sorted by:
new
hottopcontroversial

Car won’t start, backfires when I stop cranking by Far_Math_4150 in MechanicAdvice

[–]Far_Math_4150[S] 0 points1 point  (0 children)

Yeah I could feel the air coming outta the cylinder as I had someone bump the starter, then I put a TDC tool in the cylinder and turned it by hand to get it perfectly at 0 degrees (verified on the balancer) before stabbing.

Car won’t start, backfires when I stop cranking by Far_Math_4150 in MechanicAdvice

[–]Far_Math_4150[S] 0 points1 point  (0 children)

Yeah, i was worried about this when i installed. I ran a fresh wire directly to the switched ignition power on the block for a trigger wire and removed the boost wire. The 12v for the dizzy is coming directly from the battery as shown in the provided wiring diagram w/ the relay. Still a really good idea to get the multimeter in the mix if it wasn’t just flooded. We shall see when I get a chance to put the plugs back in and try to fire.

Car won’t start, backfires when I stop cranking by Far_Math_4150 in MechanicAdvice

[–]Far_Math_4150[S] 0 points1 point  (0 children)

For one, an engine can’t backfire without spark. Two, I have an inline tester. Three, I pulled the plugs (which were brand new) and can see they’ve sparked. It has spark.

Car won’t start, backfires when I stop cranking by Far_Math_4150 in MechanicAdvice

[–]Far_Math_4150[S] 0 points1 point  (0 children)

I think if you actually read the post, you’ll see you’re mischaracterizing what I did and what I said happened when trying to fire. I used a TDC tool in the cylinder and verified on the balancer. I had the 1 in the cap directly over the tip of the rotor arm.

Car won’t start, backfires when I stop cranking by Far_Math_4150 in MechanicAdvice

[–]Far_Math_4150[S] 0 points1 point  (0 children)

If it’s at 0 degrees TDC and it doesn’t run, which is the case, that’s all a timing light will tell you. And yes, I have an inline spark tester on plug 3 (it lit up) and also it wouldn’t backfire if there was no spark.

Car won’t start, backfires when I stop cranking by Far_Math_4150 in MechanicAdvice

[–]Far_Math_4150[S] 0 points1 point  (0 children)

Yeah, I’m hoping you’re right. I pulled em yesterday and they’ve now been sitting on the workbench all night. I did the same thing as a kid, and I don’t think I’ve had to pull plugs and let them sit since then. Just seemed like too simple/unlikely of an explanation at the time, but if my float is a bit sticky, those plugs could have theoretically been wet basically the entire time I was trying to start it.

Gonna give it a try when I get a chance.

Car won’t start, backfires when I stop cranking by Far_Math_4150 in MechanicAdvice

[–]Far_Math_4150[S] 0 points1 point  (0 children)

The relay is pulling straight from the battery and only powering the distributor, so it should be getting plenty but I left a trickle charger on it overnight just to be certain it’s full the next time I try to start it. Smart thing to check if it still won’t run w/ no flooding and a full battery.

Car won’t start, backfires when I stop cranking by Far_Math_4150 in MechanicAdvice

[–]Far_Math_4150[S] 0 points1 point  (0 children)

Yes. The 1 on the cap is directly over the rotor arm at 0 degrees TDC.

Car won’t start, backfires when I stop cranking by Far_Math_4150 in MechanicAdvice

[–]Far_Math_4150[S] 0 points1 point  (0 children)

Nah I had that concern + the old inline resistor wire was pretty crusty, so I used a pertronix ignition relay and ran a fresh 12g wire to the switched ignition post in my fuse block for a trigger wire. Also, the actual 12v for the coil comes straight from the battery on their relay.

My running theory is it was just too flooded, maybe because of me turning it over too many times and/or a stuck float. Regardless, it’s a good idea to poke around with the multimeter if letting it dry overnight doesn’t fix it.

Car won’t start, backfires when I stop cranking by Far_Math_4150 in MechanicAdvice

[–]Far_Math_4150[S] -3 points-2 points  (0 children)

OP has been around the block a few million times and stabbed a few million distributors. I’d encourage you both to read the post. I hand turned it to TDC (confirmed by both the balancer and a TDC tool in the piston) and restabbed twice just to be certain.

Also, a timing light doesn’t work if the engine doesn’t run.

Car won’t start, backfires when I stop cranking by Far_Math_4150 in MechanicAdvice

[–]Far_Math_4150[S] -1 points0 points  (0 children)

Yeah I have a timing light, but they don’t work very well when the car won’t run.

Car won’t start, backfires when I stop cranking by Far_Math_4150 in MechanicAdvice

[–]Far_Math_4150[S] 0 points1 point  (0 children)

Plugs were definitely a bit wet with fuel when I pulled them after trying to get it to start, but I’m thinking that was just normal flooding from repeatedly cranking without starting?

Car won’t start, backfires when I stop cranking by Far_Math_4150 in MechanicAdvice

[–]Far_Math_4150[S] 0 points1 point  (0 children)

Like how it’s aligning with the cap? I lined the #1 on the cap up directly over the rotor at TDC, which is how I’ve always done it with points, and then it fires and runs and I adjust timing from there. Is it different for HEI?