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lee did put a recurve kit in there. I just heard from duane, he mentioned something about the motor mount being loose and that's where the ground strap is. Could a poor ground be the culprit?
The 1974 model did not come with HEI nor a catalytic converter. What it DID come with is ignition points and a resistor wire to feed the ignition coil. This added resistance in the 12 vdc power line acts to limit the current going to the ignition. That prevents points 'burning' and over-current to the coil.
If your wire is still the resistance wire (can't tell by looking at it), you need to swap-out the wire [coming from the bulkhead connector on the firewall and going to the ignition coil or HEI unit] with a regular piece of 14 awg wire. If you want to keep the resistance wire (for originality), splice the regular wire into the resistance wire at the bulkhead connector; then roll up the resistance wire and tie-wrap it to the firewall for 'safe-keeping'. Run the 'new' wire to the 12vdc [input] for the HEI unit. This is most likely the problem causing your 'weak' spark.
P.S. The car starts OK because the FULL 12 vdc start voltage comes from the starter solenoid when ignition key is in "START' position. When key is released [to RUN position], power then comes from the resistance wire.
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by Richard Daugird
Wow I did not know that. Cheap China crap with the Delco name, ain't that great? I wonder, how would I be able to tell if a module from a boneyard was OEM, and not replaced with the same crap I have now sometime in it's past? I used to get parts from the junkyard all the time, 30 years ago. But never electrical parts, as a rule. Always got that stuff from the store or dealer. Of course, that was back when we still had an industry in America...
The original HEI modules were designed and manufactured by Delco Electronics division of GM (Kokomo, Indiana), and the distributor/coil was manufactured by Delco-Remy division of GM (Anderson, Indiana). These, along with several other GM component divisions were sold off in the late 90s, as I mentioned earlier. The OEM modules have a couple stamped/molded labels on the cover: GM and 466. GM, for obvious reasons, and 466 is the manufacturer location ID (Kokomo).
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by Richard Daugird
In the event that I can't find OEM, what would be my next best bet? The MSD gets great reviews, I was figuring I'd get an MSD coil to go with it.
I'm probably not the guy to ask for recommendations on aftermarket ignition stuff. I avoid them at all cost. But, IIRC, Standard Products is/was an authorized replacement manufacturer of GM/Delco ignition parts. That's as far as I care to wander off the reservation.
I put an accel distributor and coil in last year because the oem advance was frozen, it wants 12v to run. I’m pretty sure it’s China made. I just put in a davis module with rev limiter I’ll try out this weekend. I keep the working oem module in the glove box just in case.
O.K. I found it. For $15 it's worth a try, all good reviews except two, from four and six years ago. Gonna fix that ground, test the coil, and try it out. I'll keep a spare too.
Had your problem too with street fire hei (junk)
replaced 4pin module and coil with Davis unified ignition DUI parts. All good for 2 yrs now. Just FYI.
Had your problem too with street fire hei (junk)
replaced 4pin module and coil with Davis unified ignition DUI parts. All good for 2 yrs now. Just FYI.
In defense of MSD StreetFire, I had a modge fail years ago (2009). Left me stranded, flatbed ride home.
Some how I got a hold of MSD tech and he said they were aware of a bad batch. Circuit board inside the unit would open with heat.
He sent me not one, but two brand new replacement modges free. No problems since.
But I do carry a spare modge & tools behind the seat.
Last edited by HeadsU.P.; Jul 16, 2021 at 08:18 PM.
FWIW, the HEI replacement in my 79 is a NOS ZZ4 crate engine take-off ACDelco unit made in Taiwan. I don't know where they are made now, but ROC is not the same as PRC.
Weak spark can be voltage or coil. The module either works, or not, and may work again after cooling.
I just got home from work, the car fired immediately. May be the ground strap. I will definitely check the whole system and keep a spare. Thanks so much everyone for all the responses.
Mark my man your car is a friggin' monster. I have known of the Davis stuff for quite some time, I may just need to heed your recommendation.
There was a cheap Chinesium module and coil in the car when I bought it with one of those crappy HEI tach dizzys. The module would stop working once the engine heated up. I rebuilt the mechanical advance (vacuum actually was fine) and replaced the module and coil with DUI parts, opened up the spark plug gaps, and she’s a fire breather now!
Hope you are up and running strong soon!
Mark (other Mark)
It also has a FAST EFI that works well now, but the PO had an external FP and regulator with a too small return causing FP to periodically drop to zero and the engine would stall. It was set at 43 psi. I replaced it with the Sniper in tank module set at 58 psi, upgraded the EFI controller to the color handheld so I could reset the fuel pressure to 58 psi (shorter injector cycling), and manually tune the engine. Like the factory ratings, my 475hp sticker is VERY conservative!
The 1974 model did not come with HEI nor a catalytic converter. What it DID come with is ignition points and a resistor wire to feed the ignition coil. This added resistance in the 12 vdc power line acts to limit the current going to the ignition. That prevents points 'burning' and over-current to the coil.
If your wire is still the resistance wire (can't tell by looking at it), you need to swap-out the wire [coming from the bulkhead connector on the firewall and going to the ignition coil or HEI unit] with a regular piece of 14 awg wire. If you want to keep the resistance wire (for originality), splice the regular wire into the resistance wire at the bulkhead connector; then roll up the resistance wire and tie-wrap it to the firewall for 'safe-keeping'. Run the 'new' wire to the 12vdc [input] for the HEI unit. This is most likely the problem causing your 'weak' spark.
P.S. The car starts OK because the FULL 12 vdc start voltage comes from the starter solenoid when ignition key is in "START' position. When key is released [to RUN position], power then comes from the resistance wire.
OP mentioned he replaced the original points distributor and that they disconnected and taped off the resistance wire when I brought it up already..
I'm probably not the guy to ask for recommendations on aftermarket ignition stuff. I avoid them at all cost. But, IIRC, Standard Products is/was an authorized replacement manufacturer of GM/Delco ignition parts. That's as far as I care to wander off the reservation.
Normally I agree they make decent stuff but in my case the standard products module was ironically the shortest lived module I had in my car... It left me stranded in Niagara Falls looking for a ride to the auto parts store. Thats when I decided to carry a spare.
Last edited by augiedoggy; Jul 17, 2021 at 10:32 AM.
augie...
Thanks for the 'heads up'. When I intitially see a long thread, I tend to focus on the OP's first post and how it's going toward the end. Sometimes I miss [significant 'stuff'] in the middle.
