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Perhaps the most mysterious Engine problem ever! lol


Old 09-14-2004, 03:25 PM
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Join Date: Sep 2001
Location: Week-Philly, Weekend-Dirty Souf Jerz
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Arrow Perhaps the most mysterious Engine problem ever! lol

whoever can figure this one out, i'll owe ya big time! haha

the truck....
1985 Ford F-150
302 V8
140,000 miles
2 bbl carb

the history....
always had problems with stalling out, especially cold weather
driving with 2 feet is second nature to me in that truck. LoL! one for the brake, and one for the gas to keep the RPM's up when coming to a stop or in cold weather (and no it just doesnt need an idle adjustment, believe me, its not as simple as that lol)

the repairs....
just put a new fuel pump on, new plugs, wires are only 2 years old, same with distributor parts, air filter and pcv breather just replaced, also 2 weeks ago we yanked off the crappy azz stock 2 barrel carb and put on a holley 4 barrel 600 cfm carb. the new carb didn't have all the vaccum lines for the emissions in 85, so.....we yanked off all the emissions stuff, EGR plate, smog pump, etc. so eliminated all those vaccum lines associated with the pollution control. truck never passed emissions anyway and picked up some power.


twice so far (once before the new carb, and once after)
truck was warmed up, drove somewhere, it sat for about 15-20 minuts, go to start it back up and nothing

jumped'll crank but wont kick over
starter fluid...nothing...crank but no start over

check the coil with my volt tester, shows its getting power

pull a spark plug, put it back in the boot, and have somebody crank the truck so i can see if i'm getting spark. truck fires right up on 7 cylinders!
shut it down, put the plug back in, and she starts right up but with a NASTY valve tap (never had a tap before, except these 2 times, and it only does it for about 5 minutes)

keep in mind that exact situation happened TWICE! once before the new carb, and once after. pull a plug and it fires right up. WTF could it be? haha

it has my mechanics stumped here...but maybe somebody can shed some light or suggestions for me.

probably taking the 4 barrel carb back and going for holley fuel injection too, but i doubt that'll solve the whole problem

Thanks in advance....i challenge somebody to solve this one! haha
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Old 09-14-2004, 07:37 PM
Join Date: Dec 2003
Location: Butler,PA
Posts: 67
Not sure about the funky starting but the last one I had that I HAD to drive with both feet (I do anyway) was a '71 Torino with a 302 in it. Changed everything on the motor at least 3 times including carbs, nothing would keep it running. Finally sold the car and the guy pulled the motor, cam was broke in 2 places. Still ran and plenty of power, to this day I'm not sure why tho.
Sounds like your ignition module is the most likely culprit here but it could also be in the throttle position sensor.
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Old 09-15-2004, 05:36 PM
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Location: Lockport, NY USA
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Does the cranking speed sound normal?? What is your timing set at?

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Old 09-17-2004, 10:00 AM
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Location: Ventura, California
Posts: 3,083
Did the new carb solve the cold idle/stalling problem, or are we trying to figure that out, too?

The starting problem is your ignition module. The coincidence with pulling off the spark plug was just that, a coincidence. You can test it next time it's cold by hitting the module with a hair dryer on low for a few minutes, and then see if it starts. If it won't, it's the module.
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Old 09-21-2004, 10:26 AM
Join Date: Dec 2003
Location: Butler,PA
Posts: 67

Interesting idea for testing the module, never thought of that. I'll have to keep it mind next time I think I've got a bad one.
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Old 09-22-2004, 11:12 AM
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died on me a few more times since i've posted lol

replaced the ignition coil, started right up but still runs like crap

pulled the carb off and returned it

holley "pro-jection" fuel injection system gets here thursday
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Old 09-23-2004, 12:11 AM
Join Date: Apr 2004
Location: Wabbaseka, AR
Posts: 12
Well, you have done a pretty good job so far of trying to single out the problem. I would have to say that it could only be a few more things. First, try the ignition module. Second, have the timing checked by someone that would know what it should be set on. Does the engine turn over slowly when cranking it, kinda like the battery is almost dead? If so, then it could definately be the timing. I have a 93 F-150 w/ 302 and I have about 198000 miles. At about 150000 miles, I had to put a new timing chain and gears in the engine. I have heard of similar problems before when the distributor shaft was broken. Also, I dont know about a Holley, but on an Edelbrock I have, if a certain vacuum line isnt hooked up or plugged off where it cant suck air, then engine will die. Hope something here helps.

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Old 09-24-2004, 11:11 PM
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Location: Week-Philly, Weekend-Dirty Souf Jerz
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all vac lines are good. not many left after ditching the EGR and pollution/emissions stuff

timing is set back to stock, played with it a few degrees around, and ran best at stock when it did run

battery cranks fine. brand new redtop in there.

ignition coil just replaced
ignition module thing replaced 2 years ago

holley projection fuel injection system got here thursday. i'm going to start on it tomorrow. probably take me a few weeks to get it done cuz i can only work on it on weekends.

projection fuel infection has begun
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