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Compression check good, now it won't start.

320 Views 14 Replies 5 Participants Last post by  jcm3
1983 D150 slant 6.

Good news, compression check 120 to 130 psi cold. Should the motor be warm?

Bad news now it won't start. Have fire and gas. Spark plug wires are on in the right order. I'm tired and going to bed. Will look at it in the morning. Could the spark plug wires loosened when taking them off? I pulled one plug to check for fire.
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we talkin the 83 or the 87
First line of the post. 1983 D150 slant 6.
right over my head , you pull 1 plug out at a time right
Pulled all the plugs. Thought that was how it was done. I'll go do one at a time.

Was using a remote start switch thinking the coil wouldn't be getting power. Now I'm wondering if the remote switch across the starter could have supplied power to the coil. Would the ignition running ungrounded cause problems?
Couple of the plugs.
Hand Finger Thumb Nail Gas
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Checked timing, it is 20 degrees while cranking over. That doesn't seem right but I don't know what it should be unless it is running. Removed vacuum advance and it checked the same. Distributor clamp is tight and don't think it moved.

Found a loose positive wire on the coil. In fact it popped off when I was checking the spark plug wires. Soldered and shrink wrapped both coil connections. Bypassed the ballast resistor and getting 11.5 volts to the coil. Kind of low but I had cranked the engine over a couple of times and was only getting 12.5 at the battery.

Tried squinting a little gas in the carb, still won't try to start.

Wondering if the timing jumped while I was checking compression. 20 degrees seems odd for starting condition.

I'm thinking of checking each spark plug wire with the timing light. Don't think the light will work unless the spark plug wires are hooked to the plugs and grounded. Easy way to check that all plugs are firing?

It was running well before the compression check.

Going to leave it sit and drink some beer. Ironic that before the compression check it had to be moved to get the mower out. I just made room to park it further back in the shop so I can get the mower out without moving the truck. Lucky me.
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Update #2 It started.

I checked the cap and rotor and found the rotor spring that contacts the center of the cap was bent. Don't think it was making contact. Looks like it was spinning around the boss that holds the center contact in the cap. Pictures below.

It didn't start after bending the rotor spring down a bit. Was thinking maybe the compression check flooded the engine. So I held the throttle pedal to the floor and turned the engine over. It eventually started and after keeping the rpms up for a bit it would idle. Seems to be idling a little rough now where it wasn't before. Just above idle it sounds good.

I'm going to get new plugs, cap, and rotor tomorrow. Not sure which cap and rotor to get though as they are not stock. Any ideas?

Pictures of cap and rotor.

Wheel Automotive tire Motor vehicle Alloy wheel Steering part
Automotive tire Alloy wheel Finger Vehicle brake Rim
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Yea, that contact does not look right. Surprised it did not scratch up the inside of the cap.

That looks like a stock cap and rotor to me. I always get the ones with brass terminals.
The end of the spring contact is rounded so it wouldn't dig in but the cap does show rub marks around the center boss.

I'll take the cap and rotor in with me to the parts store.
Lol, yes, that rotor is pooched! Weird how that ended up like that. 🤔
It happens when the cap is not put on straight down, but is kinda slid from one side. Of course the rotor has to be facing away from the side the cap was slid over from. I have seen it a few times on small blocks, where it is harder to reach the dizzy. I never played with six plug engines enough to see it happen on them.
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He could actually bend that back into shape and run it.
I did bend it back. Still ordered new parts. Will be here this afternoon.
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If it doesn't start with the new parts, couldn't hurt to pull the number one, do the finger test and verify that the timing is close enough to start.
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