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Old Apr 9, 2005 | 12:42 AM
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'70_f-100's Avatar
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From: prescott valley, arizona
PLEASE HELP! vacuum problem

i just r/r manifold gasket, r/r all 4 of my vacuum lines, and rebuilt my carb and replaced valve rocker arm cover gaskets. all was fine truck has moved faster then it ever has. it had steady vacuum at 18Hg. so i decided to drive to phx from prescott this evening, and when i stopped for gas it cranked like the battery was about to die, and when it started it was sucking air really loud, and wouldn't idle. now i know this a tell-tail vacuum leak but when i popped the hood and checked everything out (vac lines and so forth) it looked ok. well considering my reasoning to come down to phoenix, i thought "hope we make it" and drove down anyway.
when i got here i called my mechanic friend and he said it might be a bad pcv valve. that they are a controlled vacuum leak.
please help, i have to drive back to prescott on sunday. so i have 1 or 2 days tops to figure this out!
 
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Old Apr 9, 2005 | 06:30 AM
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The only thing I can think of off hand at this time in the morning, Is get your self a can of WD-40 and spray around your gaskets and see if the engine picks up speed...

And Double check all your bolts to make sure there tight...Check the carb hold down Nuts....

Good Luck!

Russ
 
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Old Apr 9, 2005 | 08:32 AM
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<Quote> when i stopped for gas it cranked like the battery was about to die,

I cannot see how this problem would be a result from a vacuum leak. A hard, hot starting problem can be a result of your timing being off. If the spark is occuring too early it will be fighting the starter motor and make it appear as a weak battery. For some reason this type of problem occurs more when the engine is hot than when cold. In other words it cranks fine when cold but not when hot.

When you R&R'ed the intake did you set the timing up correctly?

Lee
 
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Old Apr 9, 2005 | 11:36 AM
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before i pulled the dizzy out i clearly marked 3 different spots on the dizzy and engine so that there was no confusion of how to reinstall it. i did not crank the motor or move the truck at any time. yes the dizzy went right back in place in the same motion that it came out.

the hot start problem, would i need to advance the timing or retard it? as of right now my timing is set at 28* total timing. this is what my engine performance resources suggested for timing. since i adjusted the timing to 28*tt the response of the truck has been exellent.

as for the WD-40 suggestion, i'll try that right after i go through all the manifold bolts and carb hold-down nuts.

thx for your suggestions and input!
 
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Old Apr 9, 2005 | 11:55 AM
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From: Union, Washington
Originally Posted by '70_f-100
before i pulled the dizzy out i clearly marked 3 different spots on the dizzy and engine so that there was no confusion of how to reinstall it. i did not crank the motor or move the truck at any time. yes the dizzy went right back in place in the same motion that it came out.

the hot start problem, would i need to advance the timing or retard it? as of right now my timing is set at 28* total timing. this is what my engine performance resources suggested for timing. since i adjusted the timing to 28*tt the response of the truck has been exellent.

as for the WD-40 suggestion, i'll try that right after i go through all the manifold bolts and carb hold-down nuts.

thx for your suggestions and input!
If you didn't recheck the timing with a lite after your reinstall of the dist it could be off as much as 10 degrees and you would still think you were on the marks. The PVC valve is easy to check, pop in out of the valve cover and put your finger over it. IMHO 28 degrees total is retarded for optimum preformance and mileage, 30 to 32 would be better. An overheated motor from retarded timing (28-10=18) will cause the slow crank on two levels. #1 Hot starter motor will require more amps and still not crank properly. #2 the hot spots in the combustion chambers will cause preignition and kick back, resulting in slow crank.
 
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Old Apr 9, 2005 | 03:09 PM
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when i reinsatalled it i hand cranked themotor untill it was TDC then installed it according to my marks i made. next i used an inductive timing lite for the final adjustments.

what do you mean, just time it like normal or is there some speacial dizzy timing i should have done to reinstall the dizzy?

i also found my vacuum leak. it's at the carb spacer plate. the carb rebuilt kit also came w/new spacer gaskets (2) that i replaced. when i tried the WD-40 trick and hit the spacer the engine noticably gained rpm's. next problem nobody sells just a 2bbl spacer and ford discontinued it in early 2000. i have called many parts stores and found nothing. i do not want to buy a used one, do to my recent expierence w/a rebuilt motorcraft from holley.

is there any quick fix i can do to just make it 90 miles back home, or just fix it later and risk it?

p.s. what does the little green square next to how many times i've posted represent?
 
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Old Apr 9, 2005 | 03:55 PM
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From: Union, Washington
Get a couple of thicker gaskets and stack them to get home. Back in the dark ages Ford had a coolant heated aluminum spacer for the 2V's (and 4V's for than matter). I never used the coolant part, even cut off the hose nipples, but they were good spacers and with the inside open to the outside air they seemed to hold down the heat soak.
 
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Old Apr 9, 2005 | 05:39 PM
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From: Lacey, WA
Hi,

Go to the nearest auto parts store and buy a sheet of gasket material. Trace out the pattern of the carb and cut it out. Will work like a champ!

Lee
 
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Old Apr 9, 2005 | 06:15 PM
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'70_f-100's Avatar
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From: prescott valley, arizona
i found the gasket that goes manifold to spacer that is about 1/4in thick. w/a little modifing to my carb it all bolted up and nomore leaks! it was a simple overlooked part

thanks for your help and advice!
 
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