351 wont fire up ...

[rob935]

over the off season i had both heads skimmed on my 351 and replaced head gaskets etc. and torqued to specs , tried to start it up this weekend but with no luck at all . its turning over fine and seems to want to fire up but just doesnt start , i didnt remove the distributer when taking the heads off so the timing shouldnt need adjustment ?? any ideas guys thanks .

[1redTA]

When diagnosing a motor that won't start, check for fuel air and spark
when you find out what is or isn't missing it will be easier to Internet diagnose

[rob935]

its getting fuel and air but will have to check the spark to be sure .

[thatsmrmastercraft]

Originally Posted by rob935

its getting fuel and air but will have to check the spark to be sure .

You can use a timing light to check for spark. Its especially easy if you are working by yourself. Just put the inductive lead over a plug wire and tape or wire the timing light trigger in and look for the flash of the timing light.

Should be something simple. Good luck.

[Laurel_Lake_Skier]

If the engine ran without problems prior to the work, I'd suggest starting with looking at things that may have changed while you were in the process of removing and replacing the heads. A compression check (it is possible the heads are not sealing or that by shaving the heads your valves may not be closing due to a need for shorter push rods or shims under the rockers) , vacuum test (if you have a leak between the intake and heads or carb and intake) and double check of fuel going to the carb would all be good starting points.

[markismm]

I agree with the post above. Check first gas, then air, and finally spark. If you are receiveing these three items you should be getting some fire. If you have tried shooting starting fluid directly into the carb and you are getting no fire check the spark. While you can check it with the timing light, you can also check it by simply removing a plug and grounding the electrode and visually seeing if you are getting a spark. No spark most likely means you have a bad coil or have the cold wired improperly. You may want to check all of your wiring first.

[Laurel_Lake_Skier]

In addition to the earlier post, be sure to double check the firing order.....its pretty easy to to mix up a couple of plug wires when everything goes back together and that of course will make it tough to fire the engine.

[rob935]

thanks guys , i have checked all the wiring and its all connected correctly and plug leads are in the right order too , will need to double check for spark ....just wondering if its down to having the heads skimmed (valves not closing ) as i was very carefull to put it all back the way it was disassembled , i just presumed it would start up without any adjustment ???

[CantRepeat]

How did you adjust the valves? If you have not done so, maybe the intake valves are not opening thus not letting fuel in. When you say it's getting fuel is that because you see it come out of squirters on the carb or are you pulling a plug and it's wet with fuel?

[1redTA]

How much did the machine shop take off the heads? If the heads were skimmed to much to need pushrods the intake probally needs some attention too.

First ground a spark plug and make sure it is getting spark. As mentioned do you smell gas on your plugs? G/L