaced TPS and adjusted it for .54 volts per procedure.
New timing chain & gears, installed straight up (no retard or advance).
Harmonic Balancer looked excellent when off, marked TDC with white paint, re-installed it. I don't believe the ring has slipped.
Marked timing tab at 6 deg BTDC with white paint.
Rotated engine for TDC #1 compression, lined up 6 degree timing marks on balancer and tab.
Dropped distributor in with coil wire connector facing perpendicular to drivers side and with rotor pointing directly at #1 tower (standard C4 HEI per FSM). With this arrangement, EST disconnected, timing light indicates the timing is way off (advanced).
Engine will not idle below about 1000 rpm and is running rich
Below 900-1000 rpm it misfires and quits, so I can't idle it down to set the timing at 600rpm.
With the EST wire disconnected, the timing mark does move with a change in rpm
To get the timing marks to line up with a timing light, had to rotate the dist clockwise about 25 degrees or 1 plug wire tower (retard it). (but at over 900 rpm)
I can't get this thing to idle or run clean.
What am I missing here?
I'd pull my hair out but it's already gone.
New timing chain & gears, installed straight up (no retard or advance).
Harmonic Balancer looked excellent when off, marked TDC with white paint, re-installed it. I don't believe the ring has slipped.
Marked timing tab at 6 deg BTDC with white paint.
Rotated engine for TDC #1 compression, lined up 6 degree timing marks on balancer and tab.
Dropped distributor in with coil wire connector facing perpendicular to drivers side and with rotor pointing directly at #1 tower (standard C4 HEI per FSM). With this arrangement, EST disconnected, timing light indicates the timing is way off (advanced).
Engine will not idle below about 1000 rpm and is running rich
Below 900-1000 rpm it misfires and quits, so I can't idle it down to set the timing at 600rpm.
With the EST wire disconnected, the timing mark does move with a change in rpm
To get the timing marks to line up with a timing light, had to rotate the dist clockwise about 25 degrees or 1 plug wire tower (retard it). (but at over 900 rpm)
I can't get this thing to idle or run clean.
What am I missing here?
I'd pull my hair out but it's already gone.
12-02-2016, 06:32 AM
#2
Replaced TPS and adjusted it for .54 volts per procedure.
New timing chain & gears, installed straight up (no retard or advance).
Harmonic Balancer looked excellent when off, marked TDC with white paint, re-installed it. I don't believe the ring has slipped.
Marked timing tab at 6 deg BTDC with white paint.
Rotated engine for TDC #1 compression, lined up 6 degree timing marks on balancer and tab.
Dropped distributor in with coil wire connector facing perpendicular to drivers side and with rotor pointing directly at #1 tower (standard C4 HEI per FSM). With this arrangement, EST disconnected, timing light indicates the timing is way off (advanced).
Engine will not idle below about 1000 rpm and is running rich
Below 900-1000 rpm it misfires and quits, so I can't idle it down to set the timing at 600rpm.
With the EST wire disconnected, the timing mark does move with a change in rpm
To get the timing marks to line up with a timing light, had to rotate the dist clockwise about 25 degrees or 1 plug wire tower (retard it). (but at over 900 rpm)
I can't get this thing to idle or run clean.
What am I missing here?
I'd pull my hair out but it's already gone.
New timing chain & gears, installed straight up (no retard or advance).
Harmonic Balancer looked excellent when off, marked TDC with white paint, re-installed it. I don't believe the ring has slipped.
Marked timing tab at 6 deg BTDC with white paint.
Rotated engine for TDC #1 compression, lined up 6 degree timing marks on balancer and tab.
Dropped distributor in with coil wire connector facing perpendicular to drivers side and with rotor pointing directly at #1 tower (standard C4 HEI per FSM). With this arrangement, EST disconnected, timing light indicates the timing is way off (advanced).
Engine will not idle below about 1000 rpm and is running rich
Below 900-1000 rpm it misfires and quits, so I can't idle it down to set the timing at 600rpm.
With the EST wire disconnected, the timing mark does move with a change in rpm
To get the timing marks to line up with a timing light, had to rotate the dist clockwise about 25 degrees or 1 plug wire tower (retard it). (but at over 900 rpm)
I can't get this thing to idle or run clean.
