TheSamba.com :: View topic

Wed Jun 25, 2025 6:22 pm

the firing order is 1 - 4 - 3 - 2. On a type 4 engine, it is incredibly easy to get the wires on 1 and 2 or even 3 and 4 reversed. It is also easy to accidentally go the wrong direction putting the wires on unless some one is doing it daily. If someone goes the wrong direction and accidentally swaps 3 and 4, it will fire properly on 3 and 4 but not 1 and 2. Likewise, if someone gets the order right, but swaps 1 and 2 accidentally when they dive down by the tower and come back up, 1 and 2 won't fire. I would start with the plug wires and make sure 1000% they are on correctly before I started playing, "what is wrong with the carb." It may be a carb or vacuum leak, but check the wires. On my 1977 I can't even see the number 1 and 2 wire from behind the bus except at the distributor and the plugs so for me, it is always a challenge to make sure the correct wire is on the correct plug on that side.

Fri Jun 27, 2025 9:22 pm

So did a compression test and it’s had zero compression. Thinking maybe the hydraulic lifters my be bad?

Fri Jun 27, 2025 9:33 pm

Tbrier100 wrote: So did a compression test and it’s had zero compression. Thinking maybe the hydraulic lifters my be bad? even with collapsed lifters you should have some compression in those cylinders. Go back and adjust the valve again.

Fri Jun 27, 2025 9:39 pm

Tbrier100 wrote: So did a compression test and it’s had zero compression. Thinking maybe the hydraulic lifters my be bad?
Check and adjust the valves and if there is not a significant reason visable, do a leak test.

Fri Jun 27, 2025 9:46 pm

I am going to guess that whoever adjusted the valves did not find the point of contact correctly and has the valves set so tight that they are being held open at TDC Compression. If the particular lifter you are setting the preload for is not filled 100% with oil then the point of contact is going to be very subtle and takes a bit of fineness to find. One needs to back the adjusting screw way out and then turn it in slowly using only one's fingers to turn it. Rock the rocker back and forth very gently as you are turning the screw in and feeling for when the rocker just puts the lightest pressure on the pushrod. When the rocker just touches the valve stem and very gently touches the pushrod at the same time that is the point of contact. Now turn the screw in another turns.

Fri Jun 27, 2025 11:01 pm

wagen19 wrote: Tbrier100 wrote: So did a compression test and it’s had zero compression. Thinking maybe the hydraulic lifters my be bad?
Check and adjust the valves and if there is not a significant reason visable, do a leak test.
To find out if it´s an issue of valves, valvetrain, you can remove the all rockers on right side, also remove the spark plugs of cylinder 3 and 4, and turn the engine. NOW the engine MUST have compression on cylinder 1 and 2, if there are no leaks at rings or between cylinders and head. With removed spark plug 1 or 2, you can check each cylinder separatly. In case of doubt, you can check cylinder 3 and 4 the same way.
Out of an old spark plug, I made a tool in perfect length, which allows to connect a normal air pressure hose and bring pressurized air inside the cylinder, when engine is istalled. But there are also ready tools for that to buy.

Sat Jun 28, 2025 4:09 am

Wildthings wrote: I am going to guess that whoever adjusted the valves did not find the point of contact correctly and has the valves set so tight that they are being held open at TDC Compression. If the particular lifter you are setting the preload for is not filled 100% with oil then the point of contact is going to be very subtle and takes a bit of fineness to find. One needs to back the adjusting screw way out and then turn it in slowly using only one's fingers to turn it. Rock the rocker back and forth very gently as you are turning the screw in and feeling for when the rocker just puts the lightest pressure on the pushrod. When the rocker just touches the valve stem and very gently touches the pushrod at the same time that is the point of contact. Now turn the screw in another turns.

I did the valve adjustment initially and I had them all to tight, I re did it yesterday on all cylinders and it ran really nice but still a dead two cylinder, I’ll try again today, I have a leak down tester so I’ll start there. I’ve heard the hydraulic lifters can take a bit to bleed up

Sat Jun 28, 2025 4:29 am

Wildthings wrote: I am going to guess that whoever adjusted the valves did not find the point of contact correctly and has the valves set so tight that they are being held open at TDC Compression. If the particular lifter you are setting the preload for is not filled 100% with oil then the point of contact is going to be very subtle and takes a bit of fineness to find. One needs to back the adjusting screw way out and then turn it in slowly using only one's fingers to turn it. Rock the rocker back and forth very gently as you are turning the screw in and feeling for when the rocker just puts the lightest pressure on the pushrod. When the rocker just touches the valve stem and very gently touches the pushrod at the same time that is the point of contact. Now turn the screw in another turns. if the lifters are bad would that cause zero compression, when I did compression test the needle didn’t move at all

