1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks Discuss the Early Eighties Bullnose Ford Truck

Engine Drags when hot!

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Old 02-20-2011, 07:36 PM
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Engine Drags when hot!

I have a 1984 F-150 with 302 engine that after you run it for several miles and turn it off it will not start until it cools down for 15 minutes or so. The engine was rebuilt in 2003 and has run fine until lately this problem has developed. I was told the starter needed to be replaced. I changed it and drove it yesterday for about 45 minutes and same thing. The engine problally has 20,000 miles on it since rebuild. Is there a way to determine if the timing is off without a timing light? Thanks for any advice.

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Old 02-20-2011, 11:34 PM
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'84 302... I think this is a computer-controlled engine? If so, see if you can pull any codes,
the ignition system is supposed to retard the timing to make for easier starting, yours may
not be doing that.
 
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Old 02-21-2011, 08:33 AM
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About two years ago, my truck did exactly what yours is doing. I replaced the starter like you did, and the problem was still there. The problem ended up being a bad ground. Where the negative battery cable attaches to the engine block was a little loose and heavily corroded with rust. I cleaned that up and the problem completely went away. I kid you not, My truck now actually starts up faster then my 1998 Jeep Wrangler and my wife's 2001 Mustang!

Check both battery cables and your starter cable. If they are original to the truck, go ahead and replace them all.

Good luck!
 
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Old 02-21-2011, 08:35 AM
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No way to check the timing without a timing light. If you are going to do your own work, a timing light is one of the investments you will have to make. It would be way cheaper to buy it than take it to a garage.
 
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Old 02-21-2011, 02:36 PM
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Where does the ground attach to the engine? I replaced the cable that goes to the starter a few years ago but not the ground.

Thanks Railroadman
 
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Old 02-21-2011, 02:52 PM
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Originally Posted by railroadman
Where does the ground attach to the engine? I replaced the cable that goes to the starter a few years ago but not the ground.

Thanks Railroadman
On my '85 302, the ground cable goes attaches (by a cable clamp) to the frame on the right side of the engine and a bolt that attaches the transmission cooler lines to the engine behind the alternator. My alternator attaches lower because I have an AIR pump above.
 
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Old 02-21-2011, 04:15 PM
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Originally Posted by railroadman
Where does the ground attach to the engine? I replaced the cable that goes to the starter a few years ago but not the ground.
The ground that I had a problem with bolts to the engine block on the passenger's side toward the front from the negative battery cable. Just follow the path of your negative battery cable. This is how it was stock on my 1985 F150 302.

It shouldn't be a timing problem if it ran fine after the rebuild in 2003 until recently and you didn't change it.

Check your battery cables and the negative battery cable ground. Take the bolt off of the engine block where the negative battery cable bolts to and clean the rust and corrosion off the bolt, block, and the end of the battery cable where it bolts down to the block. Reattach tightly and your problem will probably go away.
 
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Old 02-21-2011, 07:22 PM
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Got it off, will pick up a new one tommorrow. The old one looks like it may have corrosion where the eylet is fastened. Will post after install new one and tested.
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Old 02-23-2011, 04:34 PM
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Update on Engine Drags when Hot

Well i replace the ground cable to the block. Drove it around for a while and turned it off and it cranked right up. Great I thought. I went to the gym this morning and when i got there i thought i would try it again and be sure my problem was gone. Same problem. When i came out it cranked right up. I am reading the instructions on installing the starter and it mentioned checking voltage when try to crank should be a minium of 10 volts. If less could be a starter relay. Not sure where that is but looks like some kinda plug in type relay looking at it on line at advance auto. Any idea's?
Thanks Railroadman
 
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Old 02-23-2011, 04:52 PM
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Could be a bad starter or not enough voltage to the starter. Have the battery tested first. If thats ok you can check voltage to the starter and compare it to battery voltage while cranking (voltage drop). Sounds like the starter is heat soaking and needs to be replaced, so you can try that if you dont feel comfortable with testing the system. (Got a voltmeter?)
 
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Old 02-23-2011, 04:56 PM
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I merged the two threads, it's easier to go look at the history this way.
 
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Old 02-23-2011, 05:02 PM
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Originally Posted by ctubutis
I merged the two threads, it's easier to go look at the history this way.
Thanks, I had to look back at the old one to see what was going on. It also may help someone in the future doing a search.
 
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Old 02-23-2011, 08:29 PM
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Get an Amp Draw test on your starter

There isn't really much that can cause this kind of problem... either the engine has
become hard to turn over (not likely from what I'm seeing here) OR the starter motor isn't
getting enough power with a warm engine OR the starter motor is defective.

There isn't much to this setup... electricity flows battery -> solenoid -> starter -> back to
battery ground.

I would take it to a full-service gas station, maybe an auto parts store that does this test,
but drive it around and warm it up and take it to a place that can do an "amp draw" on the
starter while the problem is manifesting itself.

I have my header tubes plum next to my starter motor and don't have this problem, I
more suspect bad electrical continuity in your truck than anything.

Starter solenoids burn out, they're just relays that connect the two fat wires together to
supply power to the electric motor and the contacts inside burn up.

Also, I'm assuming your engine isn't overheating or running hot....
 
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Old 02-23-2011, 09:16 PM
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Sorry about the 2nd post. Should have added to the first, but no the engine is not running hot. I have a set of sun pro gauges and it is holding around 190. I replaced the starter last week but i did think of taking it to advance and let them put their diagnostic machine on it. I appreciate everyone's thoughts on this problem. I am trying on thing at a time so i will know when i hit on the problem.

Railroadman
 
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Old 03-07-2011, 03:01 PM
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Update

I was talking with a friend of mine and was sharing my problem with him and his suggestion was this; due to the salty air here in florida that he had seen the same problem before where the vacume advance would stick or hang up. He suggested that i squirt some wd40 on the plunger and around the shaft where the vacume advance moves. I did and guess what? The engine has cranked fine ever since. It has not let me down the first time and seems to have a little more pep. Until it lets me down again i will consider this PROBLEM SOLVED!! Thanks to all of you for your comments and suggestions. Until my next problems shows up.

Railroadman
 


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