HELP! Slant 6 just doesn't want to go!

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69DartCustom

69DartCustom

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Hey guys, Sorry if I start ranting but it's my first post. I'm restoring a 1969 Dart Custom with a slant 6 225 and I just can't get it running properly and was hoping someone here could maybe help me out. The car was stored in a barn for just over a decade when I brought it home in the fall of 2009. At that time the carburetor, the points, the rotor, the plugs and wires, coil, fuel pump and distributor cap had all been changed and I disconnected the old fuel line from the tank and ran a line into a jerrycan to play it safe. At that time the car was movable but not running great. Since I had brought it home I had not been able to move the car for a couple of years because I put it up on jack stands and redid all the undercarriage, differential, fuel lines and brake lines (I work slow) but I still ran it time to time. Then one time when I tried to start it up it would not go at all. Turns out the nylon drive gear on the distributor had cracked and broke. I replaced it and put the distributor back in and it was running again (still running rough). When it came time to start it up for the first time this spring it wouldn't even turn over, after finding a short in the starter motor, I replaced it as well at the starter relay and it started up but was still not running quite right. I finally got the car down onto it's tires and when I go to put the car in gear it quit on me. So then I thought it's got to be a timing issue. Started the car up and hooked up the timing light and it was far too advanced. I must have been off a tooth from when I changed the drive gear on the distributor. I found TDC of cylinder one and spent quite a bit of time trying to get it right. I pulled the distributor again and marked where the rotor will be just before the contacts open (which is where the plugs should be) put the distributor back in and ran the wires accordingly and now I'm lucky to get it to start. When it does start it runs for maybe 2 minutes and then quits. It even quits when I give it full throttle! I'm baffled, the only other thing I can think of is a fuel problem? Maybe the carb float is sticking? I've been reading the 1969 dodge service manual and there isn't much in there to help me with this one. Any thoughts or ideas would be greatly appreciated!
 
Does it restart after it dies? If it restarts does it run for another 2 minutes or longer/shorter? If it does restart how does it run after the restart?

I have seen a car do the whole runs poorly after storage deal before and the cause was a mouse had filled the exhaust pipe solid with debris. It would run until the backpressure choked out the engine.
 
Sometimes it restarts sometimes it doesn't, when it does it might be for 30 seconds or so. You're right about the exhaust and I forgot to mention that. Something did burrow in the pipe so it was removed from the muffler back (the muffler was packed). When the car was running for it's two minutes there was nothing else coming out the exhaust, and it seemed pretty clear.
 
Most likely a fuel problem. Try spraying starter fluid down the throat when it starts to die to confirm. For spark, install an in-line spark indicator (cheap at HF). Clip a voltmeter from coil+ to engine ground and see if you lose power when it dies. Before spending a lot of time fooling with points, consider upgrading to HEI ignition or Pertronix Ignitor II.
 
When you replaced the soft fuel hoses, the one at the front and the one underneath coming off the sending unit, did you use injector hose or just regular old fuel line? Use injector hose, because the ethanol in new gas eats the rubber of fuel line and turns it to jelly. Just throwing this out there as something not so obvious to check.
 
Sounds like a problem my Scamp had when I got it. I took it'd run for a few minutes then die, no matter what I tried. I figured it was a fuel issue so I put on a clear fuel filter just before the carb and I started the car and let it run awhile, after a few minutes I watched as the fuel level in the filter dropped and sure enough, the engine sputtered and died. I worked and worked trying to figure out the problem but couldn't I didn't know as much about engines then as I do now (still not near enough) so I took it to a mechanic. Long story short, he fixed it. Said it was a diaphragm located under the distributor? Said they get brittle over time and tear and that's what was wrong.. Any affirmation on this would be great! Good luck!
 
Wow!! long read for me but I think it could be one thing..... you do know the bottom of your distributor has a adjusting area also If you have it running and the distributor is close to the mid range of adjustment you are good there

Know if you have it going as far as you can.. one way.. and it run's but will not run good if you pull it back a bit .... your bottom adjustment is off maybe ... pull the distributor out and adjust the bottom so you can get more advance or bring the timing down.. Just a thought ... I hope this threads ends well
 
Except there is no diaphram under the distributor.
There's one inside the advance canister on the side of the distributor, but it wouldn't make it run out of fuel.


I think the original poster has a plugged up fuel filter.
 
TrailBeast said:
Except there is no diaphram under the distributor.
There's one inside the advance canister on the side of the distributor, but it wouldn't make it run out of fuel.


I think the original poster has a plugged up fuel filter.
Click to expand...

Thank you TrailBeast :cheers: I missed that part, his tank is obviously nasty and plugging up filters and Carb :thumleft:
 
Does sound like it starves.
Fuel filters wont catch everything. There could be quite a bit of trash collecting right behind the fuel inlet/needle and seat. I think they would stick open so it would be flooding the bowl when fuel is coming through.
 
Does it happen only when hot outside? Slants have a common problem with the fuel boiling in the supply line to the carb, though doesn't usually bother our Canadian brothers. There are several fixes w/ photos here. If you get a clear fuel filter, you can see when it goes to vapor. Don't be alarmed if you see some air or vapor in the fuel filter since that seems to be common. Some people have installed a filter w/ a vapor return port on the top and run a tube back to the gas tank, but that probably isn't necessary to fix the problem.
 
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