350 - Cranking, won't fire

[theblindchicken]

Hey guys,

Trying to get my truck running today.

New build, but I can't get it to fire. It's cranking easily, but just won't fire. Has a small pop with a bit of smoke, but I can't tell if it's coming from the carb or from the exhaust since it's headers to muffler to tip right about the transfer case.

Build:

SBC 350 .030" over
Hypereutectic Pistons
76cc Smogger heads
HEI Distributor
Mild Comp Cam
Stock 1.5:1 rockers
Mechanical Fuel Pump
Quadrajet 4-bbl Carb.

All help is appreciated.

 

[theblindchicken]

Verified spark with a timing light on cyl 1.

I can smell fuel in the carb, but I don't see any fuel being sprayed when pumping the throttle cable.

Getting a pop out of the exhaust now after further cranking.

 

[theblindchicken]

Still don't see any fuel being sprayed, but there is fuel in the intake manifold when looking down through the secondaries.

Smoke in the carb and more pops from the exhaust now.

Possible that the distributor is 180 out?

 

[Blue Ox]

Certainly a possibility. Also check firing order.

 

[Rickf]

If your firing order and timing is correct, make sure you are getting 12 volts to the HEI while cranking.

 

[Rusty Nail]

1-8-4-3-6-5-7-2

But i expect there would be more popping and there is easy cranking.

Are you telling us that when you work the throttle, the carb don't squirt gas ON DEMAND?

 

[Rusty Nail]

Plus there's no pix.
Wtf?

 

[bucket]

Still don't see any fuel being sprayed, but there is fuel in the intake manifold when looking down through the secondaries.

Smoke in the carb and more pops from the exhaust now.

Possible that the distributor is 180 out?

Sounds like 180 out.

 

[1987 GMC Jimmy]

Are you telling us that when you work the throttle, the carb don't squirt gas ON DEMAND?

This could be a problem...

Also, it sounds more like timing to me. The distributor might be a tooth off or inverted 180*.

 

[theblindchicken]

Thanks guys. I'll continue on it in the morning tomorrow or on Saturday.

Certainly a possibility. Also check firing order.

I marked the distributor with a paint marker when I initially made the plugs as well as have a retaining plate to help ensure I don't mess up the firing order in the future.

If your firing order and timing is correct, make sure you are getting 12 volts to the HEI while cranking.

I'll double check the voltage at the HEI connector. Brand new battery (November/December '18 ish)

1-8-4-3-6-5-7-2

But i expect there would be more popping and there is easy cranking.

Are you telling us that when you work the throttle, the carb don't squirt gas ON DEMAND?

The throttle cable is messed up in that the clip broke that's supposed to hold it in place inside the metal bracket off the carburetor. I need to get a new one, I don't see any fuel squirting when operating the throttle from closed to wide open. However, there is fuel sitting inside the intake manifold when looking down through the secondaries. Maybe the jets got a bit clogged up sitting around since it last ran?

Plus there's no pix.
Wtf?

I'll grab some pictures tomorrow or Saturday.

Sounds like 180 out.

I'll make sure to double check that.


Appreciate all the help so far guys.

 

[theblindchicken]

This could be a problem...

Also, it sounds more like timing to me. The distributor might be a tooth off or inverted 180*.

I set it so I saw the intake valve close (around 6-8 o' clock), then continued to rotate it clockwise until it reached the 0* for the timing mark. Could have missed a tooth on the cam though. It was pointed pretty close to cyl 1. maybe between 1&3.

Thanks for the help.

 

[bucket]

I set it so I saw the intake valve close (around 6-8 o' clock), then continued to rotate it clockwise until it reached the 0* for the timing mark. Could have missed a tooth on the cam though. It was pointed pretty close to cyl 1. maybe between 1&3.

Thanks for the help.

Both valves need to be closed to make it true tdc.

"A tooth off" doesn't really exist with a Chevy V8. You can set it in there wherever you want, so long as there's room to rotate the housing where it needs to be.

 

[Rusty Nail]

But there's got to be gas though or it won't run.

I'm just sayin..

Dude. When you work the throttle from closed (idle) to WOT, there is two humungous sprays of gas (one in each bore) what make a big assed WHOOSHing sound...it's pretty hard to miss.

 

[bucket]

But there's got to be gas though or it won't run.

I'm just sayin..

Dude. When you work the throttle from closed (idle) to WOT, there is two humungous sprays of gas (one in each bore) what make a big assed WHOOSHing sound...it's pretty hard to miss.

You must have better vision than me. Several times I've thought there wasn't fuel squirting. I've had to climb up and basically lay on the engine with my face on the carb to see and hear the pump shot.

 

[Rusty Nail]

Maybe ya'll got weak assed accelerator pumps!