86 Won't Crank- Need Suggestions
Thread Starter
Racer
Joined: Sep 2008
Posts: 403
Likes: 7
From: Space Coast Florida
86 Won't Crank- Need Suggestions
Hello All,
Replaced intake manifold and buttoned everything up. Got a few cranks to try and get started and now the starter won't crank the engine. Replaced battery. Replaced solenoid, bench tested starter motor and flywheel spins and engages fine. You can hear it try to engage when you turn key but then nothing. I can also spin the motor with a wrench.
Edit: oh no... Doesn't look like it's hand turning clockwise but will counterclockwise?
Hard stop in each direction at cylinder 8 and 180 degrees.
What can I even check?
Replaced intake manifold and buttoned everything up. Got a few cranks to try and get started and now the starter won't crank the engine. Replaced battery. Replaced solenoid, bench tested starter motor and flywheel spins and engages fine. You can hear it try to engage when you turn key but then nothing. I can also spin the motor with a wrench.
Edit: oh no... Doesn't look like it's hand turning clockwise but will counterclockwise?
Hard stop in each direction at cylinder 8 and 180 degrees.
What can I even check?
Last edited by 21boy; Mar 23, 2025 at 02:58 PM.
Melting Slicks
Joined: Oct 2003
Posts: 2,189
Likes: 830
From: Chapel Hill NC
2025 c3 ('68-'73) of the Year Finalist - Unmodified
2025 C4 of the Year Finalist - Unmodified
2025 C8 Stingray of the Year Finalist - Unmodified
How are the battery cables and grounds?
Drifting
Joined: Jan 2021
Posts: 1,313
Likes: 384
From: Northern California
Don't freak just yet. I'm thinking that at some point in your hand turning, you are reaching the compression stroke on a cylinder and both valves are closed. It would be hard to rotate at that point.
If you are concerned that you have hydro-locked a cylinder, remove all the spark plugs and then try to rotate by hand. It should rotate without restriction then, and if you have fuel or other liquid such as coolant in a cylinder it will likely expel some thru the spark plug hole. Check and see what you find.
On your starter, the battery needs to be strong. I would suggest removing the battery and taking it to a parts store for testing.
If you are concerned that you have hydro-locked a cylinder, remove all the spark plugs and then try to rotate by hand. It should rotate without restriction then, and if you have fuel or other liquid such as coolant in a cylinder it will likely expel some thru the spark plug hole. Check and see what you find.
On your starter, the battery needs to be strong. I would suggest removing the battery and taking it to a parts store for testing.
Melting Slicks
Joined: Oct 2003
Posts: 2,189
Likes: 830
From: Chapel Hill NC
2025 c3 ('68-'73) of the Year Finalist - Unmodified
2025 C4 of the Year Finalist - Unmodified
2025 C8 Stingray of the Year Finalist - Unmodified
As already suggested, remove spark plugs and then rotate clockwise. I cant rotate an engine manually with the plugs in but Im old and weak. Im also under the impression you can break the front bolt with manual rotation with the plugs installed.
Thread Starter
Racer
Joined: Sep 2008
Posts: 403
Likes: 7
From: Space Coast Florida
So update, plugs removed and it's moving fine until 2 points. If you're standing in front of the car:
before cylinder 1 TDC compression stroke and 180 degrees before on the distributor, if you're looking at the cap, it's between 6 and 3 almost on the screw and 1 and 8, again on the screw. Almost like a valve is stuck and hitting a piston???
I didn't see anything come out of the cylinders but strong smell of gas.
Almost like a valve is stuck and hitting a piston??? Should I remove valve covers and see if they're all moving?
before cylinder 1 TDC compression stroke and 180 degrees before on the distributor, if you're looking at the cap, it's between 6 and 3 almost on the screw and 1 and 8, again on the screw. Almost like a valve is stuck and hitting a piston???
I didn't see anything come out of the cylinders but strong smell of gas.
Almost like a valve is stuck and hitting a piston??? Should I remove valve covers and see if they're all moving?
Last edited by 21boy; Mar 24, 2025 at 11:47 AM.
Drifting
Joined: Jan 2021
Posts: 1,313
Likes: 384
From: Northern California
Something else is going on here that needs more thought, something not included in your original post.
Tell more about why you replaced the intake manifold. Was it leaking coolant into the motor? You just removed the stock intake and resealed it? You removed the distributor, TPI plenum, injectors, fuel lines, hoses, etc, and it all went back fine? The distributor was marked and put back exactly in the same timing position?
There's nothing in that job that would have caused the issue you describe, unless there is a physical obstruction in the distributor rotor turning, or something jammed in the motor such as debris that fell in while the intake was off, something fell into a port in the head, etc... Intake valves don't fall into the piston unless the retainer has come off the top of the valve or the valve stem has broken, etc, not likely.....
What else has happened that you can share, before and after this job was done? What other issues came up during the job, or what other symptoms besides what you described in the "few cranks" to get it started?
Tell more about why you replaced the intake manifold. Was it leaking coolant into the motor? You just removed the stock intake and resealed it? You removed the distributor, TPI plenum, injectors, fuel lines, hoses, etc, and it all went back fine? The distributor was marked and put back exactly in the same timing position?
