motor shutting off while driving
 

Well, with all my other issues, this is a new one..........had the car out today for about 5 minutes the motor just shut down............took about a few tries to get it to run............went back home, nothing seems off............took out again for about 20 minutes, same issue , shut off while driving.............its never did this before.......the fuel filters are fairly new, about 2 yrs old...........car starts up on the 3 try, about 30 seconds, runs great after that............took it home..............any ideas on what to look for.


About the only thing i did was used some different gas then i usually use..........dont think its some heat related issue............its never done this in the 25 yrs i owned the car.

Rich

What does it have for a distributor, points, HEI?
Take it out for a local drive again with a buddy and with you take your timing light.

When it dies again check with the light if it has spark .

Steve, great question...........i have a msd box with a msd coil............had this distributor set up by shaker 455 on the forum few years back, will have to check with him on what i got going.

Will take a pic with the cap of tomorrow, it that will help..

Rich

As usual with this car, wont do the same thing twice in a row..............threw in $20 of shell gas, which i normally use............drove around 30 minutes, no issues, went up to about 60-70 few times................mostly drove around the block figuring my wife can only push it a few blocks..........thats a joke, she can push more than a few blocks.

So no idea, why its acting up, yesterday i had it on a 90 mile ride...........no issues.................problem now im scared to take it on the freeway, when it shuts off, not a good thing.

If it helps any, oil pressure always at 60..............water temp 172-174...................car never overheats.

Rich

MSD boxes do go bad sometimes. If you dont identify a different issue, might be a good idea to buy a backup box. Then if it strands you all you have to do is pop that new one in.

Let me guess: Blaster 2 coil.

NASCAR and other racing series often use switches so they can engage a second MSD box and/or coil when the first one fails in the middle of a race. MSD themselves sell the switches.

Which doesn't promote confidence in their products.

I've had them fail both ways--MSD 5 box on a vehicle that wouldn't start intermittently; when it does start it runs reliably until I shut it off. Or, vehicle with MSD 6T died and never re-started until the spark-box was removed.

My MSD coil was purchased years before they shifted production out of the country.

A lot of us never want to deal with adjusting or changing points so we convert to an electronic ignition of some sort.

Myself I’d rather make a small adjustment or occasionally replace points than deal with the headache of trying to figure out what failed and the consequences of that.

At the very least use points to trigger the MSD so you can jumper the MSD out of the system when there’s a problem.

Give me a GM HEI any day over any aftermarket electronic distributor.

I like carburetors too. :)

So you have a points type Dizzy that is triggering the MSD by points?

Steve, will take the cap off today and take a pic................will try to get hold of shaker 455 and see what he did setting up this distributor, i lost some of the paperwork on that.

The coil is a msd blaster ss

Not sure whats going on, the car did die twice, but restarted after a couple tries..........then like i said, ran perfect for a half hour.

Want to get this straighten out quick...........not the best feeling in the world when it shuts off and your fighting with the steering, not to mention the brakes.

Rich

Has the cars fuel supply system other than the pump been replaced?
Like the rubber jumper above the tank from the sender to the fuel line?
Are any sections of the steel fuel line showing rust?

Where the two days when the motor cut out hotter then the day you put Sunoco in the car?

Steve, the fuel pump was replaced two years ago............also the filter before the tripower..............will look at the rubber jumper today.

Will have to look at the fuel lines for any rust............

When i said the motor died , it was twice in the same day...........the first time a few blocks from my house, restarted it and drove around for about 15-20 minutes, died again.........took it home to see if i could find anything loose...........then i went and put in the new gas , then drove for a half hour with no issues.

Temp has been about the same the last couple days, 80-82 ish..............but have had the car out in the 90"s with no issues either.

I was under the impression if you have some bad gas, it will stumble some, but not shut off like i turned the key while driving, the two times it shut off i was going about 30 mph, running great, then nothing.......

Rich

There are many things to check besides what has been posted.

