Hard time starting up.

[dewiant]

Hi Guys,

For many month I'm working on my 351C to startd up properly.

I used to have an issue with starting up on warm engine. No problem with cold one, started really good but warm one didn't want to start at all. The only thing that helped with firing up was to connect a battery booster.

Recently I have replaced my OEM starter with PowerMaster XS 9503 one. It helped a lot. Now I can start on cold (as previously), I can start hot engine (right after I turn off the engine, I can turn it on again without any issues).
The problem occurs when the engine is cooling for some time (turned off) like an hour or two, and the I try to start it up again.
The engine is rotating, ste starter is working but nothing else is happening. It dosn't matter if I pump up a fuel before trying (like i do on cold one, 3-4 pumps of gas pedal) or I do nothing (like on hot engine).
I am able to somehow start up on lukewarm engine while pressing gas pedal from time to time when the starter is rotating engine but it takes time and doesn't sound right...

So far i did:

1. Replaced Starter to the PowerMaster 9503 XS
2. Replaced battery to 74 Ah / 680A
3. Replaced Solenoid
4. Replaced Distributor
5. Installed Pertronix system + their coil
6. Replaced spark plug's wires

What else can/should I do? What may be the reason for the problems?

Thanks for any hints!

Cheers.

 

[Tnfastbk]

If the engine is turning over normal, I would think its a fuel or spark issue. When the car will not start is the time to check for both. You may need some help with the process. If its lazy to turn over it could be a timing issue.

 

[Stanglover]

When I had some hot starting issues on my 71 M code 4V, it proved to be fuel evaporation in the carb. This was cured by two things, blocking off the exhaust cross over passages in the intake ( a big job though) and adding a 1" thick fiber spacer under the Holley 670 carb. There is a way to block a lot of the heat under the carb on a stock intake and that is to screw in a plug in each hole in the passage under the carb. This of course is on a 4V intake, you don't say what you have 2V or 4V. As I'm not too familiar with 2V, I assume it would be the same.
You say you installed a new distributor with Pertronix system. Can you give more details on that please. Also what is you initial timing set at and your total mechanical timing. It ought to be around 34 -36 degrees, no vacuum.

 

[dewiant]

If the engine is turning over normal, I would think its a fuel or spark issue. When the car will not start is the time to check for both. You may need some help with the process. If its lazy to turn over it could be a timing issue.

It is turning normally. I can't think of any difference in fuel or spark when the engine is lukewarm thank when it's cold or very hot right after the drive... For that I'll need someone who is better with mechanical topics... :/

When I had some hot starting issues on my 71 M code 4V, it proved to be fuel evaporation in the carb. This was cured by two things, blocking off the exhaust cross over passages in the intake ( a big job though) and adding a 1" thick fiber spacer under the Holley 670 carb. There is a way to block a lot of the heat under the carb on a stock intake and that is to screw in a plug in each hole in the passage under the carb. This of course is on a 4V intake, you don't say what you have 2V or 4V. As I'm not too familiar with 2V, I assume it would be the same.
You say you installed a new distributor with Pertronix system. Can you give more details on that please. Also what is you initial timing set at and your total mechanical timing. It ought to be around 34 -36 degrees, no vacuum.

I have 4v,holley as well. Don't know the model tho.
Not sure what more info do you need for the Pertronix? The coil as well as module are connected to 12v (no resistor wire between).
My timing for idle is 10 atm. I don't really know the timing when it's 3k rpm.


Sorry for not really specific answers. It's my 1dt classic car and I'm still learning therefore I use a lot of help of car mechanics who do many setups for me.

 

[73inNH]

Like Stanglover, I had a fuel evaporation issue. I mostly fixed it by adding a phenolic spacer under the carb.

I've heard Air Gap manifolds help, but I haven't tried one.

 

[Stanglover]

It is turning normally. I can't think of any difference in fuel or spark when the engine is lukewarm thank when it's cold or very hot right after the drive... For that I'll need someone who is better with mechanical topics... :/



I have 4v,holley as well. Don't know the model tho.
Not sure what more info do you need for the Pertronix? The coil as well as module are connected to 12v (no resistor wire between).
My timing for idle is 10 atm. I don't really know the timing when it's 3k rpm.


Sorry for not really specific answers. It's my 1dt classic car and I'm still learning therefore I use a lot of help of car mechanics who do many setups for me.

No problem. I was referring to whether the Pertronix is a module # 1, 2 , or 3. 1 and 2 are both good, but I had trouble with a P 3. Not electrically, but mechanically. I'll not elaborate here, but imo, they are crap.
As for your Holley carb, there should be a set of numbers on the horn area. Those can be used to identify the carb.
Starting your timing at 10 should be a good place to start. You also didn't mention what distributor you have though. My personal experience is limited to a stock Ford dist., but no matter what, your total mechanical timing, no vacuum, should not go much beyond 36 degrees BTC. Others are far better able to help with this, but I'll help where I can.
Good luck and remember, there are NO dumb questions.

 

[Stanglover]

Like Stanglover, I had a fuel evaporation issue. I mostly fixed it by adding a phenolic spacer under the carb.

I've heard Air Gap manifolds help, but I haven't tried one.

I was watching a video on heat cross-over blocking. Even most aluminum intakes have them, but in the video, they just added a thin piece of metal under the gasket, coving the heat port. I also did this as well as blocking the intake directly, but I chose stainless steel, not aluminum (bad choice) or ordinary steel from an old oil can as in the video.

 

[70sElvis]

Had the same thing but mine was on a Edelbrock carb and turned out one float was set a little too high allowing fuel to slowing drip in and flood my engine. Had to hold down the pedal to the floor to crank until I finally had time to adjust the floats. just my 2 cents.

 

[Don C]

A bad power valve diaphragm will leak fuel into the intake manifold, as will a porous carburetor casting. This results in two problems, puddled fuel in the intake and an empty carburetor.