Motor doesn't start...?
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New User
Joined: Jun 2011
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Motor doesn't start...?
Hi, I have a 1970 Ford Highboy with what I believe to be a 390 in it. Bought it from the truck junk yard and drove it home. Replaced the carburator with a Holley and been doing some body work on it. Every time I started it it worked. Got new battery, gas in it, spark, and all wires are where they should be. I was trying to start it 2 days ago and it turned over but that was it. Hasn't started since. Anybody has any ideas ? Could really use some help.
Logistics Pro
Joined: Dec 2004
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From: Hemet ca.
Are you getting spark? Check coil. Are you getting fuel to the carb? Check fuel preasure. Are you sure the wires are where they're suppose to be? Check wiring again. Check out the distributor Really hard to tell without being there.
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Motor doesn't start..
Got spark, carburator is getting fuel, wires are where they supposed to be. Distributor has been checked. That's why I don't know what else it could be. Any other ideas or suggestions ? It ran before.
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Joined: Apr 2004
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Does it sound like its firing or is it just spinning over? If its just spinning over, my guess is it's ignition related.
It's some combo of fuel and fire just to get it started. Check that you get at least 5 PSI of fuel pressure. Also you can check the strength of spark from the coil with an ohm-meter. If the coil checks out check resistance in the coil to distributor cap wire.
What happens with a shot of starter fluid?
It's some combo of fuel and fire just to get it started. Check that you get at least 5 PSI of fuel pressure. Also you can check the strength of spark from the coil with an ohm-meter. If the coil checks out check resistance in the coil to distributor cap wire.
What happens with a shot of starter fluid?
Senior User
Joined: Jun 2011
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ya i have the same problem. its wiring. check to see if you have the plug wires to the right plugs and also check to see any wire splices. could also be a weak starter no?
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Cranky Old Guy
Joined: Mar 2008
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From: Raphine, Virginia
Check for voltage at + side of coil in start and run position. Got voltage, pull a plug and put the wire back on and hold tip to a good ground. Plug should have healthy spark. No spark, replace/check points. Coil will read 1.1-1.4 ohms across + and -, center post to either, minimum 7K ohms. That'll either find your problem or narrow it down a lot more.
Starting fluid usually works if you have spark, but look down throat of carb and move accelerator. Gas should shoot as soon as accelerator is moved. Postback with progress.
Starting fluid usually works if you have spark, but look down throat of carb and move accelerator. Gas should shoot as soon as accelerator is moved. Postback with progress.
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Fleet Mechanic
Joined: Oct 2005
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From: Gainesville, GA
You said you have spark but is it at the right time. When you ground the plug and crank the engine is the spark yellow or blue? It has to be blue or the coil isn't giving enough voltage to fire under pressure.
Cranky Old Guy
Joined: Mar 2008
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From: Raphine, Virginia
Missed that part.
Lead Driver
Joined: Aug 2003
Posts: 7,592
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From: **** hole San Jose ca.
If it tries to almost start at first but never fires up completely could be bad condenser. #2 If it has the round type contacts on the back of the ignition switch then I'd say it's the plug that plugs into the switch. Plus this will make it hard to start. Their is a replacement pig tail for this switch as they always burned these out.. You can try a jumper Hot wire right from the Battery to the + side of the coil while trying to start it. This should give it enough voltage to start up and run..my 2cents
orich
orich
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Motor doesn't start...
Thanks for everybody's suggestion. Checked the ohm on the coil, it was good. Changed the spark plugs again and put in a new condenser. Turned the key and it wanted to start really bad. We're getting closer to the problem. Spark plug wires are in the right firing order. Checking timing next. It's an old truck but I'm determined to get it running. Thanks again, keep you updated on the progress next weekend.
Freshman User
Joined: Oct 2010
Posts: 30
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From: Woodbridge CA
Check the voltage to the + side of the coil while cranking. Sometimes the resistor in the coil lead (if it has one) can cause problems like that.
Thanks for everybody's suggestion. Checked the ohm on the coil, it was good. Changed the spark plugs again and put in a new condenser. Turned the key and it wanted to start really bad. We're getting closer to the problem. Spark plug wires are in the right firing order. Checking timing next. It's an old truck but I'm determined to get it running. Thanks again, keep you updated on the progress next weekend.
Freshman User
Joined: Oct 2010
Posts: 30
Likes: 1
From: Woodbridge CA
There should be a bypass to full voltage while cranking (linked to the starter circuit on the ign switch?), then back thru the resistor after starting. I would still check the voltage at the coil while cranking.... a bad ground, excessive starter amperage draw etc can reduce the voltage to the coil when cranking the starter.