1980 C10 with a SBC350 quadrajet

[alfredoleffew]

So here my issue, I bought my neighbors truck from them during probate. It’s a 1980 C10 Scottsdale with the BigTen setup. It has a SBC 350 with a quadrajet carb and a TH350 transmission.

I replaced the fuel pump to carb line and internal filter, plugs, wires, cap and rotor. Timing looks good as far the balancers mark and rotor position go.

I can’t get it to start and when I give it gas, it puffs smoke out of the carb. The engines sound also changes when this happens.

What do I do?

 

[Matt69olds]

Start with the basics.

Does it have spark? Is the distributor timed correctly? Does it have compression? When you move the throttle, does fuel spray out the accelerator pump nozzles?

 

[Ricko1966]

Did it start before you started changing things on it? Did you put the plug wires on in the correct order,did you reattach the hot lead on the distributor cap?

 

[fast 99]

Valve or valve timing issue? Disable ignition, crank it, is starter speed even on all cylinders?

 

[alfredoleffew]

Start with the basics.

Does it have spark? Is the distributor timed correctly? Does it have compression? When you move the throttle, does fuel spray out the accelerator pump nozzles?

Yes, it has spark. The timing was verified yesterday but only using rotor position and timing mark on the h-balancer. I didnt think to check for fuel spraying out of the pump nozzles. Ill do that tonight.

 

[alfredoleffew]

Did it start before you started changing things on it? Did you put the plug wires on in the correct order,did you reattach the hot lead on the distributor cap?

Nope, it had many splicings in the wiring that go from the starter to the distro block until I replaced it. I verified the wires and plug order so yes they are in the right order. Yes, all leads are connected.

 

[alfredoleffew]

Valve or valve timing issue? Disable ignition, crank it, is starter speed even on all cylinders?

Possibly. Ill check it out.

 

[Matt69olds]

Yes, it has spark. The timing was verified yesterday but only using rotor position and timing mark on the h-balancer. I didnt think to check for fuel spraying out of the pump nozzles. Ill do that tonight.

The easiest, no nonsense way to verify the distributor and timing are correct is to do as follows:

Remove #1 plug. Crank the engine until you feel compression in the #1 cylinder. Slowly crank the engine in the normal direction of rotation until the timing marks line up with the desired timing figure. Meaning if you want the initial timing set at 10 degrees BTDC, rotate the engine in the normal direction until the marks line up at 10. If you go too far, be sure to turn the engine the other direction far enough to remove all the slack from the timing chain once you start turning it the normal direction again. Once the marks are lined up, don’t move the crank again.

Next, remove the cap. The rotor should be pointing at the number one plug wire. If not, verify the engine is on number one compression stroke, and the plug wires are indexed correctly.

Once that’s done, loosen the distributor hold down bolt. Connect a spark tester to the number one plug wire. Turn on the ignition, BUT DO NOT CRANK THE ENGINE!!! Rotate the distributor back and forth, you should see a spark on the spark tester each time the pickup coil pole pieces pass each other.

If you want to get really technical, you can static time the engine. Remove the rotor, slowly rotate the distributor until the pole pieces line up, then tighten the distributor. Reassemble everything, once the engine is started the ignition timing should be very close to your desired setting.

 

[alfredoleffew]

Gotni

The easiest, no nonsense way to verify the distributor and timing are correct is to do as follows:

Remove #1 plug. Crank the engine until you feel compression in the #1 cylinder. Slowly crank the engine in the normal direction of rotation until the timing marks line up with the desired timing figure. Meaning if you want the initial timing set at 10 degrees BTDC, rotate the engine in the normal direction until the marks line up at 10. If you go too far, be sure to turn the engine the other direction far enough to remove all the slack from the timing chain once you start turning it the normal direction again. Once the marks are lined up, don’t move the crank again.

Next, remove the cap. The rotor should be pointing at the number one plug wire. If not, verify the engine is on number one compression stroke, and the plug wires are indexed correctly.

Once that’s done, loosen the distributor hold down bolt. Connect a spark tester to the number one plug wire. Turn on the ignition, BUT DO NOT CRANK THE ENGINE!!! Rotate the distributor back and forth, you should see a spark on the spark tester each time the pickup coil pole pieces pass each other.

If you want to get really technical, you can static time the engine. Remove the rotor, slowly rotate the distributor until the pole pieces line up, then tighten the distributor. Reassemble everything, once the engine is started the ignition timing should be very close to your desired setting.

Got it. I’ll give it a shot. I move the timing a bit before seeing your reply and it puffed out of the exhaust. I verified the position of the rotor vs the timing mark at #7 since I read that #7 is supposed to be TDC. Once I moved it that next time, it puffed through the carb again.

 

[alfredoleffew]

After checking the timing over and over again, I finally got her to fire up. I set the timing mark to TDC once again and something told me to recheck the rotor (for the 5th time). Behold! 180* out of position. I have no idea how this happened but she fires up.
Now I have to move to the radiator after I dented it and caused a hole. I may as well change the proportioning valve since it’s stuck and without the radiator, it’ll be easy to access.

 

[Ricko1966]

After checking the timing over and over again, I finally got her to fire up. I set the timing mark to TDC once again and something told me to recheck the rotor (for the 5th time). Behold! 180* out of position. I have no idea how this happened but she fires up.
Now I have to move to the radiator after I dented it and caused a hole. I may as well change the proportioning valve since it’s stuck and without the radiator, it’ll be easy to access.

Every other rotation the distributor will be 180* off. That is why you have to confirm you are compression stroke tdc#1 not just tdc#1 . So now you know.