Sat Jun 28, 2025 7:09 am

Tbrier100 wrote: Wildthings wrote: I am going to guess that whoever adjusted the valves did not find the point of contact correctly and has the valves set so tight that they are being held open at TDC Compression. If the particular lifter you are setting the preload for is not filled 100% with oil then the point of contact is going to be very subtle and takes a bit of fineness to find. One needs to back the adjusting screw way out and then turn it in slowly using only one's fingers to turn it. Rock the rocker back and forth very gently as you are turning the screw in and feeling for when the rocker just puts the lightest pressure on the pushrod. When the rocker just touches the valve stem and very gently touches the pushrod at the same time that is the point of contact. Now turn the screw in another turns. if the lifters are bad would that cause zero compression, when I did compression test the needle didn’t move at all

If you fail to find the true point of contact for a soft hydraulic lifter, it's possible to turn the adjusting screws in so far that the valves are held open, which leads to no compression. The problem is not the lifters themselves, but the faulty adjustment technique.

Sat Jun 28, 2025 7:34 am

Wildthings wrote: Tbrier100 wrote: Wildthings wrote: I am going to guess that whoever adjusted the valves did not find the point of contact correctly and has the valves set so tight that they are being held open at TDC Compression. If the particular lifter you are setting the preload for is not filled 100% with oil then the point of contact is going to be very subtle and takes a bit of fineness to find. One needs to back the adjusting screw way out and then turn it in slowly using only one's fingers to turn it. Rock the rocker back and forth very gently as you are turning the screw in and feeling for when the rocker just puts the lightest pressure on the pushrod. When the rocker just touches the valve stem and very gently touches the pushrod at the same time that is the point of contact. Now turn the screw in another turns. if the lifters are bad would that cause zero compression, when I did compression test the needle didn’t move at all

If you fail to find the true point of contact for a soft hydraulic lifter, it's possible to turn the adjusting screws in so far that the valves are held open, which leads to no compression. The problem is not the lifters themselves, but the faulty adjustment technique.

Makes sense ya I have not driven it yet or have had it running to long because I still need to bed in the rings. You think I should do a leak down first, if valves are open re adjust and go drive it to bleed them up?

Sat Jun 28, 2025 7:35 am

Wildthings wrote: Tbrier100 wrote: Wildthings wrote: I am going to guess that whoever adjusted the valves did not find the point of contact correctly and has the valves set so tight that they are being held open at TDC Compression. If the particular lifter you are setting the preload for is not filled 100% with oil then the point of contact is going to be very subtle and takes a bit of fineness to find. One needs to back the adjusting screw way out and then turn it in slowly using only one's fingers to turn it. Rock the rocker back and forth very gently as you are turning the screw in and feeling for when the rocker just puts the lightest pressure on the pushrod. When the rocker just touches the valve stem and very gently touches the pushrod at the same time that is the point of contact. Now turn the screw in another turns. if the lifters are bad would that cause zero compression, when I did compression test the needle didn’t move at all

If you fail to find the true point of contact for a soft hydraulic lifter, it's possible to turn the adjusting screws in so far that the valves are held open, which leads to no compression. The problem is not the lifters themselves, but the faulty adjustment technique. I went to point of contact and then went in 1.5 turns

Sat Jun 28, 2025 7:38 am

rolling the push rod with your thumb and fore finger,while finger turning the adjusting screw,help define the contact point,you should be able to detect resistance to the rolling motion when contact is made.

Sat Jun 28, 2025 7:43 am

lil-jinx wrote: rolling the push rod with your thumb and fore finger,while finger turning the adjusting screw,help define the contact point,you should be able to detect resistance to the rolling motion when contact is made.

