Timing Problems

[lucky7's]

I have a 2002 Mercrusier 6.2 mpi. I had to pull one of the heads off to have the valves worked(burned two intake valves) and put the thing back together and i think im having problems getting the timing right. I used scribe marks when i pulled the distributer out and did not rotate the engine after the distributer was pulled out. I put the thing back in just like it was and now it wont start. I followed the service manual exactly what it said. It fires some and then it has trouble turning over at one point like a cylinder is firing too soon because when i disconnect the coil wire it turns over great. it pops everny now and then out of the intake too.. Timing must be off .. Ive even tried aligning the timing tab at #1 TDC and the set the rotor tang to the little notch in the distributer housing just like it shows in the service manual and it does the exact same thing.. Compression is great on all cylinders. I am really stumped on this one!! Anyone know about these 6.2 mpi's. Help PLZ!!!

 

[Viking...]

Re: Timing Problems

Both the camshaft and crankshaft gears have to be aligned according to your engine specs (ie: timing marks pointing at each other - cam at 6 o'clock, crank at 12 o'clock).
Assuming they are correct, the distributor has to be aligned also (it's possible to have it out by 180 degrees on most engines, so be sure you have it correct!).

The engine should start if the distributor is set to zero advance, but will be sluggish to start.

If all of these things are correct, you can now fine tune the timing by using a strobe-light. Don't forget to remove and plug any vacuum lines attached to the distributor (if applicable).

Engine specs will dictate how many degrees BTDC (before top-dead center), which you can pick up on the flywheel markings. Rotating the distributor slightly clockwise/counterclockwise will dial in this setting.

I know these are generalizations, but they are true for all four-stroke gasoline engines.

Hope that helps.

 

[P 0 P E Y E]

Re: Timing Problems

When in doubt check your math, rotate engine to get Top dead center no 1 piston on the compression stroke...actually about 9 degrees BTC.

Put the distributor in and look at where the rotor is pointed This is where you will connect no. 1 spark plug wire.

Trace each wire to ensure the fireing order is proper.

If the engine was apart for a long time, sometimes the lifters loose all their oil and you need to prime the oil system to get the lifters filled up...this can be done with an old distributor with the timing gear removed. If some or most of the lifters do not have oil, it will drastically effect valve timing.

 

[lucky7's]

Re: Timing Problems

Yea all of that is correct.. Already tried 180 out and it blew some flames out the intake. There is no vacuum advance on this engine, it is computer comtrolled and there is only one timing mark.

 

[P 0 P E Y E]

Re: Timing Problems

Timing card should be on the hormonic balance and an indicator card on the timing chain cover.

Sounds like you have all the steps and are just missing one or have one backwards.

Slow down and re check evey step.

 

[lucky7's]

Re: Timing Problems

Engine was only apart for 3 weeks. and all wires are hooked up properly.

 

[P 0 P E Y E]

Re: Timing Problems

take spark plug out of number 1 hole, bump engine to assure both valves are closed and piston is coming up on it's compression stroke.

Rotor should point to this point on the cap...look which way rotor turns..follow other wires to ensure fire order is good.

 

[Viking...]

Re: Timing Problems

Slow down and re check evey step.

Exactly what I was thinking.

Pay particular attention to the ignition wires.
Don't assume the distributor turns clockwise (or counter)...you might have the wires in the correct firing order, but they could be backwards.

Not that I've ever done anything like that...just something I heard...somewhere...from someone...once... :redface:

 

[lucky7's]

Re: Timing Problems

There is no timing card on this engine there is only on notch to line up. Don S. confirmed this earlier on a thread i sent because i coundnt find the timing card. He sent me a diagram showing the timing marker there is one plastic notch on the cover plate

 

[Don S]

Re: Timing Problems

Seems all your replies will work great with a points distributor and a carbed engine. But I strongly suggest you go back to your OEM manual and follow the steps for a 6.2 MPI engine with and ECM.
If you have had the distributor out, there is a section in the OEM manual on how to install it. Trust me, there are no degree marks on the other the 0 on the timing chain cover and 1 mark on the dampner. That's all you need.

