Troubleshooting my FE

[Gaz64]

Originally Posted by CompFi

pix of cap, rotor and springs:

Looks new, but dry as, typical MSD.
Pull the rotor, and apply some moly spray grease to the moving points in the advance mechanism.
Leaving it dry like that causes the mechanism to grind itself into microscopic dust that rusts up inside, and guess where it goes, all over the magnetic pickup.

And your XP series carburetor does not have any vacuum ports on the throttle body, for vacuum brakes, vacuum advance, and vacuum accessories.

[CompFi]

Originally Posted by 55312

Quinton Brothers. Williston.

PM sent

[sunman]

Street Fire is a cheap non USA product sold by or at best assembled in USA by MSD

The whale oil or whatever was used in the caps in the power supply section of the pcb has dried out

It’s the easiest part to change and I suggest a different brand no matter what due to past history of failure

I’m not saying this is your real problem just something I’d change first

[CompFi]

Originally Posted by sunman

Street Fire is a cheap non USA product sold by or at best assembled in USA by MSD

The whale oil or whatever was used in the caps in the power supply section of the pcb has dried out

It’s the easiest part to change and I suggest a different brand no matter what due to past history of failure

I’m not saying this is your real problem just something I’d change first

Should I confirm proper functionality? Or maybe you are suggesting replace it proactively even if functioning properly now? As in, if not failing yet, it will.

If that is the recommendation, what is the preferred replacement here?

[patrickt]

Originally Posted by CompFi

Should I confirm proper functionality? Or maybe you are suggesting replace it proactively even if functioning properly now? As in, if not failing yet, it will.

If you were in the local Cobra club we would slap on an extra MSD 6AL if our first slapping of the Holley 750 Vac Secondary didn't cure the problem. Remember, there are two clues to your problem: 1) Your car originally ran great, but now is running like crap; and 2) An abundance of heat accompanied that change in performance.

Now, you could have more than one thing wrong with your car, but probably not. But maybe. Not everything that could go bad on your engine is going to cause both symptoms. But if you think really generally, the problem is likely to be 1) Too much air in your fuel air mixture; or 2) The spark is firing at the wrong time. Possible problem #1 could have the air coming in through the carb, or from somewhere else; and problem #2 could have a couple of different causes. Now, it could also be a bizarre combination of something else, but those are two most likely scenarios.

Remember everyone on here is a diagnostic genius, so we'll eventually stumble on the solution.

[sunman]

Use a hairdryer and heat the Street Fire up
See what happens
That’s the way to check for heat induced electronic problems
Cold spray too

[CompFi]

Originally Posted by patrickt

Remember, there are two clues to your problem: 1) Your car originally ran great, but now is running like crap; and 2) An abundance of heat accompanied that change in performance.

Now, you could have more than one thing wrong with your car, but probably not. But maybe. Not everything that could go bad on your engine is going to cause both symptoms. But if you think really generally, the problem is likely to be 1) Too much air in your fuel air mixture; or 2) The spark is firing at the wrong time. Possible problem #1 could have the air coming in through the carb, or from somewhere else; and problem #2 could have a couple of different causes. Now, it could also be a bizarre combination of something else, but those are two most likely scenarios.

Great synopsis. Starting with the two clues that appeared together.

I have been concentrating on eliminating the carb as an obvious culprit of #1. First, the rebuild by a trusted source. And now, I need to complete the tuning per Holley instructions. Taking my time here, trying to be methodical. I will report back as soon as I can confirm completion of the Holley tuning instructions.

In the meantime, I do appreciate all of the suggestions and feedback.

[sunman]

Lot of people said “distributor looks good”
Really?
The magnetic pickup could be bad
You can’t tell by looking

[patrickt]

Originally Posted by sunman

Lot of people said “distributor looks good”
Really?
The magnetic pickup could be bad
You can’t tell by looking

That is true... but it's doubtful it would cause the engine to begin overheating. But we can put it on the check list.

[sunman]

I think it’s the box
Early firing causes backfiring and late causes overheating
The multi spark is out of control
Dave said the carb is good
Just a guess

[CompFi]

Originally Posted by sunman

I think it’s the box
Early firing causes backfiring and late causes overheating
The multi spark is out of control
Dave said the carb is good
Just a guess

Sunman - appreciate the guidance here. Definitely got my attention that I need to focus on the box.

One thing i should clarify about the backfire thru the carb. That is NEW. As in, happened once this past weekend right after I re-installed the carb following Dave's re-build and I gave it gas to check the throttle linkage etc. Definitely got my attention Could be that the one backfire resulted from me not yet completing the Holley tuning instructions. Then again, could be the box. Just wanted to clarify that the backfire was new in case I was unclear about that.

[eschaider]

Originally Posted by CompFi

Ed, no argument from me on the tuning problem. It is the solution that is proving elusive. Though Billy Andrews could have probably resolved this issue blind-folded....

But not as if I have been unwilling to throw $$ at it by deferring to experts. Once this issue began last Summer, I started to ask around for recommendations for a local shop. I was hesitant, but I followed the consensus feedback and took the car to a local shop claiming to specialize in 60s muscle cars. I didnt balk at the sizable quote for time on the dyno etc to tune the carb. Thing is, the shop never put the car on the dyno. They fiddled with the carb etc. I still got hit with a sizable bill, more than your estimate. And I didnt even get any time on the dyno.

