Engine not starting

[thistle3585]

How about this? Can I be flooding it? Maybe its too rich or I'm just drowning the plugs so that they can't work. If I were to disconnect the fuel line should it start using starter fluid in the carb?

 

[TroyaCantrell]

I hate to say it but often when you take it to a mechanic they are not always as much of an expert as we would like them to be.

Especially when it comes to troubleshooting difficult issues. I have had this problem recently with two vehicles on three occasions. It is very aggravating when you pay them a ton of money and then are no smarter then you are.

That is quite a list if replacement parts. It is possible that one would still be bad though. Dead in the box, that always seems to happen to me. Was the ignition control new or junk yard?

Have you checked spark on every cylinder?

One question is still on the voltage. Have you checked voltage at different locations. Battery, alternator, ignition, coil, starter, it should be up close to that 14.4 ideally. Test with the key off, key on, key in start position. You will need help for that one . If you have had to crank and crank and don't recharge the battery it will be low.

How about the alternator and voltage regulator, not sure if yours is internal or not.

If you want to eliminate the compression as an issue do a good test. Get a good gauge, the screw in type, follow the instructions for that gauge and test each cylinder and you will know. Due them all twice! Holding your hand over the carb is not a good compression test.

One last thought and no offense just have to ask, the firing order is correct right. I assume since a qualified mechanic installed the new distributor that he would have looked at it but double check. It doesn't sound like that is the issues but something easy to verify.

I like the idea of using just the starter fluid. You know you have spark but not how strong it is. Should be good considering the all the parts you listed but the starter fluid is so combustible that it will work with lower spark. Pull the plugs, clean and dry them and reinstall first. What would that tell us though? We know it has fuel (flooding) but not the quality of the fuel or the pressure. I don't see fuel filter on your list of things replaced either.

You could clamp off the fuel line and see if it starts on fluid and the release the clamp.

I still keep going back to it ran, moved, died though.

 

[thistle3585]

I used the screw in type compression gauge and went through every cylinder. Everything replaced was done with new components. Yes, I have checked the battery, the coil and the plugs. New filters on either side of fuel pump. Firing order is correct. I have not done anything with alternator/voltage regulator.

I went back to the electrical repair shop and talked with the owner. He asked to hold on to it longer and he'd take a look at it himself.

 

[grozam]

Have you tried a different gas tank with known good fuel? You can run a rubber fuel hose to a gas can with good fuel to test it.

 

[thistle3585]

Have you tried a different gas tank with known good fuel? You can run a rubber fuel hose to a gas can with good fuel to test it.

No, and I have had my suspicions about bad gas but I've also tried starting fluid without luck. I will try using an alternate container this weekend. You never know. I'd think it would at least try to fire with the starting fluid. The question is "Why wont it fire when its got fuel and spark?" My only guess is too much fuel or not enough spark. I don't know that it would be a mechanical issue.

 

[BrockGrimes]

I've had one that wouldn't fire on starter fluid.

When you installed new grounds did you clean the contact surfaces, block, etc.?
With all the electrical swaps are all the parts stock replacement parts? Any hop-ups like HEI, hotter coil?

This problem your having reminds me of one I've seen before but I can't recall the solution. I'll dig around and see what I can find, it may take me sometime so don't wait on me.

 

[thistle3585]

I've had one that wouldn't fire on starter fluid.

When you installed new grounds did you clean the contact surfaces, block, etc.?
With all the electrical swaps are all the parts stock replacement parts? Any hop-ups like HEI, hotter coil?

This problem your having reminds me of one I've seen before but I can't recall the solution. I'll dig around and see what I can find, it may take me sometime so don't wait on me.

Yes, I cleaned them all with a wire brush to bare metal. The only non-stock item I installed was an ignition coil with an internal resistor but I also replaced the resistor wire and it checked out fine with a meter. It also started once with the new coil.

 

[tarry99]

Yes, I cleaned them all with a wire brush to bare metal. The only non-stock item I installed was an ignition coil with an internal resistor but I also replaced the resistor wire and it checked out fine with a meter. It also started once with the new coil.

WOW...........I can't believe your having so much problems........First off I would verify that your motor is in time. Pull the number one spark plug , if you have a compression gauge with a removal line take it apart and screw the spark plug end into the cylinder head , hold your finger over the open end and then slowly turn the motor over. When you can feel pressure pushing your finger off the end "STOP" look at your timing marks on the crankshaft and front cover and it should be close to the Top Dead Center marks. If you need to move the crank a little to line up the marks do so with a breaker bar manually using the large bolt in the front of the crank..........now pull your distributor cap off........is the rotor pointing to the #1 plug position on the cap?..............if it is thats good!

