Poor life choices - C4 content

In reply to EvanR:

You're likely sort of correct. I'm fairly confident my new balancer does not have the same timing mark position as the original one, because as I discovered recently Chevy used 3-different positions over the years to correspond with differences in timing covers.

I've attempted to confirm/disprove this, but haven't had any success yet. So at this point I'm basically guessing at the advance.

I just spent an hour testing & tuning. First I re-checked the accelerator pump engagement. It was pretty close to spec, although I noticed that if I adjust it so there's no gap between the actuating lever and the pump lever, I cannot fit a 0.015 feeler gauge between the two, as I should be able to per Holley. I'm not sure if it's a problem though?

I also re-checked float level and discovered the rear was pretty low. I adjusted it up & I think it's ok now, but I'll check again before I start it next time.

Neither of those made much change, so I started increasing the advance again, which helped slightly. The miss tonight was limited to 1900-2100rpm, so I narrowed the gap by 100rpm. Also, one drive I was able to very very gradually accelerate(more like steady-state cruise) through that rpm range without it missing. I couldn't duplicate it though.

Have you checked the HEI bushings/bearings for slop? I had an old point type ignition that would stutter/miss when going from cruise to accel and the bottom bushing was worn out.

In reply to Miller Lake Monster:

No, I've not. Although I got the HEI at a rummage sale, it appeared unused. I was wondering whether the weight pivots might need a dab of grease or drop of oil though?

Not much garage time tonight, but I double-checked the float level. It seems to be about perfect - I made a "dipstick" from a bent zip tie, and as soon as I insert it into the port on the bowls fuel dribbles out, so it's right at the bottom of the hole.

I also swapped out the 35 discharge nozzles for the 28 one originally on the carb, but still no change. I still have the miss between 1900-2100rpm.

My next step will be to swap out distributor springs again. I had 1-light and 1-medium, then I stepped up to 2-mediums. I'll try swapping in 1-heavy spring next time and see if that makes a difference.

Are we sure its not electrical? Its an awfully specific rpm, while being independent of throttle or gear.

In reply to Dusterbd13:

+1, like a bad dist module.

Crackers wrote: In reply to Dusterbd13: +1, like a bad dist module.

Hmm.....

Hadn't thought about the module. I was thinking chassis harness issues due to efi deletion, but module is much easier to check.

In reply to Dusterbd13:

Interesting possibility... I've never dealt with HEI modules before, is there a way to test it, or should I just get another to swap out?

If you change the timing curve, springs and it gets better or worse, then keep trying different spring set-ups. Maybe it actually needs more timing.... Does anybody know a good timing curve for this type of engine? Most of what I normally deal with runs at much higher RPM....

In reply to TED_fiestaHP:

I've changed springs twice - from stock, to 1-light/1-medium from the recurve kit, then to 2-medium springs. Neither made a difference that I could feel.

Isn't this an unproven no name aftermarket distributor? I'm not sure how you test one, and that's a weird sounding way for one to go out, but I'd put the module on the suspect list. They're cheap enough to throw one at it, not a bad spare part to keep around in any event.

In reply to BrokenYugo:

Correct - unknown brand, but apparently new condition.

Someone last night also suggested I should check the distributor shaft for magnetism, as that would interfere with the pickup. So that's on the list to check too.

"Guilty until proven innocent"

I have learned the hard way, over many years, to not give credit or quarter to any part for virtue of being "new". Especially in today's world of Chinesium alloys, all you can assume about a new part is "It has never worked" yet.

Pete did you replace the Module you repaired?

In reply to GTXVette:

I'm still using the module it came with. It wasn't actually the module that was bad, it was the crimp on the terminal on the connector the module plugs into. I checked it when I swapped springs and it's still intact.

did you pull on it like when the Base plate Advances? Just shooting into the Dark here.

In reply to GTXVette:

I turned the baseplates by hand after I changed the springs to make sure they were moving freely(should I give them a drop of oil or grease?), but I never thought to check the module while I was doing it.

I hate to recommend throwing E36 M3 at the problem and see what sticks, but I do think testing a different ignition control module would definitely help. My gut says that that's failing on your car and causing some of these Oddities.

Maybe a Teenie Tiny Touch Of Dilectric grease under the weight on that little plastic tab it rides on. And Dude I sold a Milk Crate full of Hei's at the Swap meet so Mabee youse go get one,(module) Hell your over budget anyhow.

I pulled the distributor cap tonight and went over things with a slightly more critical eye. First off, a dumb question - should the coil button in the center of the cap be recessed?

Second, I checked the shaft for wobble, and couldn't feel any, but there is quite a bit of gear lash. Is this normal?

https://www.youtube.com/embed/QiWMMF_0uAs

Lastly, these arrived.

My opinion: NO the button should be in contact with the rotor center metal strip/tang and maintain that contact with a spring pushing the button downward. Look at the rough surface that button has seen alot of arcing.

That distributor gear "lash" looks OK

That distributor cap is missing parts. There's usually a little spring loaded button in that part of the distributor cap that is not there in yours. Replace the damn distributor cap.

NO that one is Garbage, that Tip and Spring can be bought but then there may have been some cross arcing because of that, Just get a new rotor and cap

Now that we have seen your distributor cap hold off on replacing the module. The revenue part story pcap at it and go retest.

In reply to Dusterbd13 & GTXVette:

Haha! I'm glad I thought to look inside it and snap a pic!