3.0L Engine won't start

mikeinsac2003 · Jul 6, 2004

If you've read my previous posts you'll know that I just removed and reinstalled the head, manifold and riser. Only new part is manifold. Put it all back together and it won't start. Only thing that sounded wrong was every few cranks of the engine, I could hear back pressure coming back up through the carb. Is it possible that compressed air is not exiting through the exhaust port and instead releases back through the intake port when opened? If so, I'm assuming this isn't right...what should I do to fix it? Also, for some reason I couldn't find the order of fire for my distributor cap. Maybe i didn't look deep enough. When looking at the cap with the flat base on the bottom and the plugs. The poles would be at the 1, 4, 7 and 10 positions. So, in the same order, would the wires connect to the 2, 1, 4, 3 plugs?

Bondo · Jul 6, 2004

Re: 3.0L Engine won't start

Fireing order is 1, 3, 4, 2.......... You've got to find #1 TDC, to decide Where #1 pole is on the cap.............. The rotor turns Clockwise.......

Boatist · Jul 6, 2004

Re: 3.0L Engine won't start

Mike do not know why you started a new thread better to stay with one. After you adjusted the valves did you do a compression check???????? If you have a bad lifter or a lifter that does not not have full travel the way you adjusted your could have lots of valves not seating. If a intake valve is too tight and not seating gas and pressure will exit on the compression stroke back out the carb. Take 5 mimutes and do a conpression check. I will bet your valves are not adusted correctly.

mikeinsac2003 · Jul 7, 2004

Re: 3.0L Engine won't start

What is the easiest way to turn the crankshaft to align No. 1 to TDC? I've been reaching down and trying to turn it manually. (Not easy) Is there a tool or something that would help?

Bondo · Jul 7, 2004

Re: 3.0L Engine won't start

Take the Plugs out,+ Turn it using the Big Nut on the Alt......... You need a pretty Tight belt to do this........

Boatist · Jul 7, 2004

Re: 3.0L Engine won't start

As Bondo said take the plugs out. Do the compression check so you know where you stand. Squirt a shot of motor oil in each cylinder and bump the starter. My 3.0 turn very easy. I usually just grab the alternator fan with one hand put the other hand on belt to keep it tight and turn the alternator fan. Bondo idea is even better. Valve adjustment very important. Too loose and you will loose power because valve opens late and closes early. Also danger of hot gasses running thru a small gap can over heat the valve and cause it to burn or warp. Too tight and valve will stay open on the power stroke will have burning gas excapeing by valve and burn valve. Also since valve does not close it never touches the water cooled head to cool off so stary red hot until it fails.

mikeinsac2003 · Jul 8, 2004

Re: 3.0L Engine won't start

Thanks, Boatist. I appreciate the explanation. I decided to back up and loosen all the pushrods and start again. To be honest, part of my problem was that I thought that #4 fired before #3, so when I lined the rotor up to tighten the second sequence of valves, I was in the wrong place. After loosening and re-tightening the correct way, I was able to get compression readings between 145-150 on all cylinders. I didn't have any oil handy, so this was a 'dry' compression check. I noticed that the manual said compression should be 140. Is there any problem that my compression is higher? I believe that I understand from other posts that it is more important that there is not a big disparity between the cylinders. Didn't have time to cover back on and fire it up( I have 16 mo old twins), but I will get to it tomorrow...I hope. Also, Boatist, sorry about the new thread. I thought it would be too cumbersome to have people read all through all the other problems that needed to be resolved before getting to the latest. So, in that spirit.....I noticed yesterday before I pulled it apart again that when I was done turning the engine over fuel was still dripping down the throat of the carb and pooling below. While the boat was running before and I stopped it, the engine was hard to start and I could smell fuel. Hmmmm, kinda like it was flooded. It would appear that these are related, but maybe I am wrong. Could also be that the cylinder was full of water and just took some cranking to push it all out. Any thoughts?

