Have spark and fuel, can't get the rebuilt engine to start

Theom

Cadet
Joined
Sep 12, 2019
Messages
20
You've all helped me get fuel and spark, but I can't get the engine to start now. The machine shop installed the internal moving parts, I put everything else on and installed the engine.

Spark: Most recently I verified cylinders 1 and 2 are sparking by setting the spark plug and wire against the block and turning it over. Both have an obvious spark and the plugs look nice and clean. All the spark plugs wires are now and I went through and double checked they're all routed to the correct cylinder.

Fuel: When I pull the fuel line right after the fuel pump off and turn it over, it's obviously squirting gas out of it. When I press down on the accelerator pump on top of the carb it squirts gas into the carb out of both sides under the choke plate. I think this means I've got fuel getting up to the carbs.

Timing:
1) Finding cylinder 1 TDC:
I found top dead center of the compression cycle by attaching a compression tester to cylinder 1 and then manually turning the engine over until the PSI popped up on the pressure gauge. Then I looked through the spark plug hole while turning the engine over manually until I saw the cylinder stop moving upward and marked that spot, then kept moving it until it just started to move down and marked that spot. I used the center between where the cylinder stops moving up and starts moving down as the TDC
2) Align the distributor: I rotated the distributor shaft until it pointed towards about cylinder 1 on the engine because that's where the #1 terminal for the distributor cap was too. Then I rotated the housing until the housing and cap were pretty closely aligned to where the rotor was pointing.
3) Adjustments: After it wouldn't start, I tried using the timing light to set it to 8 degrees before top dead center, but I realized at starting RPM's the mark is in quite a different spot than what it would be at idling RPM's. I then tried rotating it back about 4 degrees at a time for 24 or so degrees and when I'm at about 14 degrees before top dead center at starting speed (not idling speed) it gives the most signs of life but isn't starting.

It seems like I'm getting fuel and spark now, so my assumption is that my timing is off and I just can't figure out how to get everything firing at the right time to get started. I've tried spraying starter fluid into the carbs and pouring 2 oz of gas into the carbs and can't get it to start.

Any help and ideas about what to do now to get it going?
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,315
All the spark plugs wires are now and I went through and double checked they're all routed to the correct cylinder.
Not knowing the engine your working on so:
v6 165432 clockwise
IL4 1342 clockwise
v8 1,8,4,3,6,5,7,2 clockwise
Verify TDC compression again for #1 , where ever rotor is pointing call that #1 cylinder ,install cap and wiring accordingly
 

Scott06

Admiral
Joined
Apr 20, 2014
Messages
6,514
You've all helped me get fuel and spark, but I can't get the engine to start now. The machine shop installed the internal moving parts, I put everything else on and installed the engine.

Spark: Most recently I verified cylinders 1 and 2 are sparking by setting the spark plug and wire against the block and turning it over. Both have an obvious spark and the plugs look nice and clean. All the spark plugs wires are now and I went through and double checked they're all routed to the correct cylinder.

Fuel: When I pull the fuel line right after the fuel pump off and turn it over, it's obviously squirting gas out of it. When I press down on the accelerator pump on top of the carb it squirts gas into the carb out of both sides under the choke plate. I think this means I've got fuel getting up to the carbs.

Timing:
1) Finding cylinder 1 TDC:
I found top dead center of the compression cycle by attaching a compression tester to cylinder 1 and then manually turning the engine over until the PSI popped up on the pressure gauge. Then I looked through the spark plug hole while turning the engine over manually until I saw the cylinder stop moving upward and marked that spot, then kept moving it until it just started to move down and marked that spot. I used the center between where the cylinder stops moving up and starts moving down as the TDC
2) Align the distributor: I rotated the distributor shaft until it pointed towards about cylinder 1 on the engine because that's where the #1 terminal for the distributor cap was too. Then I rotated the housing until the housing and cap were pretty closely aligned to where the rotor was pointing.
3) Adjustments: After it wouldn't start, I tried using the timing light to set it to 8 degrees before top dead center, but I realized at starting RPM's the mark is in quite a different spot than what it would be at idling RPM's. I then tried rotating it back about 4 degrees at a time for 24 or so degrees and when I'm at about 14 degrees before top dead center at starting speed (not idling speed) it gives the most signs of life but isn't starting.

It seems like I'm getting fuel and spark now, so my assumption is that my timing is off and I just can't figure out how to get everything firing at the right time to get started. I've tried spraying starter fluid into the carbs and pouring 2 oz of gas into the carbs and can't get it to start.

Any help and ideas about what to do now to get it going?
Verify the firing order and that you are timing it on tdc of compression stroke vs tdc of exhaust stroke.
loosen distributor and turn it while cranking to see if you can get it to stay running
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,933
Gee, if it won't fire or backfire with ether, the spark is way off. You might pop off the valve cover for #1 cylinder and verify the valves operate properly, and you are installing the distributor so it fires on/near TDC on the compression stroke.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,035
Not an expert here, but is there a mix up with left hand / right hand rotation parts ??
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,276
I've tried spraying starter fluid into the carbs and pouring 2 oz of gas into the carbs and can't get it to start.
There may be spark but it's not enough to ignite the fuel.
Get a spark Gap Tester and connect to coil

Has TB ignition, can also run thru
TBV Troubleshooting.jpg
 

nola mike

Vice Admiral
Joined
Apr 22, 2009
Messages
5,383
I'll throw in here as well, since we don't know the specifics of "won't start" (unless I missed it). Is it catching/back firing/etc? If it wants to start until you let off the key, it's worth checking that you're getting 12v to the coil with ign on. The cranking power circuit is different than the running circuit.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
49,831
There are timing marks on the balancer and timing cover

Easy to get the distributor in 180 degrees out
 
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