Next I would bypass the Ignition and hook a wire directly to the coil from the positive side of the battery.......of course if it starts the only way to kill it would be via taking the wire off and or hold the brakes on and kill it with the clutch.

If you suspect fuel take off the line from the tank to your fuel pump and plug it off........you can either fashion a short line from the fuel pump in port to a small can of clean fuel watching out that you keep it away from the hot exhaust or any sparks.........or you can fill the float bowls via the float vents and let it run off of what is in the Carb...............in either case this process will give you a path to start eliminating all the normal things that occur when a motor will not start. One at a time.................

And I agree with Dave, normally low compression is not the issue.

 

[BusaDave9]

I have replaced the following over the last two months.
Steering column which would include the ignition switch
Battery with cables
ground wires
solenoid
ignition control module
ignition coil
distributor
spark plugs
spark plug wires
fuel pump
rebuilt starter
new carb gaskets

Was the steering column or any other of these parts replaced BEFORE the problem started. If so they could be the problem.

 

[thistle3585]

Tarry99,
I have already done those things except for bypassing the fuel tank. No luck.

BusaDave,
A month or so before the problem started I had replaced the steering column and steering shaft, rebuilt the starter, replaced the rear main seal, oil pan gasket, valve cover gasket, new horn and both belts. I drove it daily for several weeks before this issue arose.

Some new information came to light.... I mentioned that the mechanic got it going after having replaced the distributor and reset the timing about a week ago at which time I drove it a hundred yards before it died. Well, it seems that they hadn't tightened down the distributor after setting it so it most likely shifted while driving it. They came back and reset the distributor and redid the timing but still no start. They went through that process and getting it top dead center several times with no luck.

 

[tarry99]

Tarry99,
I have already done those things except for bypassing the fuel tank. No luck.



thistle,
With all due respect.....the internal combustion engine is quite simple.
When you eliminate computers , sensors and nonessential wiring and take any motor back to the basic's of just Timing of Ignition ,camshaft & crank , correct spark delivery in time and energy and a simple fuel delivery process there is not a motor that will not run when all those simple things are in the proper sequence.

Who ever has looked at your engine is either not qualified or is missing something.

Without any reservation if that vehicle was in my shop here it would either be running in 30 minutes or diagnosed with the correct problem.

 

[Old Dog]

Tarry99,


Some new information came to light.... I mentioned that the mechanic got it going after having replaced the distributor and reset the timing about a week ago at which time I drove it a hundred yards before it died. Well, it seems that they hadn't tightened down the distributor after setting it so it most likely shifted while driving it. They came back and reset the distributor and redid the timing but still no start. They went through that process and getting it top dead center several times with no luck.

This really makes me wonder if it really is in time. Have YOU checked it or are you just taking there word that it is close to being in time.

 

[thistle3585]

Olddog,
I have checked it and its right on the nose. Four different mechanics, one being an electrician, have worked on this Jeep. The one guy that did get it going had it for two days and put a new fuel pump and distributor in it and did not charge me because he felt bad that it didn't solve the problem when he thought it would. He didn't even charge me for the parts. His shop is next door to my office, he has offered any tool in his shop for me to use. He has had several other friends that are mechanics come by and look at it. I can't count how many times he, or someone else, has redone the timing on it. Believe me, I want to be able to say that the guys that have looked at it are hacks. It is now at the electricians, which is on the other side of my office building, and I had a chat with him about it this morning after an employee blew it off as compression and he said he'd look at it personally for me. Everyone on my block is dying for someone to figure it out.

Tarry, where is your shop?

 

[BusaDave9]

I would bypass the Ignition and hook a wire directly to the coil from the positive side of the battery.......of course if it starts the only way to kill it would be via taking the wire off and or hold the brakes on and kill it with the clutch.

That eliminated the ignition switch and some wiring.
We're still sure you are getting spark AND fuel? Tested each spark plug wire with a spark tester? Verified that gas squirts into the carb when you press the gas pedal down?
It you are getting spark and fuel, those are the most important things. If it's anything else it would have to be really bad. In other words if it's timing it would have to be FAR off. not just a few degrees. Double check what Old Dog and Tarry were saying to see if the distributor is way off.

Valve timing could be way off. You were saying the compression was very low. It is very possible that the timing chain and cogs are so worn that the chain jumped teeth. That would make the valves open far from the correct time. That would cause the compression to be very low on all cylinders.