 

[P 0 P E Y E]

Re: Timing Problems

I know your Paine. I have been there.

Here is a question, is the boat a twin screw?

Would mean that one is left hand 18436572 and other engine is Right hand rotation 27553481

 

[lucky7's]

Re: Timing Problems

No way to hook them up backwards. The wire plugs on the distributer are not oriented in a circle instead all even cylinders are on the left and all odd cylinders are on the right of the distrubuter cap and the are all numbered.

 

[P 0 P E Y E]

Re: Timing Problems

Seems all your replies will work great with a points distributor and a carbed engine. But I strongly suggest you go back to your OEM manual and follow the steps for a 6.2 MPI engine with and ECM.
If you have had the distributor out, there is a section in the OEM manual on how to install it. Trust me, there are no degree marks on the other the 0 on the timing chain cover and 1 mark on the dampner. That's all you need.

Right you are sir, I am what I yam....an old cs 720 a and AL 868 man from way back

 

[lucky7's]

Re: Timing Problems

Yea i did that. I have the factory service manual. Line up the notch to #1 TDC and the there is a tab like an arrow in the distributer housing that the rotor lines up to. It shows a picture diagram to do it. And i have it lined up perfectly.

 

[MikDee]

Re: Timing Problems

I have a 2002 Mercrusier 6.2 mpi. I had to pull one of the heads off to have the valves worked(burned two intake valves) and put the thing back together and i think im having problems getting the timing right. I used scribe marks when i pulled the distributer out and did not rotate the engine after the distributer was pulled out. I put the thing back in just like it was and now it wont start. I followed the service manual exactly what it said. It fires some and then it has trouble turning over at one point like a cylinder is firing too soon because when i disconnect the coil wire it turns over great. it pops everny now and then out of the intake too.. Timing must be off .. Ive even tried aligning the timing tab at #1 TDC and the set the rotor tang to the little notch in the distributer housing just like it shows in the service manual and it does the exact same thing.. Compression is great on all cylinders. I am really stumped on this one!! Anyone know about these 6.2 mpi's. Help PLZ!!!

Did you have the engine on TDC of #1, when you marked, & pulled out the distributor? You have to be on TDC for Cylinder #1 to adjust some of the valves on that head, and then Crank it over 1 turn clockwise, to adjust the rest of the valves on that head. The service manual would tell you which valves you can adjust, with the engine on TDC of Cyl #1, and the remainder of the valves that you can adjust with the other piston thats at TDC, after the one revoultion clockwise. (it might be Cyl #6, like the small block Chevy?). It's a 4cycle engine, so it takes two revolutons of the crank, for every 1 revoultion of the camshaft, & distributor.Then you can set your igniton timing.

 

[lucky7's]

Re: Timing Problems

Ive followed the procedure 3 times what it says in the manual. Its a pretty simple procedure. But something is still not right

 

[lucky7's]

Re: Timing Problems

Yes you are correct I adjusted the valves that way. It is either no.1 firing position or no.6 firing position.. The rotor tang must be aligned on the no1. firing position which there is a notch in the rotor housing to line up to

 

[P 0 P E Y E]

Re: Timing Problems

Start the process over

Do not assume anything

Treat it as your first time

Double check each and every step

Bring your ole lady out to the boat and make it a verbal presentation.

You are repeating one or more steps with a slight error. By talking to some one as you do it, you might just find or smell your brain fart

 

[MikDee]

Re: Timing Problems

Did you set your valves at zero lash? that's where I like to put them, then start the engine, and do a running adjustment, setting them 1/2 turn down from zero lash when done, this way I'm not jamming any of the valves. I've seen too many times when a static cold valve adjustment creates problems.

 

[MikDee]

Re: Timing Problems

Or, maybe you were on TDC of #6, and adjusted the valves for #1, and vice versa?

If your sure your distributor is in right, the rotor should be pointing to #1, when you're adjusting the valves for #1, and pointing to #6, when adjusting the valves for #6.