5/17 update - FIXED - 77 no start - looking for ideas….

[jeffncs]

Many of you have noticed that I’ve been chasing individual issues to get this 77 running for the first time under my ownership. I’m still chasing a non-running truck and figured I’d put it all together in one place for ideas and suggestions.

Ground up build, never ran under my ownership, getting close though…

Engine / trans
302/5.0HO out of a 94 mustang
C4 with the NSS bypassed to eliminate a variable

Ignition
Stock ignition box, wiring, distributor
I had to make the harness to connect the box-dizzy-body harness. Ive traced the ignition wiring 3x and it looks correct.
Timing set at 12°

Fuel system
Holley 600cfm; Carb is suspect - I cleaned it out last night; ran rich when it was used on another engine. While cleaning the carb, I pulled chunks out of the jet passageI also reset the float heights. Jets are 66s.
Electric fuel pump, relay triggered by a circuit that’s hot when “on“, cold when crank and ACC.
There’s a clear fuel filter just before the carb; fills about 2/3 when fully primed.

Other info
Centech harness

Symptoms
cranks strong, good spark, re-confirmed dizzy is set at TDC, plugs wires and firing order are correct.
I smell some fuel, but not as much as I’d expect for the amount of cranking and hitting the gas pedal.

Some of my ideas…
i may change the fuel pump a circuit to one that stays hot when the ignition is both “ON” and crank.
I may check fuel pump pressure.

 

[Broncobowsher]

If there is fuel in the bowls, the engine has fuel. It will run for a minute or so without a fuel pump just off what is in the bowls. Stop chasing fuel pump issues, that isn't it.
Reused stock distributor on a roller cam engine is a huge red flag. Gear materials are not compatible and WILL self destruct.
You confirmed TDC, but did you confirm TDC on the compression stroke and not the exhaust stroke? There are 2 different TDCs and the wrong one will get you a no start.
For the engine to start at all, fuel in the intake is all you really need. I've seen engines start with the carb removed and fuel splashed down the intake. So while the carb may not be right, it should still start.
Plug wires in the wrong order, it will pop and spit at least. Doesn't sound like you are even getting that.
I'm pretty much calling it the distributor 180 out (wrong TDC) from what I can decipher from your description.

 

[jeffncs]

If there is fuel in the bowls, the engine has fuel. It will run for a minute or so without a fuel pump just off what is in the bowls. Stop chasing fuel pump issues, that isn't it.
Reused stock distributor on a roller cam engine is a huge red flag. Gear materials are not compatible and WILL self destruct.
You confirmed TDC, but did you confirm TDC on the compression stroke and not the exhaust stroke? There are 2 different TDCs and the wrong one will get you a no start.
For the engine to start at all, fuel in the intake is all you really need. I've seen engines start with the carb removed and fuel splashed down the intake. So while the carb may not be right, it should still start.
Plug wires in the wrong order, it will pop and spit at least. Doesn't sound like you are even getting that.
I'm pretty much calling it the distributor 180 out (wrong TDC) from what I can decipher from your description.

Thanks for thoughtful reply.

The dizzy is a stock style and I installed a melonite gear. Sorry about that. Stock style - Duraspark ignition module, stock plug.

I’ll recheck the dizzy. I’ve been known to do the 180° thing!

 

[acropilot]

When you put the front fuel bowl back on the carb you may want to check that the accelerator pump arm is under the linkage correctly.Also work the linkage and watch for fuel coming out of the nozzles in the primaries which works off the accelerator diaphragm and needs no fuel pressure to work as long as there is fuel in the bowl.If no fuel is coming out you will have to replace the diaphragm.Been running those Holley 600's for many years and are about as simple as can be.If you have fuel squirting in then sounds like ignition as previously stated.

 

[jeffncs]

When you put the front fuel bowl back on the carb you may want to check that the accelerator pump arm is under the linkage correctly.Also work the linkage and watch for fuel coming out of the nozzles in the primaries which works off the accelerator diaphragm and needs no fuel pressure to work as long as there is fuel in the bowl.If no fuel is coming out you will have to replace the diaphragm.Been running those Holley 600's for many years and are about as simple as can be.If you have fuel squirting in then sounds like ignition as previously stated.

I’ll double check the accel pump diaphragm. Thanks for the suggestion.

 

[73azbronco]

remove carb, using starter fluid, be careful, does engine start at all using starter fluid down intake? you can do this carb mounted, but sounds like with chunks of old fuel, it needs rebuild.

Send carb to be cleaned, be ready to clean entire fuel line and tank.

 

[jeffncs]

remove carb, using starter fluid, be careful, does engine start at all using starter fluid down intake? you can do this carb mounted, but sounds like with chunks of old fuel, it needs rebuild.

Send carb to be cleaned, be ready to clean entire fuel line and tank.

Thanks. I’ll give the starter fluid a shot just to see if it’ll fire. The carb is spotless inside now. It had 2 aluminum chunks stuck in the fuel ports - see pics of the chunks and the logged chunk prior to removal.