So, believe me. I take your point. My incremental troubleshooting is far from ideal. At best, this is Plan C. Which is why I am so grateful to all here for the guidance. And patience. Hopefully something here also helps the next person that finds themselves in my situation.

I'm sorry, but I'm not surprised to hear that, Brian. The number of "tuners" who actually understand the process and how to go about it with a Holley is few and getting smaller at an alarming pace. I wish I could pull a rabbit out of a hat and say go here, but I don't have any credible suggestions.

There are a number of quite good engine builders who frequent the CC site here. I believe some of them have dynamometers they use to tune and provide a final QA check prior to shipping an engine to their customers.

The one I have in mind is Brent Lykins. I think, but don't know if he has a dyno. At the very least, he probably could get your Holley into the ballpark. If, as I suspect, he has or has access to a dyno, he would be my first suggestion for a proper resolution to the problem. He is quite good and has been very engaging and easy to talk to on the site here. I think he is a good bet and definitely worth a shot.

Here is a link to his website; https://lykinsmotorsports.com/engines

His website pics show finished engines being run on a dyno, so he does have or have access to one. His phone number is (502) 759-1431, which sounds like Northern Kentucky. That's quite a way from VT, but it might well be worth the effort. I am not sure you will find the knowledge to successfully address this problem in VT.

[patrickt]

You can go only go so far bench-setting a carb for a performance engine that has an intake manifold that doesn't even sit level. Your floats are never going to be right until you set them when they're on the engine. That's not a big deal. You used to be able to just pull into an Esso and they'd set them for you while you chatted with Mabel behind the counter....

[CompFi]

Originally Posted by eschaider

I'm sorry, but I'm not surprised to hear that, Brian.

Appreciate the insights here, Ed. And certainly seen many helpful recommendations from Brett here on the forum. And lots of happy customers too. In fact, I watched Brett's video on setting the curve for the distributor. Tremendously informative for someone like me. Sure do wish I could poke my head into his shop, I just might do that some day.

But, as Patrick points out, I need to tune my carb on my engine. And I will probably make some mistakes on my initial attempts. But good to know that I can rely on plenty of expertise here on the forum from folks willing to help. Again, greatly appreciated.

[eschaider]

I'm glad to be able to help, Brian.

This item I am about to show you is not a go-out-and-buy-one-right-now sort of thing, but it is an in case something goes wrong with your current distributor sort of thing.

This unit is the definitive distributor/ignition tuning solution for carbureted engines. It gives you a fully programmable advance curve capability that mimics the ignition maps used by EFI systems — but is for carbs. It also has a digital engine kill switch/theft preventioin capability that cannot be defeated without replacing the distributor. You control it with a Bluetooth app on your phone.

Here is the link =>https://progressionignition.com

[767Jockey]

MSD boxes work well when they're working, but they're notoriously unreliable. I carry a spare in the trunk of my car. Whether yours is bad or not, I'd recommend you pick up another to carry with you. I put quality plugs (I used this kit with heavier duty plugs on the power and ground lines - https://www.amazon.com/Weather-Pack-...=A39ZZJ3OT79TI ) on each lead so that if I have to swap it out it's a 5 minute procedure rather than running new wires each time I need to swap it. It also makes troubleshooting in cases like this easy - I can very easily just swap the MSD box over to the other MSD box to confirm or eliminate the box as the source of any issue I may be having. Not only are the MSD boxes unreliable, but their failure can drive you nuts when trying to diagnose because the failures manifest themselves in many different ways.

I guess that's all a long winded way to say buy another box and swap it in to see if it helps. It won't cost much and I'd highly recommend that you carry a spare anyway so the money will need to be spent either way. It's also not a bad idea to pick up a spare magnetic pickup for the distributor to carry with you, as they're equally prone to failure as well. MSD stuff works really well but their products are sadly not very reliable.

[CompFi]

Thanks Jockey.

I have already learned plenty from this experience and feedback like yours.

Top of that list is the reliability of the box, or lack thereof. After I complete the Holley's instructions for tuning the carb, I will turn my attention to the box.

And good advice to carry the spare box, so I will incur the expense either way. Pretty sure that Sunman would agree.

P.S. Truly appreciate all the feedback from everyone. Currently working thru the initial tune of the carb. Painstakingly slowly, both due to my inexperience and some work conflicts. So, it might be a while before I update the thread with any progress. But either way, I will continue to update the thread.

[kevins2]

I also carry a spare MSD box in the trunk. Mine is mounted under the glove box so I cut a couple of Velcro straps to strap the spare to the mounted one. Makes it easy to simply plug it in and go. Also carry a spare coil.

Kevin

[Blue66]

CompFi how far are you from Freedom , NH ?

[CompFi]

Originally Posted by Blue66

CompFi how far are you from Freedom , NH ?

Apologies Dan - completely missed your post. I am in Burlington so about 3.5 hours to Freedom. Basically due east across all of VT and NH. No doubt a beautiful drive, but not a short one.....