There's nothing in that job that would have caused the issue you describe, unless there is a physical obstruction in the distributor rotor turning, or something jammed in the motor such as debris that fell in while the intake was off, something fell into a port in the head, etc... Intake valves don't fall into the piston unless the retainer has come off the top of the valve or the valve stem has broken, etc, not likely.....
What else has happened that you can share, before and after this job was done? What other issues came up during the job, or what other symptoms besides what you described in the "few cranks" to get it started?
Thread Starter
Racer
Joined: Sep 2008
Posts: 403
Likes: 7
From: Space Coast Florida
Removed old manifold, replaced with super Ram. Fuel rail was in place but I removed enough to fit it comfortably.
Two things that I can think of,
1. Removed distributor to fit intake. I did however mark TDC of piston 1 and rotate oil pump rod so that I can fit it back into a position so that it fit with the bigger intake.
2. Cleaned up a lot of the old sealant with a Dremel sander head. Im worried on of those fell down my cylinder 6 intake when I had the runnes off. I saw it happen but it was so fast that Im not 100% sure. I vacuum and scoped the intake for #6 with a snake camera and didn't see anything so I thought it had gone somewhere else. I'm now kicking myself for not tearing the I take manifold off again.
But yea, I put it all back together cranked it a few times, had distributor close enough to cause it to turn over. Heard it miss and stop at 10 seconds of running. Then nothing.
Edit: im sorry for not including that originally but it's been a blur and I'm trying to think of anything that could have happened. Again, kicking myself here.
Two things that I can think of,
1. Removed distributor to fit intake. I did however mark TDC of piston 1 and rotate oil pump rod so that I can fit it back into a position so that it fit with the bigger intake.
2. Cleaned up a lot of the old sealant with a Dremel sander head. Im worried on of those fell down my cylinder 6 intake when I had the runnes off. I saw it happen but it was so fast that Im not 100% sure. I vacuum and scoped the intake for #6 with a snake camera and didn't see anything so I thought it had gone somewhere else. I'm now kicking myself for not tearing the I take manifold off again.
But yea, I put it all back together cranked it a few times, had distributor close enough to cause it to turn over. Heard it miss and stop at 10 seconds of running. Then nothing.
Edit: im sorry for not including that originally but it's been a blur and I'm trying to think of anything that could have happened. Again, kicking myself here.
Last edited by 21boy; Mar 25, 2025 at 08:07 AM.
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Melting Slicks
Joined: Feb 2003
Posts: 2,677
Likes: 812
From: Saskatoon Sask.
Removed old manifold, replaced with super Ram. Fuel rail was in place but I removed enough to fit it comfortably.
Two things that I can think of,
1. Removed distributor to fit intake. I did however mark TDC of piston 1 and rotate oil pump rod so that I can fit it back into a position so that it fit with the bigger intake.
2. Cleaned up a lot of the old sealant with a Dremel sander head. Im worried on of those fell down my cylinder 6 intake when I had the runnes off. I saw it happen but it was so fast that Im not 100% sure. I vacuum and scoped the intake for #6 with a snake camera and didn't see anything so I thought it had gone somewhere else. I'm now kicking myself for not tearing the I take manifold off again.
But yea, I put it all back together cranked it a few times, had distributor close enough to cause it to turn over. Heard it miss and stop at 10 seconds of running. Then nothing.
Edit: im sorry for not including that originally but it's been a blur and I'm trying to think of anything that could have happened. Again, kicking myself here.
Two things that I can think of,
1. Removed distributor to fit intake. I did however mark TDC of piston 1 and rotate oil pump rod so that I can fit it back into a position so that it fit with the bigger intake.
2. Cleaned up a lot of the old sealant with a Dremel sander head. Im worried on of those fell down my cylinder 6 intake when I had the runnes off. I saw it happen but it was so fast that Im not 100% sure. I vacuum and scoped the intake for #6 with a snake camera and didn't see anything so I thought it had gone somewhere else. I'm now kicking myself for not tearing the I take manifold off again.
But yea, I put it all back together cranked it a few times, had distributor close enough to cause it to turn over. Heard it miss and stop at 10 seconds of running. Then nothing.
Edit: im sorry for not including that originally but it's been a blur and I'm trying to think of anything that could have happened. Again, kicking myself here.
Thread Starter
Racer
Joined: Sep 2008
Posts: 403
Likes: 7
From: Space Coast Florida
Some debris ontop of cylinder 6
Different angle
Vacuumed the spark plug hole and it got the larger stuff. Piston still doesn't want to travel to its furthest point.
Valves appear to be fine, from above and below. I looked at them in the scope as well.
Thread Starter
Racer
Joined: Sep 2008
Posts: 403
Likes: 7
From: Space Coast Florida
Update:
Took to shop. They jumped it and it turned over but said have no compression on cylinder #2 and low on #6.
I'm kinda floored but I guess things happen in life. They're going to bore scope #2 and see if the block is salvagable.
Took to shop. They jumped it and it turned over but said have no compression on cylinder #2 and low on #6.
I'm kinda floored but I guess things happen in life. They're going to bore scope #2 and see if the block is salvagable.