 

[tarry99]

Olddog,
I have checked it and its right on the nose. Four different mechanics, one being an electrician, have worked on this Jeep. The one guy that did get it going had it for two days and put a new fuel pump and distributor in it and did not charge me because he felt bad that it didn't solve the problem when he thought it would. He didn't even charge me for the parts. His shop is next door to my office, he has offered any tool in his shop for me to use. He has had several other friends that are mechanics come by and look at it. I can't count how many times he, or someone else, has redone the timing on it. Believe me, I want to be able to say that the guys that have looked at it are hacks. It is now at the electricians, which is on the other side of my office building, and I had a chat with him about it this morning after an employee blew it off as compression and he said he'd look at it personally for me. Everyone on my block is dying for someone to figure it out.

Tarry, where is your shop?

thistle,

In NorCal..............Again, Motors are very basic....... when Professionals check a motor we systematically eliminate things: like correct timing.........
The method I mentioned is the quickest and easiest way to get the motor at TDC. Once there if the timing marks at the vibration dampner hub do not line up with the front cover timing marks then there is a good chance the internal timing is off and most likely the timing chain has either broken or jumped a tooth, if the timing marks are close then you pull the cap and verify that the rotor is in the correct position to fire #1 on the cap , if its off you should rotate the distributor to the correct position which sometimes if it's way off might mean the distributor has to come out and be repositioned. While doing so I also like to have the valve cover off to watch the opening and closing of the Intake and exhaust valves. All basic engine tech 101.
If I like what I see...........I verify the cap is correctly wired in the firing order. I would also check your individual spark plug wires with an Ohm meter and make sure there are no dead wires.....also check voltage across the coil....... If I suspect primary wires to the coil I just hook a jumper up and go direct to the battery ............but make sure you take the original wire off from your Ignition switch..........again all basic engine tech 101.

And as far as fuel .......as long as it's not just falling out of the Carb and flooding the motor or fouling the plugs and the choke is open it should start.

This again is just a process of elimination ..........once I have verified any of the above I do not need to go back again and its on to check a new area.

Now not to say that some burnt valves or low compression or a host of other things that could be worn out will not also affect the performance of your motor but any of these together will not stop it from running.

Fuel , Air , Timing & Ignition...........pretty straight forward!

 

[BrockGrimes]

I drove one to the insurance company one afternoon shut it off paid my insurance and hopped back in and it wouldn't start. Turns out it jumped time when it I shut it off. Replaced the timing chain, retimed and was good to go.

Try this yourself:
How to find TDC & install a distributor - JeepForum.com

Also if you pull a plug and leave it hooked to the wire you can lay it on the block and see if it'll spark no tester needed.

Silly question but when you mash the gas is the carb actually opening?

Had a buddy move the throttle at the carb and saw fuel spray but it wouldn't start while he was in it turned out the throttle cable wasn't actually opening the carb.

 

[BrockGrimes]

I believe a AMC 304 is set the timing at 5 deg BTDC.

An old trick I use is Pull a plug and rotate the motor around to TDC as indicated on the scale.
Then take a long piece of rubber hose and stick it in the hole you shouldn't go in far before contacting a piston, use a long piece as not to loose it in the cylinder.
You can also stick a 1/4 piece of rubber hole in the hole and have a friend hand crank the motor over with a wrench and you'll feel it blow or suck air as you go toward TDC.
When you hit that dead spot where it neither sucks or blows that's TDC or it's in the bottom, here's where a thin LOOOOng piece of hose comes in handy seeing where the piston actually is.

Can someone post up a pic of the dist. when at TDC I don't happen to have one handy.

 

[thistle3585]

Well, the saga continues. Just got it back from the electrician and he says the electrical is fine throughout. The only discrepancy is that he says he's getting 25 pounds on the compression check while the other mechanic and myself are getting 100. Even with low compression would it start but run like ?

 

[BusaDave9]

Could it be that one cylinder has 25 lbs of compression and another has 100?
Sounds like a rebuild

 

[thistle3585]

BusaDave,
I got the Jeep back from the "electrician" today. I did a compression check and everything came out around 100 with #8 being a bit lower at 88. Shot a bit of oil in and it went up to 120. Starting going through a check list of electrical items that was posted by someone else but it started raining before I got too far. I did find a bare positive wire and a badly frayed wire coming off the alternator so I replaced those. It wants to start but just doesn't take off. One of my wife's coworkers husband was a mechanic for Jeep. He said he'd love to come look at it and help me out, so we're going to see if a fresh perspective might have an opinion. We all agree that it acts as if it is losing spark after cranking, but I am getting a positive read on the ignition coil with the key in the run position. I wonder aloud if a bad alternator may be the issue. Just grasping for anything at this point. Will keep you posted.