Randomly lose power when driving

[Zed Head]

1 hour ago, CaptainMajestic said:

brand new electric fuel pump, cleaned out tank with the vapor chamber and no carbon canister, custom made 5/16" copper nickle fuel and return lines, and a 3/16" breather (if i remember correctly).

Don't mean to keep picking at you for more info but the time factor is important.  How long can you drive before the problem happens?  How long (days, weeks, months) did it run fine before things went bad?  Is the pump a high quality pump or a cheap aftermarket pump?  You might have a pump that's dying.  Not uncommon, and they do overheat as they go bad.

The tachometer needle is the best indicator of module problems.  

[CaptainMajestic]

Hi @Zed Head I've put about 500 miles on the car before I started seeing this issue in the first place. The runtime before seems pretty random, I've had as little as 5 min and as high as 30 min while debugging. What's a good way to place a fuel gauge that I can see while running? Guessing electronic?

[Zed Head]

Many people are able to leave the hood partially open and hang the gauge out of the opening.  Or, if it takes a few minutes to completely die you can jump out and take a look when it happens.  It can take some work but if you see zero pressure when it happens, that's a big clue.  Or if you see full pressure.  Process of elimination.

[siteunseen]

I screwed 3/8s barb on a cheap gauge from Lowe's pool supplies department. I believe I used some 5/16" hose for a tight fit then put a zip tye or maybe a small worm gear clamp? Worked out great.

I found a big rotted hole under the intake.

 

[siteunseen]

I forgot my whole point. ?

If you have a fuel pressure gauge you can see while driving it will tell you more. My fuel pressure went down the more I used the motor. It was sucking in a bunch of unmetered air through that hole.

[CaptainMajestic]

Side question, has anyone here run aftermarket transistor ignition units? I hear they are finicky at temp

[Zed Head]

There are a lot of "aftermarket" ignition systems. Crane, MSD, 123, Pertronix,,,   They're not all the same.  The answer would be yes.  Pick one and you'll get something, or describe what you're looking for and someone can suggest one.

[CaptainMajestic]

3 minutes ago, Zed Head said:

There are a lot of "aftermarket" ignition systems. Crane, MSD, 123, Pertronix,,,   They're not all the same.  The answer would be yes.  Pick one and you'll get something, or describe what you're looking for and someone can suggest one.

Cool, does the wiring line up to the connectors on these? Or do I have to roll my own?

[Zed Head]

There are really only five connections to worry about.  Ignition systems are easy to get wired up correctly.  But the different types can have different problems even when wired correctly. There isn't one that"s obviously better than the others.  You have to decide what you want from it before you can pick one.

[SteveJ]

It's not too difficult to replace the TIU with an HEI. Search around this site.

[wheee!]

I have one in the classifieds for sale... [emoji51]

[CaptainMajestic]

Thanks everyone, turns out it was in fact a clogged fuel pump filter. I swapped it out with a new one and the problem disappeared. I need to figure out where the sediment is coming from as the fuel tank was recently restored and cleaned.

 

Thanks!

-Michael