[69 SS396]

Brought my car home sunday from the painter, about 30 miles and she ran great the whole way.

Started it up the next morning and it ran great.

Over the next couple days I installed headers and new pypes exhaust system and changed the trans fluid and filter.

Had to jack up the driver side of the engine to install the header and replaced the broken motor mount while I had it off.

Started it up and doesnt want to run, spits and pops and backfires and will sometimes just die like I shut off the key.

I pulled the dist cap off to check if I cracked it and its perfect. Put it back on fired it up and she ran great. Let it run for a couple minutes and shut it off.

Tried to start it again and runs like carp again.

Any suggestions? Did my dist module take a carp?

Engine is a 1969 350 horse 396 with a Jegs electronic dist. A/C delco plugs, Accel 8mm wires.

 

[WaterDawg]

Intermittant problems are tough. Did the new headers and pipes increase the airflow into the carb so that it needs re-jetting?

 

[goodcruiser]

Check all of the wiring that you could possibly have disturbed,look for loose terminals and or broken wires(give them a tug to see if they stretch). Especially check the wiring going to the ignition system.If your still using the old glass style fuses I have seen the filaments crack and get intermittant connections,pull the fuses and use an ohmeter, connect it to each end and tap the fuse several times to see if it is still connected inside.
We're guessing here but maybe one of the ideas that are presented here will help.

 

[horseman]

Is there ANY chance something wound up in the exhaust system? Did yiu properly put a rag in it to stop anything getting into it and then forget? Is there some packaging left in it? Any blockage could cause these symptoms

 

[ohiohoss]

might be the carb my elco was doing close to the same thing i swapped the carb ''edelbrock 600cfm'' to a brand new matching carb and it runs like brand new. the crap they put in the gas these days tears our carbs up inside

 

[Sasquatch]

Check your spark plug wires,especially on the side you had to jack up. Some may have pulled loose from the plug boots ( but not all the way out ). Also,did you disconnect your spark plug wires while installing the headers and possibly get a couple of them crossed ? Had a similar problem a few years back. Engine would run fine around town,but when I jumped on the freeway it would start cutting out,popping and farting. It drove me nuts for about a week until I decided to recheck my plug wire placement and found two of them to be crossed. ...................... :neutral2:

 

[69 SS396]

Thanks for all the replies.

Update: took the module out had it tested tests good ohm tested all the plug wires not sure what the spec is for ohms but all were aprox the same at 1.1 to 1.45 k ohms dist cap tested good went around the firing order several times and is correct. No grounds or other wires pulled loose. Nothing in the exhaust.

Started it and it ran fine for about a minute then started its sh&t again. Sputtering and popping out the exhaust and intake.

 

[69 SS396]

Update #2

Swapped out my carb for the old one, ran good for about 30 seconds then (raspberry noise)

I'm missing something obvious. It cant run so good before then this carpy now.

 

[JJLT1]

:dontknow:headers on a bbc,,leads to vapor lock about 50% of the time,,re-rout/insulate the fuel line to the pump..:texas:

 

[69 SS396]

It will only run for about 30 seconds good before it poops out.

Thats not long enough for vapor lock.

Just put in new plugs in case I had cracked some while installing them.

Runs crisp and clean for 30 seconds then........

Gotta be the dist module even though it tested good.

 

[WaterDawg]

Hhhmm, being non ECM, doesn't leave alot more things to check...
I'm thinking dist. mod too. Had one do the same thing. Eventually fried for good.
Turned out a loose wire to the dist underneath. Felt tight but had intermittent
contact. Maybe........

 

[69 SS396]

There doesnt seem to be any rhyme or reason as to when those things go out.:dontknow:

 

[goodcruiser]

There is usually a reason when this kind of thing happens and usually it leads back to what ever you were working on before it started acting up.Go back over everything you did to one step at a time and think of what you did at each stage step by step.This includes every vacuum hose you bumped, pushed or removed end to end of each hose.

 

[ccc]

sounds like the module is getting hot and shutting down or your coil is bad shutting down the module. an ignition module will do really stup crap when they are going out.do you have the window style dist cap or are you running a hei variant?

 

[69 SS396]

GM HEI from Jegs. It was cheap but better than the points dizzy.

 

[ccc]

put a module in it and see .did you do a harness shake test,grab and shake the harness while it idles and see if it does anything.i will asume it has vacuum advance.if so check the pickup coil with with an ohm meter while moveing the advance plate .i have seen the wires break from the coil rotating durring advance and retard motion

 

[horseman]

The painter didn't express a strong interest in your elky did he???:let_it_all_out: How long was he in control of it without you around???

 

[DONE DEAL DONNY]

Check the battery wire to the dist. real good, it can be plugged in but the wires push out just barely making contact.
Donny

 

[Skandolis]

sounds a lot like a coil heating up, even hei coils can go bad, a lot of times they will start and run fine for a bit, then when they get hot.....................................

 

[HKDUP87]

GM HEI from Jegs. It was cheap but better than the points dizzy.

Just had the exact problem the last thing I did before giving up was change the control module under the cap and she purrrrs. I Think almost every sensor, carb., dist. cap/rotor, plugs and wires etc. still wouldn't start unless I checked everything again and again kept running rough when it did start .
CONTROL MODULE $49.00 FIX IT AFTER A FEW HUNDRED. ALSO CHECK FOR A MELTED PLUG WIRE IF THERE RUNNING DOWN THE BACK OF THE FIREWALL.
:let_it_all_out: