73 Bronco 302. Kicks over, won't run

[RussianGeo]

All,
Need your help. I've been a browser of this forum for a long time, but now am in a position to post...

I have a 1973 Bronco 302. Engine 'went through' 8 years ago during the restoration, and in the past few years I've replace the ignition system e.g. Summit electronic distributor, Blaster 2 coil, MSD GAL-2 ignition box and MSD low-res wires. This was back in December, and after getting everything wired and tested, the truck ran fantastic! I was pleased with myself...
Now the truck was sitting for 2.5 months (it's housed in Florida while I live in Texas), and I went to start it, and although it kicked over just fine. It would not stay running.
Diagnosis so far:
1) checked the ignition box for spark - GOOD
2) checked the fuel line - GOOD. It's getting fuel. Since the truck sits for a few months at a time, I keep Sta-Bil in it. It's a Holley 600cfm.
3) re-checked all of the ignition box wiring - GOOD
4) Starter is working fine
5) Battery is good (it sits on a trickle charger during the times I can't be near the truck...)
6) Distributor clamp tight, so I don't think it rotated.
7) Ignition switch inside cab is good. I had replaced that last year
8) Steering column kill switch is predictable (need to make sure it's in the right place before battery gets juice. This will be another project some day to replace the guts of the column.

Now I have to say right before I put it up in December, since I was so happy it was running so well, I was getting on it a bit to "burn the carbon out". Now I'm wondering if I slipped a tooth on the timing chain?? I also still haven't pulled the distributor to re-check if on TDC, or if something is fried inside the distributor.

But I'm confused - it ran so well, pulled into the garage, etc. before letting it sit for the few months.

Any ideas??

thanks in advance!

 

[75MIKE]

It won't stay running or doesn't fire at all?

 

[B RON CO]

Hi, I would check for spark at a spark plug. You can get an in line spark tester for $10. If no spark at the spark plug, check for spark at the coil.
I doubt you have a timing chain issue, but if you line up your harmonic balancer mark to TDC, you can verify if the rotor is pointing to the #1 wire on the distributor cap. It should point to #1, or be 180 out. If you are 180 out, you are on the intake stroke, and if you turn the crankshaft one more full turn clockewise, you will be pointing at #1 on the cap. Post what you find. Good luck

 

[spap]

I agree spark at the plug. You can pull a plug and lay it on the exhaust manifold to check for spark as long as the plug is grounded
If you put fuel in the carb directly does it kick over , if you push down on the throttle linkage on the carb can you hear fuel squirting, when was the last time you replaced the fuel filter

 

[knack]

Maybe some creature made a nest in the air intake when the truck was sitting? No air = no run

 

[Hotrodjohn]

Fuel, compression, ignition with correct timing are required to run. If its starting but wont keep running I would think its a fuel issue in carb, assuming fuel pump is getting it up there, like maybe the bowl is not filling up. If the bowl is filling up even somewhat you should be able to see fuel spraying from the center squirters inside the venturis when you pump the throttle. You could put timing light on number one cylinder and crank it over to see if and where its firing as far as timing or just check the rotor position like Bronco says to verify timing but if it ran when you parked it I wouldn't expect your chain broke or jumped.

 

[RussianGeo]

All - I really appreciate the comments, I will continue diagnosing.

75MIKE: your question, it fires everytime I turn it over, but will not stay running - hence my thought on the timing.

knack - I yanked the air filter, everything is clear.

B RON CO, spap - yep, I'll pick up a spark plug tester, good call.

Hotrodjohn - I'm getting fuel in the clear fuel line filter when I crank the engine e.g. it fills up, however I haven't grabbed an assistant yet to confirm I'm getting spray in the carb.

 

[B RON CO]

Hi, so when the engine is cold, don't touch anything, but remove the air filter. Now just like you are going to start it, floor the gas pedal and make sure the choke is closed.
Now when you crank it you say it tries to start but won't keep running. So maybe you lose spark when the key is on the run position, but you have spark in the start position. Or you aren't getting enough fuel because of a carb issue, which maybe as simple as a choke adjustment.
If the choke does not stay closed, but just flops around, you could try to tighten the choke spring on the passenger side (all the carb co. have it on their web). And you can look for the accelerator pump squirt by (engine off) holding the choke open and giving it gas and you should see 2 healthy squirts down the center of the carb. Don't pump it a lot or you will flood the engine.
Check that and post back. Good luck

 

[RussianGeo]

I'm back, finally made my way to the truck and have been messing with it the past day or so. Unfortunately, I'm still having issues. Very frustrating! But I'm determined to figure this out, hopefully with everyone's help...
Status report, per suggestions above:
- Picked up a spark plug tester, spark is good.
- Did the carb squirt test, this was confirmed too. Getting healthy squirts of fuel.
- Did the TDC test e.g. first time I pulled the dist cap I was 180 out, rotated the crank with my 7/8 socket, and now on #1 cylinder
- also with my hesitant assistant (wife), she cranked and I verified with the timing light I'm at 8 degrees BTC. This is perhaps not optimal, but it should start at 8?
- Tested the MSD GAL-2 ignition box (white wire test), but may do this again. Alternatively I'm now thinking of taking the box out of the picture and go back to the summit Ready to Run distributor / Blaster 2 coil to see if I can get it running.

Suggestions welcome! The truck continues to fire in start mode, but does not stay running.

 

[bronkenn]

I would check the ignition wire for 12 volts when the key is in the run position. Sounds like you got 12 volts in start position, but the run position doesn't. I have seen this happen a couple times. Once was mine. Ken

 

[Rustytruck]

If you have a tachometer attached I would disconnect it until you get this running properly. It sounds like above your not getting power to the ignition system in the run position, only in the start position. Check for voltage at the coil with the key on not start. Do not leave the key on for more than a few seconds to check for voltage. Ford used a resistance wire to the coil from the ignition switch. Some aftermarket systems use a ceramic resistor if this burns out you get a no run condition.

 

[RussianGeo]

Everyone - I really appreciate the help with this. Problem finally solved, and I'm kinda embarrassed to report this.

Should have followed the KISS principle on this one...

Turns out it was a bad ground on my RTR distributor!

After uninstalling latest ignition box to troubleshoot where the problem may have started, I re-checked all wires and connections once again. Also a few months ago I had installed a Ron Francis ground box, but in the cab - so the ground for the distributor went to what I thought was a solid location in the engine bay. Turns out it wasn't.

Once I went through each wire, I found the culprit. The truck is back to running fantastic.

Not a complete loss though, my troubleshooting skills have improved for sure - and I hope in the future I'm able to return the favor!

Now to have some fun and burn some fuel.

 

[svastano]

Good to hear. Normally it is the stupid simple things that trip you up.