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Starting issues

2K views 16 replies 5 participants last post by  TNprogrammer 
#1 ·
So I finally got my new fuel tank installed in the '78 this past weekend. The car had sat for about 6 months after I pulled out the leaky original. Amazingly, the battery was still good as I had disconnected it and kept it on a tender. Once the tank was installed we put about 10 gallons in and poured a small amount of fuel in the carb. She fired right up. From the smell it did seem to be running a bit rich.
We buzzed around the neighborhood for about 10 minutes and parked it. About 15 minutes later I tried to start it and it would crank and crank but not start. It felt like it was flooded. I sprayed some ether in the carb to help evaporate any excess fuel, let it sit about 10 minutes and it fired up.
Here's where my question comes in....could it be that having the new tank, sending unit with new fuel filter on the end and new clean soft fuel lines at the top of the tank is causing too much gas to get to the carb? We had tuned the carb before the tank started leaking and like I said it smells a little rich now. Should I try leaning it back a little at the carb? Once the car starts it seems to run great, although the smell is a tad 'fuely' :)
As always, thanks for your input.
 
#2 ·
Start with the easy stuff first. What carb? The floats regulate the fuel flow into the carb. If you think too much fuel is pushing through then I'd start with the float/s. When fuel sits in carbs it can gum everything up, and it probably wasn't squeaky clean before it sat either.
 
#3 ·
It's a Q-Jet. newly rebuilt when the engine was rebuilt 5 years ago, but like you say, sitting fuel is never good. The weird thing though is that I only have trouble starting it soon after it was previously run. After it has sat a while it starts like a champ. I ran it for a few minutes last night. It will be interesting to see if it starts right up after I get home today.
 
#4 ·
It's been about a week now and the car starts perfectly about 80% of the time. Other times I can crank and crank but it won't start. For instance, I came home today about 5pm and cranked it and it started like a brand new car. I ran it for a couple of minutes and turned it off. Then I came back home tonight about 9pm planning to go for a little ride in the cool night air. It cranked and cranked but wouldn't start. I sprayed some ether in it and I'll let it sit for about 15 minutes and try again.
Could the starter be going bad? I've had starters go bad in my DDs before but it's been a while and I can't remember the symptoms. Can one of the local car parts retailers check a starter to see if it's good?
 
#7 ·
My thought is the coil. In pre HEI distributors the coil is mounted to the intake and there's a short coil wire from the coil to the center of the distributor cap. In an HEI distributor, the coil is IN the cap. Both can go bad. Both are fairly easy to replace, and unfortunately, it's not really testable.
 
#8 ·
Thanks for the input. Mine is HEI. And forgive my ignorance because the ignition system is one of those areas where I still have a lot to learn. If the coil is going bad would that cause problems only on startup? Because once it starts it runs really well. It started both times I tried it yesterday and I went for a couple of short (8-10 mile) drives. It idled fine at red lights and had good pickup (for a 1978, 190 HP engine that is).
 
#9 ·
Check the wiring connectors at the distributor. Look for frayed wires or connectors that are loose.

Worked on a 1970 Chevelle, 502 car with HEI. Same type of issue. Frayed wire at the distributor connector was causing intermittent connectivity. Put on a new terminal, slipped that into the connector, hooked it back in..... problem solved.
 
#11 ·
Glenn,
My son used an MSD coil and other parts on his 2 75's. The first one did have a coil failure years ago. He drove 45 miles to a cruise night, walked around for an hour and the car was dead. Everything checked out and about another hour later right before calling for a flat bed it fired up. He got home and replaced the coil and never had a problem like that again.

Are you getting gas when this happens? Can you see the gas when you open the throttle and look in?
 
#12 ·
I haven't visually checked for gas when this is happening, but from the smell I thought at first I was flooding it. It definitely smells gassy after turning over several times without firing up. I'm also going to check the fuel filter at the carb this afternoon when I get home.
 
#13 ·
I recommend HEI regularly for street cars. HEI is usually a rock solid distributor. I've purchased used ones at swap meets for $20 on multiple occasions, took them home cleaned them up and they fire right off. Can't beat them if building on a budget.

I run one in my Jeep because of the reliability. I can't remember actually having a problem with the electronics. Although I did replace a coil one time. I've actually rebuilt more of the MSD units than the factory HEI, in all fairness the MSD's were in race cars.
 
#14 ·
Don't higher revving engines get the most benefit out of MSD distributors? Seems like I read that somewhere before. So having them in race cars would make sense I guess. If you guys say that HEI should be reliable then I'll go with that. Even though mine doesn't have many miles on it at all it IS seven years old. I didn't get the chance to pull the cap and check it out this afternoon. However, the vette fired up twice for me just fine. What exactly am I looking for once I remove the cap?
 
#17 ·
My friend and I tore into things today and discovered a few things. After the car started fine for the last week it would not start at all this morning. After testing, we found there was no spark at the plugs. Using a multimeter we tested the connector where the battery wire connects to the dist. It was right at 12 volts, so we figured the issue was in the dist. Once we looked at the coil we saw that the wires were a little melted right where they connect to the coil. Also, the plastic where the wires connect was a little melted.
We ran to the local parts store and picked up a new coil and rotor cap. Once we installed the new parts the car fired right up with no hesitation. However, we could hear a pretty loud crackling noise. We knew that something was sparking. We pulled the cap off the coil and cranked the engine. The tach wire coming off of the coil was arcing like crazy. We couldn't figure why in the world it would happen unless the new coil was just bad. I noticed a part inline with the tach wire going back toward the dash. It is pictured below.


After looking it up I found that this is called a tachometer filter. So my question is this....if this part goes bad, could it cause voltage to back up at the distributor and fry things? The one on my car looks very old.
We couldn't come up with any other reason the tach wire would be arcing like it was.
 
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