Trouble starting rebuilt 351 - Success!

[DirtDonk]

Of course, if you're running EFI and want new, here ya go:
http://store.prestoliteperformance.com/hot-items/garage-sale/dist-ford-5-8l-tfi-remote-mod.html

If you're carb'ed, there's one for that too I think. Don't have the link handy though.

Paul

 

[thegreatjustino]

OK, still about to push the Bronco off the cliff on this one. Compression test was at 130 on all cylinders. I pulled the distributor and per Viperwolf's instructions via PM, I tested it for spark, and it fires/sparks eight times per revolution, so that seems to be in order.

Once again, I removed all of the spark plugs and turned the engine over by hand, putting my finger in each of the spark plug holes to see when they build compression. They do in fact build up compression against my finger after the intake valve closes in the 1-3-7-2-6-5-4-8 firing order, so I know my plug wires have been hooked up correctly this whole time.

I have tried two distributor caps, two rotors, two pertronix modules, three different coils, two sets of plug wires, two sets of plugs, two different carburetors, and have adjusted the timing every conceivable way and it still has the no start/run rough for a second before dying issue.

I'm at a loss. I have started engines that had no distributor, plugs, or plug wires hooked up to them before and they have always fired right up after getting #1 to TDC, the distributor in, and the plug wires in the correct order. This one is driving me bananas.....

 

[Viperwolf1]

OK, still about to push the Bronco off the cliff on this one. Compression test was at 130 on all cylinders. I pulled the distributor and per Viperwolf's instructions via PM, I tested it for spark, and it fires/sparks eight times per revolution, so that seems to be in order.

Once again, I removed all of the spark plugs and turned the engine over by hand, putting my finger in each of the spark plug holes to see when they build compression. They do in fact build up compression against my finger after the intake valve closes in the 1-3-7-2-6-5-4-8 firing order, so I know my plug wires have been hooked up correctly this whole time.

I have tried two distributor caps, two rotors, two pertronix modules, three different coils, two sets of plug wires, two sets of plugs, two different carburetors, and have adjusted the timing every conceivable way and it still has the no start/run rough for a second before dying issue.

I'm at a loss. I have started engines that had no distributor, plugs, or plug wires hooked up to them before and they have always fired right up after getting #1 to TDC, the distributor in, and the plug wires in the correct order. This one is driving me bananas.....

Only thing left to fail is carb.

 

[broncnaz]

Who rebuilt the 351W? its possible that the timing gears were not lined up correctly when it was installed.

 

[lars]

Maybe I'm missing something, but is it getting fuel from the fuel pump? At this point I'd be trying the ether-aimed-at-the-carb trick. In other words, fuel supply failure? Just guessing...

 

[stubby1]

make sure your not 180 out on the dist, It could happen i have done it and have built a few dozen engines, also make sure you wired the cap in the correct direction. i believe ford is counter clockwise rotation need to go look at mine just some food for thought

 

[thegreatjustino]

Fuel delivery is about the last thing on my list to try. This engine came out of a Bronco with an electric fuel pump, but I am still running a mechanical one. I bolted the old pump in, but I don't know if the guy who built the engine put the eccentric on the end of the cam. That could be my problem there, but I would think the engine would run for at least a bit off of the gas I am dumping in the carb to prime it.

Distributor is not 180 off. I have taken it out and re-installed it four or five times now. Plug wires are hooked up correctly as well. Engine turns clockwise, distributor turns counter clockwise. Compression builds in the same order as the plugs are hooked up.

 

[lars]

Let me describe to you how much I loathe and despise mechanical pumps. And that's based on experience with airplane engines, not just old 302's. Oh... never mind...

 

[DirtDonk]

...That could be my problem there, but I would think the engine would run for at least a bit off of the gas I am dumping in the carb to prime it.

If you're pouring it down the throat of the carb, then no, it would likely die in a matter of a few seconds every time. And usually will.
If, on the other hand, you're filling up the float bowls, then yes, the engine should run for as little as a minute, but likely for a couple of minutes. And it would act normal when you hit the gas, until it ran out of fuel again.

That's the expected results anyway.
Yours may vary!!!! ;D

Paul

 

[DirtDonk]

Of course, that's easy to check also. If you look down the venturi and roll the throttle lever back, you should see a good solid squirt of fuel each and every time out of the nozzles.

Paul

 

[thegreatjustino]

Fuel would help wouldn't it? Apparently the engine builder left out the fuel pump eccentric because he was using an electric fuel pump. After getting an old one I had in the garage working and wired in, the engine fired up with minimal effort. Two weeks of pulling my hair out because of a silly missing part. %)

 

[gr8scott]

Fuel definitely helps! Glad you got it worked out!