With the motor stone cold start it and let it run for ten seconds.
Then turn it off, remove the air cleaner from the middle carb and look down in it while working the throttle lever and make note of the accelerator pump shot.
It should be strong with little movement.

Should the motor cut out on you again do this same check but first note if the bores of the carb are wet with fuel.
If so then your float level is too high and or the fuel is boiling off making for a too rich condition.

If that’s not the case then work the throttle lever to see if the pump shot is still as good as when you checked it with the motor cold.

If not then you have a fuel delivery issue to work out.

When the motor has cut out on you and you have gotten it restarted does the exh smell rich?

Does it blow a puff of black smoke and take a few seconds to get back to a good idle?

Usually an intermittent shut off like this, as in completely dies but then restarts & runs ok after, is not related to things like a float being too high, or heat when its only 80 degrees out, or putting in a partial tank of different gas... as mentioned that usually causes stumble or cutting out, not a complete shut off like the key was turned off but then runs fine afterwards....

It definitely sounds more ignition related, whether thats the msd box/coil, or power connection/wires to the dist, or something inside the dist like the pick up coil etc. I had a pickup coil cause intermittent dying a couple times for a couple days, then it just shut off like I turned off the key and never ran again until I tracked it down pretty quick & replaced the pickup coil.
I would check all wiring related to the ignition, there are some basic ohm tests you can do on the coil & the pickup coil too. But rusted fuel lines on a garage kept restored car or the accelerator pump are most likely not the issue... always good to check & verify all those things in general, but they probably aren't causing the engine to just die, then restart fine & run fine, IMO.

Hows the leak doin?

Cliff R talks about this all the time. His extensive experience here claims these aftermarket ignition systems are made overseas and most of them are junk. It seems the question is when it will fail, not if. Hard to beat a points system unless they get wet as Cliff talks about.

So far there hasn’t been a clarification of exactly what distributor you’re using.

Okay so Jeff (Shaker 455) who’s one of the best distributor and carburetor guys set it up, but again exactly what do you have ?

People are practically bending over backwards here to help you so how about we start by spelling out exactly what we’re dealing with here.

I’ll make one comment on the MSD box location, those boxes don’t like heat so mounting it anywhere inside the engine compartment especially on the firewall isn’t doing you any favors.

I used to run an ancient MSD6A box on my GTO bracket car triggered by a stock points distributor. When I got the car from my friend back in 1989 that MSD box might have been 2 years old, it was mounted under the dash near the glovebox.

I drove that car to work every day in 1990 for about 11k miles commuting, removed the ‘69 RAIII 400/DNE 5-speed and installed a ‘71 455 HO/TH400 then bracket raced the car between 1993 and 2002 with never an issue.

I always kept the 2 little jumper wires that MSD supplied in the glovebox but never needed them. I’ll say also it was fun watching several of my competitors scrambling to replace failed HEI modules during the race day, I’m sure at least one of them couldn’t make it to the lanes giving me the win in that round.

Agreed!
It’s very annoying when it gets to the point as in this string of post where the OP makes you wonder if he is intentionally side stepping providing answers.

Sounds like a fuel tank venting [or lack there of] issue.

Wow, tough crowd today..........not side stepping anything here, like i said, trying to get hold of Jeff to see excately what he did to the distributor..............its a stock distributor, found these pics that i had of it..........so when i get hold of jeff, i can pass that info on.

Dont know if these pics will help anyone of your guys.

Rich

Here’s the problem with most of the posters here asking for help diagnosing a problem with their cars.

They write all kinds of things describing what’s going on but give absolutely zero information regarding what fuel system, ignition system, any pertinent engine specs and just about anything else.

So these threads turn into a 20 questions from those trying to pry information out of the original poster to help them solve their issues.

Tough crowd ?

Not tough enough.

Don’t expect people to have to go back through your previous postings to see what you have on your car.

Help us help you.

This is not an attack on you Rich but it’s frustrating seeing you either ignoring or overlooking a simple request from Steve who’s really going out of his way to offer a solution for your problem.

Cant figure out where all that red dust is from in pics.