OMC Won't start

[nkever]

Hi there, I have a 5.0(302 ford)OMC cobra engine. My compression is 120 pretty much across the board(one down to 105, one down to 100). I have spark, gas(even tried starting fluid). As I turn it over, it seems like it is not pulling the fuel down into the motor. I can get a backfire if I set the timing out to far, but I can not get it to fire. Any Idia's?

 

[Don S]

Re: OMC Won't start

The engine will not "Pull" fuel into it while cranking, you have to pump the throttle to operate the accelerator pump to squirt fuel into the engine.<br />But, if it won't start on starting fluid either then you have another problem.<br />First I would suggest you get rid of the starting fluid before you destroy the engine.<br />Since you are getting spark, and it won't start and backfires, I would suspect timing, or even plug wires out of order. Did you have all the plug wires removed? Or the distributor removed?<br />You can check your firing order. Get the engine up on #1 TDC and check where the rotor is pointing in the distributor and that you are not 180° out, then check the wires are in the correct order. The firing order is the same as the picture below.<br /><br />

 

[cmyers_uk]

Re: OMC Won't start

I had a problem exactly like this and spend all day trying to fix it, it was only at dusk that I saw I had a spark at the boot on the coil. I took the ht lead off cleaned the connections and it fired first time. So basically I was getting a spark but not one strong enough.<br /><br />So if all the things Don suggests dont work try turning it over in the dark and see if you are leaking current.

 

[nkever]

Re: OMC Won't start

I see the distributor rotation in your picture is counterclockwise. Mine rotates the other way. but other than that, my firing order looks right. I will double check it though. Thanks

 

[Don S]

Re: OMC Won't start

I just noticed that my firing order is for a 94 to 96 model 302, and you never stated a year. If you have an 86 to 93, the firing order would be 1-5-4-2-6-3-7-8.<br />You better check that rotation, all Fords rotate that direction, and I don't recall any counter rotating 302's.<br />Is the distributor on the front of the engine?

 

[Boatin Bob]

Re: OMC Won't start

Don...not trying to confuse things here but in my Clymers, it shows 1989 up there is a 5.0 and 5.0 HO, I'm assuming the HO is high output and probably has a 4bbl carb? Anyway the book shows the firing order for the 5.0 as you said the second time 1-5-4-2-6-3-7-8 but it shows the 5.0 HO as 1-3-7-2-6-5-4-8 same as the 5.8 and both are counter clockwise. I guess we need to know the year or model number to really answer the question.

 

[nkever]

Re: OMC Won't start

It is a 90 OMC in a bayliner 2050, however the distributor is turning clockwise. The firing order is on the flame arrestor. it is 1-3-7-2-6-5-4-8. This is a boat I picked up and the history goes as follows, The owner hooked up the battery backwards and cooked a few things. The starter, alternator...ect. The gas was bad so I drained the tank and refilled it. I installed an Ignitor and a flame thrower coil(aftermarket electronic ignition conversion) all is well with that, I have great spark at the plugs. If you are positive the distributor should be spinning Counterclockwise, perhaps the starter is wrong, I will look into it. Thanks

 

[Don S]

Re: OMC Won't start

Has the engine ever been ran since the starter was changed????

 

[nkever]

Re: OMC Won't start

No, not that I know of. Still thinking about the bad gas, there is a spin on filter/water seperator that is full of it. and the carb is dumping fuel and flooding the motor. I am going to rebuild it and change the filter. Thanks and I will keep you posted.

 

[nkever]

Re: OMC Won't start

Yep, the starter was turning the wrong way. Mabye the old owner got it from a car parts store. Who knows. Thanks for your help guys.

 

[Bondo]

Re: OMC Won't start

Yep, the starter was turning the wrong way.

Ayuh..............<br />That's 1 Sure Way to mess-up the Firing Order.................