Boatist · Jul 8, 2004

Re: 3.0L Engine won't start

Mike Good Job. 145 is great compression. Should be able to start anywhere above 120. Now all you need is a proper fuel mix and a spark at the right time. Firing order is 1-3-4-2, so take the distributor cap off and with the starter turn the motor and note which way rotor turns. Now take out number one plug and turn engine as before. Stick your thum in the number one spark plug hole and turn engine by hand as before. First compression will try and blow your thum out of the hole, but when you reach top dead center on the compression stroke and turn a little more is will try and suck your thum in. When you get to this point you know you are near top dead center on the compression stroke for number one. You can now use the crank timing mark and turn motor to line up with point engine should fire. I belive it is 4 to 8 degrees before top dead. Now pull the distribitor cap off and see if rotor is pointed at the number one spark wire. Also check and see if the points are open. If it is pointed at number one and the points are open then timing it is good enough to start engine. If points are not open loosen the distributor and turn until points are open. Points gap should be .018. Make sure still pointed at number one. Now you noted which way rotor turns with the starter. Going around the cap in that direction the next wire should be going to number 3 then 4 then 2 and back to one. While you have it all lined up take some white out and mark the crank index mark and the point you want to adjust to. While cranking the engine you can check with a timing light to double check. At cranking speeds can also check the points gap / dwell. Should be 31 to 34 degrees. Fuel can to hard to tell but if it does not start after you know you have fuel pumped up to the carb then pull a plug and see if it is wet with fuel. Take the plug away from the boat and put a match up to it. If it burn for a long time it is probably flooded and getting to much fuel. If it just burns for a short burst should be good. If it is dry and get no burn thennot getting fuel. If it is wet and does not burn then you have bad fuel or water getting in. About the new thread, You may be right but for me I read a lot of thread and comment when I think I may be able to help. Being I am over the hill they all kind of blend together over time, so I like to be able to scroll back up and see what has been done. Much easier for me when I do not hve to go back to a previous post. Other may disagree but either way not a big deal. Wish you the best of luck, and hope your get it fixed before Folsom get too low.

mikeinsac2003 · Jul 9, 2004

Re: 3.0L Engine won't start

Boatist, I didn't see your thread until just now. This afternoon, I put everything back together and it cranked right up. It was running very rough though. Put timing light on it after jumping white wires out of distributor and Shift Interupter as per manual. Before I did any adjustments, timing was at about 4 degrees after TDC. I adjusted distributor so that it was about 1 degree BTDC as per manual. When I removed jumps, advance took it to about 14 degrees BTDC just as manual stated. However, the engine still ran pretty rough. Also couldn't get it to idle below 1100 rpm, it would just die out when I used the idle screw below that level. At 1100, engine would also race a little to about 1300 and fade back. Temp, voltage and oil pressure guages all appeared to be in normal range. How should I troubleshoot this one? Also, I bought an Engine Analyzer from Sears, but I don't know where to connect the green clamp which should get a more accurate tach reading. Any thoughts?

Boatist · Jul 9, 2004

Re: 3.0L Engine won't start

Mike I sorry but do not know anything about engine analyzers. My Dwell/tach hooks to the minus side of the coil. I would think your instruction manual should tell you how to hook up and run simple test. I would hook up and check the dwell and make sure it is steady and at the right range. Now that you have it running can check a few simple things. First make sure you have no fuel leaks or gas smells. Turn your bildge blower on. Remove your flame arester and look in the the carb. Make sure the choke has opened and also look for any fuel dripping into the carb. If you see any then note when it drip in does the engine speed up or slow down. This may give you a clue if it is flooding or starving. If you have a way to squirt in more fuel safely do this and see if it picks up or stalls. Put a timing light on and make sure have a good spark on each plug wire. When the engine shuts off does it sound like it is missing on one cylinder or just in general bog down and die. If running on muff are you getting any smoke out the exhaust and if so what color???

mikeinsac2003 · Jul 26, 2004

Re: 3.0L Engine won't start

Right above the center mounting bolt on the intake/exhaust manifold there is a threaded hole that it appears air is being sucked into the intake manifold. If I put my finger on it, the engine performance changes. Should this hole have a plug in it? I thought all the air came down through the carb. There was no plug that came with the kit and I already threw away the old manifold to compare it to.

ron7000 · Jul 26, 2004

Re: 3.0L Engine won't start

Originally posted by mikeinsac2003: Right above the center mounting bolt on the intake/exhaust manifold there is a threaded hole that it appears air is being sucked into the intake manifold. If I put my finger on it, the engine performance changes. Should this hole have a plug in it?

yup! that's where you'd put a vacuum guage to for diagnostics. It should have a pipe thread plug in it. any leakage there and your whole air/fuel mix will be thrown off and the engine will run super lean. get a pipe plug, 3/8 i believe, and use either teflon tape or a good rtv. On the 3.0L, mine anyway which is 2002 and has the mercrapcarb, the idle mixture screws should be initially set at 1.25 turns open, and the throttle set screw two turns down after contacting the cam which will open the butterflies in the carb. Once the engine's warm, you can adjust the idle mixture screw and throttle set screw to get good idle. "The poles would be at the 1, 4, 7, 10 positions, would the wires connect to the 2, 1, 4, 3 plugs" Correct firing order is 1 3 4 2. According to your statement, you have cylinders 3 & 4 crossed.

3.0L Engine won't start

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