Help please. 360 off dyno, now won't start in car...

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DartThis74

DartThis74

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I finally installed after 3 years my newly rebuilt 360 in my 74 dart sport. I had the engine tuned up and on the dyno a few months ago and was running very well. NOW I finally have everything hooked up in the car, while in between the dyno shop and installing it i definitely made sure not to move or change a single thing so it would hopefully start up just fine. Today, that didn't happen at all, when the engine starts it is extremely rough idle to the point it dies, that's if it can even stay idling. If you give gas it might back fire and die. What could be the problem here, I'm at a loss with what it could be. The distributor never moved from the dyno shop and all plug wires are in their locations. Could it be bad gas? The gas in the tank is pretty old. I will say that the carb had to come off to install the motor I'm sure nothing was moved on that either.



Thanks for any help !!

-Aaron
 
If the fuel in the tank is old drain it out. You can also hook up a small fuel can to test.
 
Well it could be sucking air. Check; PCV system, brake booster,Base gasket, Power valve if a backfire occured.
Oh yeah, take a fuel sample. If the fuel is not clear,or ever so slightly yellow, get rid of it.
If it is orange or red it is way past done.That red stuff is hard to light and smokes pretty bad. Pour a few CCs on the floor or in a metal pot and see what I mean. Dont try it with clear gas if you value your eyebrows!
 
Update: I hooked up a gas can straight to the fuel pump and that worked very well the engine did run much better, BUT it is having hard time idling. I have to keep my foot on the pedal to give it slight more gas to keep it running, but if I press to hard it cuts out and dies. Any suggestions ?
 
DartThis74 said:
Update: I hooked up a gas can straight to the fuel pump and that worked very well the engine did run much better, BUT it is having hard time idling. I have to keep my foot on the pedal to give it slight more gas to keep it running, but if I press to hard it cuts out and dies. Any suggestions ?
Click to expand...

Clogged air bleeds will cause this
 
It pumps a good shot of gas if I press the throttle down, so I know there is fuel getting through the carb fine. But it's acting like it isn't...
 
I assume you had the distributor cap on when you installed the engine? If so I'd be making sure I didn't bump the cap and knock it loose or crack it.
 
is it dripping fuel from the boosters after running? does it have a choke? electric or mechanical fuel pump? what kind of carburetor? new / old fuel filter?
 
AJ I'll check on that.

Dubob : cap with wires connected were removed during installation. Installed cap to distributor and connect wires to spark plugs after engine was dropped in.
 
73abodee: it has an electric choke, mechanical fuel pump, Holley 750cfm Model 3310. Filter is new at fuel pump and fuel inlet is from summit that has fuel pressure gauge with filter built in. Fuel pressure is between 5-8 psi I believe it read.
 
How long did it sit? Carb drained of fuel? Maybe gummed up. You re--checked the cap? Might have gotten it 'cocked' and damaged the rotor. You SURE the dist has not moved? Tried to twist it?

I do hope you got the dyno crew to give you timing settings.
 
I will get back to the car in a few days to check the suggestions out. But as far as vacuum lines go. I only have the one going from the valve cover (pcv) to the carb and one from the carb to the vacuum port on the distributor. Is there another one I'm missing that is important that I just didn't think to hook up that could be causing any issues? Thanks everyone!
 
The car runs!! I brought the dyno guy over and turns out the timing was off along with some other tiny factors thrown in. An msd ignition was used to run my engine at his shop, and I'm running an orange box which is a different timing. The engine now sounds like a monster.
 
Yeehaw!!
Well I guess we will have to add that tidbit to our memory banks, for next time.

Hey,waitaminute!
A dyno guy that makes house calls? And 3 years later? That guy needs a plug. Good on him.
 
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