It’s a completely new fuel system otherwise - 0 miles (tank, pump, pre-filter, lines). Carb is the only unknown component.

 

[73azbronco]

how old is the gas in it?

 

[jeffncs]

how old is the gas in it?

Good thought but it’s new gas.

 

[jeffncs]

I dropped a Pertronix and new coil in and ripped all the stock Duraspark stuff out. I don’t know why I didn’t do that to start…guess I was trying to save a few bucks.

Anyway, huge backfire so I’m way out of tune. But, it’s a hige step forward since it shows sign of life!

The backfire sent the dogs shivering into hiding spots and family yelled at me.

 

[73azbronco]

Might be plug wires not on right cylinder, that usually gets you the huge bangs, correct but rough is out of timing or carb messed up.

 

[Broncobowsher]

Went through this again. How did you verify TDC? Timing marks? How mixed and matched is this engine. I ask because Ford used several different timing pointers, and dampers. Mixed and matched and the pointer may not match the marks on the damper. Commonly there are 3 different sets of timing marks, not counting a very rare 4th version you are likely to never see. There is one constant, the keyway on the crank is ALWAYS straight up at #1 TDC. You have to pull the crank bolt and washer to see it, and it can be hard to tell the angle when installed in most engine bays. Damper can stay on, you can see the keyway with just the bolt and washer removed.

 

[jeffncs]

Went through this again. How did you verify TDC? Timing marks? How mixed and matched is this engine. I ask because Ford used several different timing pointers, and dampers. Mixed and matched and the pointer may not match the marks on the damper. Commonly there are 3 different sets of timing marks, not counting a very rare 4th version you are likely to never see. There is one constant, the keyway on the crank is ALWAYS straight up at #1 TDC. You have to pull the crank bolt and washer to see it, and it can be hard to tell the angle when installed in most engine bays. Damper can stay on, you can see the keyway with just the bolt and washer removed.

It’s a 94 5.0 roller engine with the Explorer front dress. The old harmonic balancer had about 160k miles on it so I bought a replacement for the same year explorer at local parts store. The timing chain cover is also explorer and has the stock timing pointer (passenger side due to the lower radiator hose.

I located TDC by watching the #1 intake rocker close after a full cycle. Once it closed, I then shifted eyes to harmonic balancer where I fine-tuned it to point towards 0° timing.

I’m going to throw the TDC whistle in and turn engine over again tonight to see if I’m off. I’ll also double check the wires…. Being a 94, it should have the 1-3-7-2-6-5-4-8 firing order.

Now I’m thinking i should pull the starter to look at the block casting number to confirm manufacturing year.

 

[DirtDonk]

Don’t bother to pull the starter yet.
With your whistle (or finger tip for that matter), simply find the compression stroke on number one cylinder (doesn’t have to be TDC) and then switch it over to either cylinder five or three.
See if the next one to build pressure goes with your firing order.
Should show itself when it comes up in the next 90° of crank rotation.

 

[danroot]

Just because the 302 came out of a 94' doesn't mean it's a 94' block. Almost made that mistake in my Bronco. Turns out my 302 is a crate engine so the 1-3-7-2-6-5-4-8 is correct. What if your 94' 302 is pre 94'? That sure would cause bangs even if TDC was set correctly.

 

[jeffncs]

Just because the 302 came out of a 94' doesn't mean it's a 94' block. Almost made that mistake in my Bronco. Turns out my 302 is a crate engine so the 1-3-7-2-6-5-4-8 is correct. What if your 94' 302 is pre 94'? That sure would cause bangs even if TDC was set correctly.

Agreed. I’m going to open a beer and check if 3 of 5 drops after I reset TDC on #1.

I bought the engine from a guy that only bought it for the aftermarket headers that were on it. Spotless inside but I have no clue on the cam…I’ll solve that mystery shortly!

 

[jeffncs]

She’s alive!!! Determined the cam is the 5.0HO and re-checked the dizzy. I somehow dropped it 45° out of TDC. Reset it and she fired right up! Purrs like a kitten except for the garbage carb that’s still running super rich!

Here’s the kicker…. Recall the massive backfire? I found out why it sounded like a shotgun blast…. More of an explosion. Heck this craziness out!



The muffler exploded! No joke! Split the entire muffler front to back along the main seam!

 

[73azbronco]

yeah thats a first

 

[gnpenning]

She’s alive!!! Determined the cam is the 5.0HO and re-checked the dizzy. I somehow dropped it 45° out of TDC. Reset it and she fired right up! Purrs like a kitten except for the garbage carb that’s still running super rich!

Here’s the kicker…. Recall the massive backfire? I found out why it sounded like a shotgun blast…. More of an explosion. Heck this craziness out!

View attachment 962090 View attachment 962091

The muffler exploded! No joke! Split the entire muffler front to back along the main seam!

Glad you got it running.

You went the extra mile checking out your muffler. Looks good so you can put it back together .

 

[danroot]

Yikes! First for me as well, haven't seen a muffler pop like that. Glad you got things sorted out.