That’s a good idea I’ll try that

Sat Jun 28, 2025 10:32 am

Tbrier100 wrote: Wildthings wrote: Tbrier100 wrote: Wildthings wrote: I am going to guess that whoever adjusted the valves did not find the point of contact correctly and has the valves set so tight that they are being held open at TDC Compression. If the particular lifter you are setting the preload for is not filled 100% with oil then the point of contact is going to be very subtle and takes a bit of fineness to find. One needs to back the adjusting screw way out and then turn it in slowly using only one's fingers to turn it. Rock the rocker back and forth very gently as you are turning the screw in and feeling for when the rocker just puts the lightest pressure on the pushrod. When the rocker just touches the valve stem and very gently touches the pushrod at the same time that is the point of contact. Now turn the screw in another turns. if the lifters are bad would that cause zero compression, when I did compression test the needle didn’t move at all

If you fail to find the true point of contact for a soft hydraulic lifter, it's possible to turn the adjusting screws in so far that the valves are held open, which leads to no compression. The problem is not the lifters themselves, but the faulty adjustment technique. I went to point of contact and then went in 1.5 turns

My point is that the point of contact can be very subtle and easily missed. Maybe try backing the adjusters on that side off by two turns and see if you get compression.

Sat Jun 28, 2025 10:34 am

Wildthings wrote: Tbrier100 wrote: Wildthings wrote: Tbrier100 wrote: Wildthings wrote: I am going to guess that whoever adjusted the valves did not find the point of contact correctly and has the valves set so tight that they are being held open at TDC Compression. If the particular lifter you are setting the preload for is not filled 100% with oil then the point of contact is going to be very subtle and takes a bit of fineness to find. One needs to back the adjusting screw way out and then turn it in slowly using only one's fingers to turn it. Rock the rocker back and forth very gently as you are turning the screw in and feeling for when the rocker just puts the lightest pressure on the pushrod. When the rocker just touches the valve stem and very gently touches the pushrod at the same time that is the point of contact. Now turn the screw in another turns. if the lifters are bad would that cause zero compression, when I did compression test the needle didn’t move at all

If you fail to find the true point of contact for a soft hydraulic lifter, it's possible to turn the adjusting screws in so far that the valves are held open, which leads to no compression. The problem is not the lifters themselves, but the faulty adjustment technique. I went to point of contact and then went in 1.5 turns

My point is that the point of contact can be very subtle and easily missed. Maybe try backing the adjusters on that side off by two turns and see if you get compression.

I’m going to try this today. I appreciate it thank you

Sat Jun 28, 2025 1:04 pm

Wildthings wrote: Tbrier100 wrote: Wildthings wrote: Tbrier100 wrote: Wildthings wrote: I am going to guess that whoever adjusted the valves did not find the point of contact correctly and has the valves set so tight that they are being held open at TDC Compression. If the particular lifter you are setting the preload for is not filled 100% with oil then the point of contact is going to be very subtle and takes a bit of fineness to find. One needs to back the adjusting screw way out and then turn it in slowly using only one's fingers to turn it. Rock the rocker back and forth very gently as you are turning the screw in and feeling for when the rocker just puts the lightest pressure on the pushrod. When the rocker just touches the valve stem and very gently touches the pushrod at the same time that is the point of contact. Now turn the screw in another turns. if the lifters are bad would that cause zero compression, when I did compression test the needle didn’t move at all

If you fail to find the true point of contact for a soft hydraulic lifter, it's possible to turn the adjusting screws in so far that the valves are held open, which leads to no compression. The problem is not the lifters themselves, but the faulty adjustment technique. I went to point of contact and then went in 1.5 turns

My point is that the point of contact can be very subtle and easily missed. Maybe try backing the adjusters on that side off by two turns and see if you get compression.

It worked, we have compression on all 4 and it runs on all cylinders!!

Sat Jun 28, 2025 2:17 pm

:thumbsup: :thumbsup: :thumbsup: :thumbsup:

Sat Jun 28, 2025 2:18 pm

Wildthings wrote: :thumbsup: :thumbsup: :thumbsup: :thumbsup:

^^^^^^^ this. Awesome

For the record, Mike (Wildthings) is the master at adjusting hydraulic valves.

Sat Jun 28, 2025 9:42 pm

It always amazes me that nobody markets a set of spark plug wires in red green blue yellow for ACVW' which would eliminate misrouting as well as reaffirming our commitment to Developed Engine Ignition systems

Sat Jun 28, 2025 11:12 pm

Abscate wrote: It always amazes me that nobody markets a set of spark plug wires in red green blue yellow for ACVW' which would eliminate misrouting as well as reaffirming our commitment to Developed Engine Ignition systems great idea but too simple. Need a chip in the cap that reads where the wires go and reports out loud, "incorrect wire placement. Move wire between spark plugs until it beeps..." and pray Hal never gets a sense of humor... .