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Discussion Starter · #1 ·
The last two days I've barely been able to get my stock 78 started. It takes about five long cranks but once started it sputters five seconds and then runs as normal as always. What freaked me out this last time was after the first crank a bunch of white smoke billowed out of my grill area. That has never happened before. I have a K&N cold air filter so I'm thinking the smoke came from there but don't know why. I have a 1 1/2 year old fuel pump, fairly new rotor and dist cap and the NGK plugs and wires only have about 4,000 miles on them. Any ideas why it would now be so hard to start but runs fine? Btw, cold weather isn't a factor as I live in LA.
 

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check the connections to the fuel pump control relay and the fuel pump relay. also check the cold start system, thermotime, connections to those, ect...
to test to see if the fuel pump starts when the key is in the start position, remove the spade connector to the starter. turn the key to the on position, the fuel pump should be off. now turn the key to start, you should hear the fuel pump running. if it runs in the start position, all is well.
 

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i live up in the san fran area and mine gets hard to start in the 40's
i set up a manual switch for the cold start valve. it starts right up
after giving it a whif of gas
 

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Discussion Starter · #4 ·
really cold weather

bakachan,

I used to own a couple 76's when I lived in Kansas and Rochester, NY and that is cold weather especially the cold lake effect wind off of Lake Ontario. Neither car never once didn't start on the first crank which is what I loved about them. I used to start them up in the winter in my complex parking lot, take the key out of the worn ignition, lock the doors and go inside for another ten minutes while the Z heater melted all the ice and snow off the windows. I prefer the LA weather now though.
 

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Discussion Starter · #5 ·
what next?

Thanks johnb510. You always give good advice. Went out to start it today and it turned over on the third crank, sputtered for about five to ten seconds and then ran fine. I checked that the fuel pump is working and I cleaned and reseated the temp sensor and thermotime switch. I checked my plugs and injectors also but figured there wasn't anything wrong with them since the car runs fine just doesn't like to start.

It started first crank after all this but then again it was already warm.

If not resolved I'm not sure what to check next. The 78 FSM pretty much tells you to troubleshoot everything for not starting and unstable idling during warmup. Maybe I'll learn how to use the cheap multimeter that came with my electrical kit.

Thanks,
MTP78Z
 

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Re: what next?

Follow johns advice. I still think the problem is in the thermotime/cold start valve area.

Another thing to look at is your ballast resistor. Make sure that the wires coming from your ignition module to the ballast resistor are tightly crimped (or bolted down). These get dirty and can interfere with it's ability to start.

In theory, during cold start, a couple of things happen to increase it's chances of starting. One is the cold start valve, which squirts a shot of fuel in the intake during initial starting attempts. The other is the ballast resistor. While starting, the ignition module sends it's 12 volts to the middle contact of the ballast resistor, where it drops less/no voltage on it's way to charge the coil. This allows for hotter spark during the start cycle. Once the car starts, the ignition module sends it's 12V to the end of the ballast resistor, where half the voltage is dropped on it's way to charge the coil.

Having said all that, it is less likely that your problem is ignition related, and more likely it is fuel/CSV/thermotime related. Check for dirty contacts in the connectors and the sensors. Make sure they are plugged into the right places (don't laugh, it happens). Minor possibility that your FI relay is faulty or dirty (can be opened and cleaned). Have you checked that fuel is actually coming out of the CSV?
 

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Discussion Starter · #7 ·
Re: what next?

I haven't checked that fuel is coming out of the CSV cause it is a pain in the butt to take out with the air regulator and other hoses in the way.

I'm a little confused as when the CSV actually shoots gas out. The 78 FSM says fuel is injected when the water temp is below 57 to 72 degrees which would lead me to believe that nine months out of the year here in LA my cold start valve is never used. What concerns me is why it would now be so hard to start when the temp is only 60 or so and more importantly why would white smoke come billowing out back through the intake and out my air cleaner. I can see it not starting because it wasn't getting enough gas but why the backfire of smoke? Of course, if the termotime is just plain dead I don't know what the impact of that would be on the rest of the system.

Also, about a month ago I removed my air compressor fan belt and somehow disconnected the water temp sensor. In this case the car started right up and only ran rough. It's now the opposite where it's hard to start but runs fine.

One thing that was odd that happened yesterday was when I tried to start it I released the key back from the start position to the on position and I definitely heard the electric fuel pump continuing to hum. It shouldn't have done that from what I understand and that is the first time that's happened. I can't remember if it stopped cause I turned the key off or it stopped on its own.

I'm not sure what the ballast resistor is but it's now on my list to check. According the the FSM I pretty much have to troubleshoot every component in the FI system to figure this out. Someone suggested a blown head gasket but my oil is clean and it doesn't smoke out the back and it runs fine after idling about five seconds.

Thanks for your help.
 
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