 

[dave vh]

congrats on figuring it out . way to stick with it

 

[75Denver]

Can someone PLEASE post a pic of the fuel pump eccentric?? This is the same exact symptom mine is doing and once had an electric fuel pump. I just put a mechanical back on it to try and run as close to factory as possible. Also, my carb is completely dry and barely sputters if I fill the bowl up with gas....same reason you think?

 

[thegreatjustino]

The fuel pump eccentric is a round piece that is installed offset in the end of the cam.

You can see it installed in this picture - here it's pointing toward the bottom of the timing chain cam gear

The eccentric itself looks like this:

If you can get your finger in the mechanical fuel pump hole, you should be able to feel if it is in there or not.

 

[DirtDonk]

I just put a mechanical back on it to try and run as close to factory as possible. Also, my carb is completely dry and barely sputters if I fill the bowl up with gas....same reason you think?

Maybe yes, but you have another issue as well. If everything else but the pump is correct, you can fill up the bowl and have the engine run normally for several minutes at idle.
If it's not doing that, it's not the pump. Even without the pump, if you have fuel in the carb, it should run.

Now, as for the pump, if it's not pumping, it could still be the eccentric (or lack thereof) causing the issue. Of, if it's a newly installed pump, some just take a lot of work to prime initially. Once they get primed, they pump like normal.
Is this what you just did? New pump?

Paul

 

[75Denver]

Maybe yes, but you have another issue as well. If everything else but the pump is correct, you can fill up the bowl and have the engine run normally for several minutes at idle.
If it's not doing that, it's not the pump. Even without the pump, if you have fuel in the carb, it should run.

Now, as for the pump, if it's not pumping, it could still be the eccentric (or lack thereof) causing the issue. Of, if it's a newly installed pump, some just take a lot of work to prime initially. Once they get primed, they pump like normal.
Is this what you just did? New pump?

Paul

I did put on a new pump. What I found when I poured gas in the bowl was that it instantly leaked out of the gasket between the carb and the manifold riser. So I took the carb off needing to replace the gasket and found that the fuel filter/hose going into the bowl wasn't even touched with gas from the fuel pump. Maybe the I need to fill the carb up more w/ gas and then hope the engine tuns enough to activate the pump. Also, is there ANY OTHER way to find out if the engine is equipped w/ or w/o an eccentric? What's the purpose of this part and why would it be left off if the engine's fuel supply was built to be electronically controlled? I'm learning as I go.

 

[DirtDonk]

I did put on a new pump. What I found when I poured gas in the bowl was that it instantly leaked out of the gasket between the carb and the manifold riser.

If you were getting any of the fuel down into the throat of the carb, that leaking might have been semi-normal. Probably still a good idea to have checked/replaced the gasket though.

So I took the carb off needing to replace the gasket and found that the fuel filter/hose going into the bowl wasn't even touched with gas from the fuel pump. Maybe the I need to fill the carb up more w/ gas and then hope the engine tuns enough to activate the pump.

Absolutely.
It's not guaranteed of course, but the pump stands a much better chance of self-priming if the engine is spinning it up faster.

Also, is there ANY OTHER way to find out if the engine is equipped w/ or w/o an eccentric? What's the purpose of this part and why would it be left off if the engine's fuel supply was built to be electronically controlled? I'm learning as I go.

What engine again? It would not merely have been "left off" of a late model engine, it would never have been designed into it in the first place. It's sole purpose in life is to actuate the lever on a mechanical pump. Late model engines have used electric pumps ever since they went to Fuel Injection in the '80's.
The ONLY reasons for one to even be there is if the engine was originally equipped with a mechanical fuel pump (like an original Bronco engine) or if the PO/builder of the engine put one there. They even re-cast the front cover to eliminate the hole and mounting boss for the pump. So the only way to mount a mechanical pump is to replace the timing cover with the correct (older) cover.

Otherwise, Ford would never spend the .75 cents per part, nor the 10 seconds in man-hours to put them into literally millions of vehicles that would not be using them.
Saves a ton of money that way.

Paul

 

[75Denver]

On my way to pick up a new gasket. When filling the carb up w/ gas, is there an amount I need to be wary of?? Will too much create a problem if the lines are dry? Also, the engine is a 302 (not the original...decoded and it came up as a 78 Lincoln Cont 302). So in other words, it never was intended for one and probably never had on installed when rebuilt?

 

[DirtDonk]

No, a '78 engine would have had one originally. If it's not there, someone took it off.
The Continental would have had the 2-piece as shown in the lower pic above. The cop-car and ambulance versions would have been 1-piece, like in the upper pic.

The only way to know is either to spin the engine and "feel" the pump, or pull the pump and stick your finger in there.

Paul