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Motor firing opposite direction


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I just put a new long block in my 2008 Malibu VLX with a monsoon 340 in it. I have it all back together and am having an issue. When I crank the motor over, it fires in the opposite direction of the start, fighting the starter and causing a draw and a few times has even spun over a few times the other way if released the key quickly enough. Have tried rotating timing 180 degrees several times and verified firing order over and over. Any ideas on what else could be causing this? Also verified that the firing order for the new short block purchased from marine engine depot is the same as the factory monsoon 340. Thanks for any help

Edited by TannerN
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12 minutes ago, robbennett said:

Did you use the right distributor? I think it needs to be an actual indmar one. Also no chance you used a counter rotation engine is there? 

The distributor is the one off the old motor so it is correct. I made sure to have the correct rotation motor ordered but I guess it’s a possibility I received the wrong one. But in this case, wouldn’t the specified firing order for the replacement motor be different than the factory firing order?

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9 minutes ago, COOP said:

When you ordered the motor did they ask about engine rotation? When we get rebuilds one of the questions they ask is if the motor is standard rotation or not. 

I got a standard rotation motor but I guess they could have sent the wrong one. In this case though, would the firing order specified for the new motor not be different from the firing order of the original motor? They match according to both sets of specs I found

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It sound like the timing is just advanced too far.

If you want to check if you're motor has the reverse rotation camshaft, disconnect the ignition, turn it over with the starter, if air is being sucked down the intake it's normal, if it's pushing air out the intake it's reverse.

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It is pushing air out of exhaust and sucking in the intake when turning over. We have tried retarding the timing as far as possible but there is not much room with the intake. When the timing is turned 180, the motor will not even attempt to start. When the timing is advanced, it does fire more severely opposite however

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The distributor gear only wants to go in at two spots, 180 degrees opposite each other. If this is not supposed to be the case, this is most likely the issue

Edited by TannerN
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11 minutes ago, TannerN said:

The distributor gear only wants to go in at two spots, 180 degrees opposite each other. If this is not supposed to be the case, this is most likely the issue

It's been many years but, Doesn't the oil pump drive off the bottom of the distributor? I haven't been in any newer engines like this but you used to have a situation where the dist was a tooth off because the drive in the bottom of the dist was seating on the oil pump drive and not allowing the dist to seat correctly. We would have to take a long screwdriver down the dist hole and rotate the oil pump drive a little to allow the dist to drop in on the correct tooth. 

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11 minutes ago, TannerN said:

The distributor gear only wants to go in at two spots, 180 degrees opposite each other. If this is not supposed to be the case, this is most likely the issue

That is only because of the oil pump drive rod.  You have to turn it to the proper position with a screwdriver before installing the distributor  it is not how you determine proper distributor position

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Just now, jmack said:

Do you have a timing light?

Yes I do.  I believe I can find TDC by pulling the valve cover and then get the distributor set close enough to the correct timing using the flat head screwdriver trick on the oil pump drive rod to get it to run then use the timing light to get exact

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5 minutes ago, TannerN said:

Yes I do.  I believe I can find TDC by pulling the valve cover and then get the distributor set close enough to the correct timing using the flat head screwdriver trick on the oil pump drive rod to get it to run then use the timing light to get exact

Just be aware that you are tring to set the rotor/distributor gear at the correct  ttooth, you cannot make up even 1 tooth off by timing with the body. 

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12 minutes ago, TannerN said:

Yes I do.  I believe I can find TDC by pulling the valve cover and then get the distributor set close enough to the correct timing using the flat head screwdriver trick on the oil pump drive rod to get it to run then use the timing light to get exact

You don't need to pull the valve cover.  There is a mark on the balancer that will tell you where TDC is you can pull spark plug #1 and put your finger over it when rotating to TDC to tell if you are on the compression stroke or if you need to give it one more rotation

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Got it running and let it idle on the hose for a minute. Found TDC using the thumb trick and the marking on the harmonic balancer. I was 2 teeth off prior to adjusting the oil pump with the flat head. Thanks for the help guys! 

Edited by TannerN
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17 minutes ago, TannerN said:

Got it running and let it idle on the hose for a minute. Found TDC using the thumb trick and the marking on the harmonic balancer. I was 2 teeth off prior to adjusting the oil pump with the flat head. Thanks for the help guys! 

Now you need to have the dealer set the final timing, unless you have diacom.  You can't set timing on a computer controlled vortec with a timing. Light.  You need to be able to read the cam angle. 

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