Bronco cranks, but won't start.

[rbwamsley]

I tried to take the bronco for a quick drive last weekend, and I couldn't get it started. It cranks over like crazy (I keep a battery tender on it), but just won't fire. I took at the look at my fuel filter (right next to the distributor) and it had fuel and was clean. I have a Performance Distributors D.U.I. and the B.C. Broncos Quadrajet carb.
At this point I have done zero investigation, but my first step was going to be checking for spark at the plugs with an in-line spark tester. Next, chekck to make sure the carb is squirting gas. Other than that, I'm at a loss...

Any ideas on things to check, where to start looking, or common bronco issues would be greatly appreciated.

Thanks

 

[DirtDonk]

You’re on the right track.
You can check for fuel quickly by pulling the air cleaner off and rocking the throttle back-and-forth to see if you’re getting any fuel squirting in. If you’re not, then it doesn’t matter whether there’s gas in the filter or not. There’s nothing getting into the engine when it’s cranking.
Of course you could also test that theory by dropping a couple of drops of gasoline directly into the carburetor. If it coughs and sputters, then you have spark.
Not necessarily good spark, but spark.

The spark plug tester is great, you can always do that with a timing light as well. If you have a timing light, simply connect it and watch for the pulses as the engine is cranking.
If not, then you’ll have to start by finding out where the power is and isn’t.
Check your power wire to the distributor and go from there.

Another quick test is to turn the key until it just starts to crank. Do not push it any farther.
If it tries to start at that point, then there are a few other things to test.

 

[bronco italiano]

fuel pump type?

 

[rbwamsley]

fuel pump type?

Mechanical

 

[Johnnyb]

Like @DirtDonk said, you can look inside the carburetor and see the accelerator pump actuating and squirting gas down the throat. If the accelerator pump is moving fuel it's at least enough to cause the vehicle to fire and run for a couple of seconds.
I would test spark second. Obviously no spark no fire.
If no spark remove the distributor cap and make sure the rotor is turning while cranking, before moving to other ignition diagnostic or parts replacement.

-JB

 

[rbwamsley]

Thanks to everyone for their responses. I plan to work on it this weekend and will report back.


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[laserfish]

Just had to put ANOTHER fuel pump on. No more cheap ones for me. I sure hope the Edelbrock lasts longer for the price. It would crank all day with the fuel filter holding gas but no gas to the carb. Put on the new fuel pump and started right up. I believe the gas today just eats up the seals if they sit very long at all. Taking off the line to see if the pump causes fuel to flow will tell you. Just be careful as I have had a fire by the carb backfire.

 

[bronco italiano]

Just had to put ANOTHER fuel pump on. No more cheap ones for me. I sure hope the Edelbrock lasts longer for the price. It would crank all day with the fuel filter holding gas but no gas to the carb. Put on the new fuel pump and started right up. I believe the gas today just eats up the seals if they sit very long at all. Taking off the line to see if the pump causes fuel to flow will tell you. Just be careful as I have had a fire by the carb backfire.

Great. Edelbrock and RobbMC make nice fuel pumps.
Regarding the carb fire, I hope your using the stock type cleaner. My buddy had the edelbrock Pro-flo 1002 with the foam element and one carb backfire was all it took to cook his engine bay.

 

[DirtDonk]

Yeah, I’m actually shocked that those are still legal to sell.
I’m not surprised that a company like Edelbrock would continue selling them though, because to discontinue it would almost be a de facto admission that they had a dangerous product for sale. Leading to future lawsuits perhaps.
Same reason Remington(?) didn’t fix a defective trigger and just brought a new model to market years later, while still selling the defective old one. Crazy…

They could just say, “safe for use only on a properly running engine“ and avoid responsibility for backfires causing fires, I suppose.
Hmm, I wonder if they actually say that on the box?

It’s a shame people and companies have to think that way. Lots of pain could’ve been avoided.
And now we have the Sniper II. Should be called the “Sniper Ford”...
But that’s fodder for another discussion…

 

[rbwamsley]

So annoyingly enough, the bronco had no issues starting this weekend. I’m incredibly frustrated at this point.

Guess I’m going to have to look at the issue immediately next time it happens.


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