Ok guys here is the deal. I have put a new intake and exhaust manifold, new carburator, new distributor with electric ignition, re-built fuel pump, new exhaust, new plugs, new wiring harness, and new others.
I have been trying to get it started and found out I had no spark. I then replaced the coil and now have good spark.
It started up and ran for about 40 seconds and then stalled. I have tapped the new carb a few times too. At first I thought I was not getting fuel. WRONG I pulled the fuel line and the pump is pumping??? I tryed a bit of starting fluid and nothing. Checked spark again and got good spark??
Any suggestions? This motor ran good before all this it just had a cracked exhaust manifold.. Its got me baffled. I have re checked the distributor timing to make sure I had it at top dead center of #1 and it is right. Also it started and ran and when it ran it sounded good...
HELP!~
Avatar = My father-in-law Roy E Coates stopping at home before his first tour in Vietnam. Fresh out of boot camp of the 101st airborn. By his side are his two younger brothers and his little sister. One has to love the 60's with those tiger skin vests. I miss him much..
54' M37CDN,56' R2 "Argyle", 52' M42 project, WC51,M51A2,M52A2,M816,M35 Curtiss Wright gasser,M35A2 "Sandbox Slayer", M35A2 tank truck,M109A2,M1009,M56B1,and to many trailers to list.
Vacuum leak? Spray intake and carb gasket seams with WD40 or other spray oil and see what you get. The oil will be thick enough to temporarily close up any leaks. Spraying when running will often pinpoint a leak by a change in RPM.
If it flooded out for whatever reason then pulling the plugs and drying the electrode ends out with a propane torch will often get things going again. The heat drys and the open flame burns off any residual gas. Of course, don't do this procedure around any fuel sources like the carb, fuel pump, etc.
How did you check for spark? Did you pull the wire off and check it with a checker or did you use an inductive checker with the wire still connected to the spark plug? Just because you get spark from the plug wire does not mean the plugs are sparking. The plugs may be fouled. The gap may be jumped. Did you pull them out and check them? Try checking the plugs.
I pulled the plug and turned it over. I had a nice blue spark. These are also new plugs but I will re-check the gap to make sure. That electric ignitor puts out some good clean spark. No more points.
I drained the battery so I am charging them now and will try some of the mentioned things tomarrow.
Avatar = My father-in-law Roy E Coates stopping at home before his first tour in Vietnam. Fresh out of boot camp of the 101st airborn. By his side are his two younger brothers and his little sister. One has to love the 60's with those tiger skin vests. I miss him much..
54' M37CDN,56' R2 "Argyle", 52' M42 project, WC51,M51A2,M52A2,M816,M35 Curtiss Wright gasser,M35A2 "Sandbox Slayer", M35A2 tank truck,M109A2,M1009,M56B1,and to many trailers to list.
Bear with me on this one; can't remember right now if Unimogs have accelerator pumps or not. With the engine shut down and air cleaner horn off you should be able to see down the carb throat and see if you get fuel spray when you work the throttle linkage. Fuel to the carb float bowl is not going to do any good if it can't get past a plugged jet. Do this check ONLY with the engine off. Past experience has taught me how flammable mustaches are in cases of an ill-timed back-fire. (The smell of burning mustache was bad enough but it was my buddy beating out the flames that put me in the E.R.)
Most Accelerator pumps have their own jets separate from the primary jets. It will tell you if the carb is getting fuel though. Remember, you need three things for an engine to run. Spark, compression, and fuel. If you have spark and the carb is giving fuel to the engine then it has to be compression. Pour a small amount of fuel down the carb then replace the aircleaner. This part is real important. Hold the throttle all the way open and try to start it. If it fires then check the carb. Something might have came loose that is clogging the intake ports to the primary jets. If it does not start or at least sputter like it is starting then I would check compression. If the compression is good then recheck timing. It has to be one of the items mentioned above. I would start over and check everything since it is obviously something elusive.
Make sure the distributer is set for top dead center on the compression stroke (both valves closed) Next make sure the spark continues the whole time the engine is cranking (loose wire) Check the firing order of the plug wires. Make sure when distributer is at top dead center on the compression stroke the rotor button is at the terminal of the first cylinder in the firing order. Check for cracks in the distributor cap. You might check all the other plugs to make sure they are not wet/flooded. If so, heat up with heat gun or torch to dry. Make sure what is going into carb is actually gasoline. Water might have gotten in tank, you never know.
Ok gods of all things OD.. Here is the situation on the 251 Canadian. Still would not run, had a friend over that has 5 M37's that all run and knows a little bit about them. We ran through all the normal checks. Good spark, got fuel,timing set right,plug wires right,and so on. Decided it may be the vaccum thing Charles at M-series rebuild mentioned to me awhil back. I had to just forget about the truck for a bit out of frustration,anyway compression check = #1 45lbs, #2-43 lbs, #3-NOTHING?? #4- 45lb's, #5-45lb's,and #6 54 lb's.
Exhaust valve on #3 is stuck! Whats the best way to un-stick it? I took a piece of hardwood and tapped very gently and nothing. Is there a good product that I can put down the cylinder to eat away bad gas residue? Do I have to pull the head? Next step please?
Could this be the reason it will not run again? Not enough vacuum for fuel adimizing? Uhhh...It seems like it would fire if even just run like pooooo... How are these compression readings? Are they to low?
Avatar = My father-in-law Roy E Coates stopping at home before his first tour in Vietnam. Fresh out of boot camp of the 101st airborn. By his side are his two younger brothers and his little sister. One has to love the 60's with those tiger skin vests. I miss him much..
54' M37CDN,56' R2 "Argyle", 52' M42 project, WC51,M51A2,M52A2,M816,M35 Curtiss Wright gasser,M35A2 "Sandbox Slayer", M35A2 tank truck,M109A2,M1009,M56B1,and to many trailers to list.
The stuck valve will cause the engine to not run. Kroil is THE way to get it unstuck. Get some and be patient in how it works. It's slow but effective. Trying to run the truck with a stuck valve is only begging for disaster.
DR is right penetrating oil will work its magic over time. Many moons ago we use to use something called Berryman's Chemtool to clean the varnish off of parts and valves and guides. I don't know if they are still in business. If for some reason the penetrating oil does not do the job you also try grabbing the spring retainer and move it back and forth while spraying more oil. I am guessing this is a flat head engine, you might also try very gently prying down on the retainer with one of those curved pry bars. Don't pry to hard you run the risk of bending the valve. If this is an overhead valve engine there are a couple of other things you might be able to do.
trying to get the 251 running again?
