1974 Valiant Scamp, timing retarding when revved
Guys, I really appreciate the input! Well, a bit more background and some results:
This is a ATK 318 motor (DD03), stock replacement as far as I know. 20k miles on it.
It has an Edelbrock 4BBL carb on it, Edelbrock Performer intake.
Distributor cap, rotor, and wires are all fine. Rotor can be turned slightly and returns as it should, advance plate moves, swapped coil wires, installed new fuel filter and filled up with fresh 93. None of this resolved the issue, I rechecked with the timing light on both #1 and #6, at idle timing is 5* advanced, if I open the throttle and hold it by hand a bit progressively more and more, timing continues to retard until I can't see it on the timing tab. It really sounds like it has a giant cam in it, and revs very freely, it almost feels like a gunked up carb needing a rebuild but the timing issue is throwing me for a loop. I'm admittedly more familiar with GM HEI set ups, and I'm very tempted to go ahead and put an HEI system in, I'd hate to ruin the original ignition system but it seems overly complicated.
I am going to order a rebuild kit and clean out the carb to be safe, it's a fun thing to do anyway. However, on the ignition I noticed a couple of things that look like they might be in poor shape, though I'm not certain what they do.
The ignition box here, or ECU as I've seen it called, I assume is similar to the HEI modules. It appears to have leaked its' guts on the fender, can these be bypassed or diagnosed to eliminate it as a potential issue?
The Ignition coil has been....remote mounted by the previous owner, it also appears to have been rewired and has a purple and blue wire.
The voltage regulator on the passenger fender appears to have also leaked its' guts, looks like some sort of dialectic fluid. Almost like dried tree sap.
I'll try to get a video of the way it runs tomorrow when my neighbors are less likely to stab me, but I am really interested to know more about the ignition system and how to bypass as much as possible for troubleshooting purposes if anyone knows more about this odd electronic ignition.
Thanks!
Guys, I really appreciate the input! Well, a bit more background and some results:
This is a ATK 318 motor (DD03), stock replacement as far as I know. 20k miles on it.
It has an Edelbrock 4BBL carb on it, Edelbrock Performer intake.
Distributor cap, rotor, and wires are all fine. Rotor can be turned slightly and returns as it should, advance plate moves, swapped coil wires, installed new fuel filter and filled up with fresh 93. None of this resolved the issue, I rechecked with the timing light on both #1 and #6, at idle timing is 5* advanced, if I open the throttle and hold it by hand a bit progressively more and more, timing continues to retard until I can't see it on the timing tab. It really sounds like it has a giant cam in it, and revs very freely, it almost feels like a gunked up carb needing a rebuild but the timing issue is throwing me for a loop. I'm admittedly more familiar with GM HEI set ups, and I'm very tempted to go ahead and put an HEI system in, I'd hate to ruin the original ignition system but it seems overly complicated.
I am going to order a rebuild kit and clean out the carb to be safe, it's a fun thing to do anyway. However, on the ignition I noticed a couple of things that look like they might be in poor shape, though I'm not certain what they do.
The ignition box here, or ECU as I've seen it called, I assume is similar to the HEI modules. It appears to have leaked its' guts on the fender, can these be bypassed or diagnosed to eliminate it as a potential issue?
The Ignition coil has been....remote mounted by the previous owner, it also appears to have been rewired and has a purple and blue wire.
The voltage regulator on the passenger fender appears to have also leaked its' guts, looks like some sort of dialectic fluid. Almost like dried tree sap.
I'll try to get a video of the way it runs tomorrow when my neighbors are less likely to stab me, but I am really interested to know more about the ignition system and how to bypass as much as possible for troubleshooting purposes if anyone knows more about this odd electronic ignition.
Thanks!