no start

[ahhhhchoooo]

merc 454 trs drive, not sure model number as block was changed in the past and there is no number, not too sure about the year either. Carbed, Thunderbolt IV with module on riser. While the engine was winterized i did the manifolds and risers, cap and rotor. Now it won't start and is acting as if the timing is off (popping and hissing back out of the carb). I double checked all the wires and they were correct. I even removed the number one plug to make sure that when the piston was at T.D.C. the rotor was pointing at the correct wire in the cap. I then did that for number 3 and 5 as well and they all were at T.D.C. in the correct locations at the rotor. I checked to make sure the engine was the correct rotation (standard) and it is and the rotor moves the correct way giving it a firing order of 1-8-4-3-6-5-7-2. I was just curious what test i should do next, should i be testing out the sensor in the dist, the module on the riser, or look towards compression testing? I've winterized this plenty of times before with no problems, i'm just hoping that has nothing to do with it. thanks in advance.

 

[Don S]

Re: no start

Check the rotor, make sure it has 8 gaps in the metal ring not 6. They are only a dash number different and if stuck in the wrong parts bin will get you the wrong one.

 

[Fishermark]

Re: no start

You mention replacing the cap and rotor. You don't need to remove the distributor to do that of course.... but did you? If so, it is possible you have it 180 degrees out. Just a thought.

 

[whywhyzed]

Re: no start

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[ahhhhchoooo]

Re: no start

i will double check that the rotor is correct although it did come in a set with the cap (maybe i'll just throw in a whole new cap and rotor again to make sure i didn't get a deffective part). We didn't remove the distributor to do the cap and rotor and we were deffinatly doing T.D.C. compression stroke. i'll post how it all came out.

 

[Bondo]

Re: no start

Now it won't start and is acting as if the timing is off (popping and hissing back out of the carb).

Ayuh,....

Did you try rotating the Dist. to see if it got Better, or Worse,..??

Are you getting Fuel to where it's gotta be,..??

 

[whywhyzed]

Re: no start

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[ahhhhchoooo]

Re: no start

Bond-o, I am getting fuel up to the carb. I took off the flame arrestor and pumped it, I can see fuel going in. I thought maybe i had flooded it so i tried to start with full throttle and open choke but a fireball came out of the carb so i figured that had nothing to do with it. As far as rotating the distributor, when i put, for example, #1 piston at T.D.C. the rotor is pointing to the correct "tower" on the cap so i don't think it is so far off to cause the engine to not start.

whywhyzed, i do have a timing light but haven't used it yet. Will using it without the engine being able to start give me more diagnostic help?

Also, i still haven't gotten to do what i said i was going to do before, like check the rotor and put in a new cap and rotor to see if it will help. Thanks for all the help, i'll be most likely doing the rotor and everything tomorrow.

 

[Don S]

Re: no start

You don't have to replace the cap and rotor if they are alright, all I said was check the rotor to make sure it's the right one.
If you had the wrong cap on it, you would have had two to many plug wires

 

[Bondo]

Re: no start

Bond-o, I am getting fuel up to the carb. I took off the flame arrestor and pumped it, I can see fuel going in. I thought maybe i had flooded it so i tried to start with full throttle and open choke but a fireball came out of the carb so i figured that had nothing to do with it. As far as rotating the distributor, when i put, for example, #1 piston at T.D.C. the rotor is pointing to the correct "tower" on the cap so i don't think it is so far off to cause the engine to not start.

That alone says the Timing is Not right......

 

[whywhyzed]

Re: no start

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[Coors]

Re: no start

Bond-o, I am getting fuel up to the carb. I took off the flame arrestor and pumped it, I can see fuel going in. I thought maybe i had flooded it so i tried to start with full throttle and open choke but a fireball came out of the carb so i figured that had nothing to do with it. As far as rotating the distributor, when i put, for example, #1 piston at T.D.C. the rotor is pointing to the correct "tower" on the cap so i don't think it is so far off to cause the engine to not start.

whywhyzed, i do have a timing light but haven't used it yet. Will using it without the engine being able to start give me more diagnostic help?

Also, i still haven't gotten to do what i said i was going to do before, like check the rotor and put in a new cap and rotor to see if it will help. Thanks for all the help, i'll be most likely doing the rotor and everything tomorrow.

That is waaay advanced, or plug wires are on wrong.

 

[ahhhhchoooo]

Re: no start

ok, update.
Here is what i did, i'll just start at the beginning.
1) check the rotor, it had the correct amount of gaps on the sensor wheel.
2) check timing, the mark was dead on with the number one plug wire.The knob on the timing light was set at 0, not sure if that matters.
3) threw in another new cap and rotor.
4) loosened the dist. and turned it slightly even though it was reading that it was dead on.

after doing all this it actually started. I only let it run for a second though because it had no hose hooked up as i didn't think it would actually run. Tomorrow i will hook up the hose, start it up and let it run and see exactly where the timing is reading at now.

I've never seen one not start because the timing is so slightly off (i didn't rotate the distributor that much, it was within an eight of a turn).

The only thing i could think of was (this is a little hard for me to describe) that the original cap had the number one plug wire from the engine going to number 2 on the cap then continued its normal firing order as number 2 on the cap being number 1 on the engine. So when i put the new cap on i might have missed the slight offset of the plug wires on the cap and i put them acording to the numbers on the new cap (1 on cap to 1 on engine instead of 2 on cap to 1 on engine). That doesn't explain though why the number one plug was dead on with the timing light, but i'll have to look at it tomorrow while its actually running.
Thanks for the help everyone , i'll update tomorrow again.

 

[Maclin]

Re: no start

I have been in after other "mechanics" that did not know how to orient the distributor and put it bakc in wrong then moved the wires around on the cap to make up for it. If you went by the book instead of one wire at a time from the other cap then you may have run into this same problem. I do not know how many clockings the distributor shaft has on that one. On some engines it is just a slot so it is either in right or 180 out. Others have a hexagonal or octogonal shaft and there are many more ways for it to be off.

 

[whywhyzed]

Re: no start

[....

 

[Bt Doctur]

Re: no start

when you replaced the wires did you notice 2 firing orders on the cap?
one is std, other is reversed large vs small numbers
1 8 4 3 6 5 7 2
1 2 7 5 6 3 4 8

 

[Fishermark]

Re: no start

Your cap doesn't have a set number 1 - the cap doesn't care what wire is called number 1...

So when i put the new cap on i might have missed the slight offset of the plug wires on the cap and i put them acording to the numbers on the new cap

Even if your new cap has numbers identifying #1, etc, you should have put the wires back on the same terminals if you didn't move the distributor. That's your problem. Once you start it tomorrow, you should be able to put it back in time with your light. But it sounds like the problem started by moving your wires one spot over to the "correct" spot.