What am I missing here?
I'd pull my hair out but it's already gone.
Last edited by Joe C; 12-02-2016 at 06:42 AM.
12-02-2016, 08:31 AM
#3
Le Mans Master
Thread Starter
your 25° is close to the one tooth off or 30° on the distributor gearing. suggestion - #1 at TDC compression, pull your distributor up to disengage the gears. square up the distributor - coil wires perpendicular the engine's centerline. rotate the rotor only CCW a bit so it points to the center of the LH valve cover emblem, and slowly drop the distributor to engage. when engaged, and lowering the distributor, the rotor will move CW about 30° and should end up pointing to (approximately) the #1 spark plug. might take a little wiggle-giggle, but it should fall into place. when your done, rotate the distributor assembly slightly, just a few degrees CCW. that should get you in the 6° BTDC ballpark. good luck -
Yes... by rotating the dizzy to get the marks to line up, I basically already achieved that. I had planned to do that "fix" today. However, it will still not idle at 600rpm when it's done because it didn't when I rotated the dizzy.
12-02-2016, 09:52 AM
#4
Melting Slicks
Member Since: Sep 2008
Location: Cherokee National Forest TN
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No mechanical advance in the dist. With the EST wire disconnected the timing can be set @ any RPM.
The running issue is some other problem suggest checking the firing order. If rich
miss-fire has occurred the spark plugs will need to be cleaned.
Good luck.
The running issue is some other problem suggest checking the firing order. If rich
miss-fire has occurred the spark plugs will need to be cleaned.
Good luck.
12-02-2016, 10:31 AM
#5
Safety Car
My suggestion for the OP is to warm the car up with the EST connected and advanced timing, then once the car is nice and warm and willing to idle disconnect the EST and see if the timing can be set at 6 degrees.
12-02-2016, 07:49 PM
#6
Melting Slicks
Member Since: Sep 2008
Location: Cherokee National Forest TN
Posts: 2,376
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There may be a difference between the 87 MAF system & the 90 up speed density system IDK.
Bottom line the OP has an issue other than timing.
?, if there are timing issues with big cams why are factory ECU's being used with them?
Bottom line the OP has an issue other than timing.
?, if there are timing issues with big cams why are factory ECU's being used with them?
12-03-2016, 12:32 AM
#7
Race Director
12-03-2016, 06:35 AM
#8
question - just curious, but what is the TOTAL advance for a basic L98 tuned port? stock, ECM controlled, HEI distributor.
Last edited by Joe C; 12-03-2016 at 06:49 AM.
12-03-2016, 08:45 AM
#10
Le Mans Master
Thread Starter
This is not true, the system will advance the ignition when you exceed around 1100 RPM to a fixed number (I do not know the number but it does happen). I have seen this many times when the RPM is too high and people try and set the base timing. If you watch the timing with light with the EST disconnected you can see it happen. Cars with large cams that idle high have issues with this because it is hard to get the idle below 1000 RPM with the EST disconnected.
My suggestion for the OP is to warm the car up with the EST connected and advanced timing, then once the car is nice and warm and willing to idle disconnect the EST and see if the timing can be set at 6 degrees.
My suggestion for the OP is to warm the car up with the EST connected and advanced timing, then once the car is nice and warm and willing to idle disconnect the EST and see if the timing can be set at 6 degrees.
12-03-2016, 08:48 AM
#11
Le Mans Master
Thread Starter
I need a easy button to figure this out. Maybe I'll just install a 7psi fuel pressure regulator, 4bbl intake & carb and 1 wire distributor.
12-03-2016, 10:06 AM
#12
12-03-2016, 02:31 PM
#13
Le Mans Master
Thread Starter
Yanked the distributor and rotated the gear 1 tooth counterclockwise. Now with the 1/8 towers forward, it's at about 6 degrees.... but at over 1500rpm. Still can't idle it down. I need to eliminate the factory ignition system to figure this out. Does anybody make a "tuning" setup that replaces the factory connections for tuning? IE- Isolates the minimum ignition parts? I think it would just need distributor, fuel injector and a controller?