Power challenged 352

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Merc66
Posts: 1
Joined: March 1, 2015, 11:49 am

Power challenged 352

Post by Merc66 »

Hello all, my first post since joining and glad to find the resource.
My 66 M100 has an issue with getting going.
It's as if it was starting out in 3rd ( or higher if it had a higher gear).
Engine bogs down and I have to rev the hell out of it to get it going.
Just completed a clutch job that I think went well and it all goes fine with the truck up on 4 jack stands, clutch works fine, goes through the gears and all that.
It has the Borg Warner overdrive and for a while I thought it was stuck in OD, but it seems to struggle in reverse as well.
Then I talked to a guy who has the same problem but no OD so I am thinking something in the carburetor/vacuum system??
Any thoughts?
Thanks
Dave
64 f100
Posts: 2754
Joined: July 18, 2006, 7:23 am
Location: Carmi, Illinois, 62821

Re: Power challenged 352

Post by 64 f100 »

What gear ratio is in the rear end? Supposed to be 3.50. Also, is the engine warmed up when you have this problem? These trucks are notorious for being cold natured, until the engine is warm. This does not sound like your problem though. The overdrive transmission has a lower first gear ratio than a standard without overdrive if I remember right. However, someone may have changed out the rear gearing to try and get better mileage at one time. Or, because the overdrive had quit working. 3 speeds usually came with a 3.25 ratio and overdrive 3.50. May be I have it wrong about first gear ratio, but it is different from one to the other in the transmissions. I have an overdrive in one of mine that has a 3.25 rear end but it starts out fairly well. The overdrive is not working in it and assumed the rear end was changed to compensate for the loss of the overdrive. Otherwise, I see no reason your truck won't take off properly. No high performance engine but still should have plenty of power to take off. Wondering about the adjustment on your brakes, and if some are causing a drag on the wheels? Maybe a stuck brake cable? Otherwise, lack of power can come from leaking valves and or worn engine components.. A little history on you truck might help in getting a possible answer. Have you ran a compression check on the engine? Another thing , has the engine backfired through the carb.? If so, then you most likely have a bad economizer valve. Very common to have this happen, and the engine will then start to flood. Backfiring thru the carb does this nearly every time, especially when it is an old economizer valve. Another thing is todays gasoline, the old rubber carb parts don't do well with todays fuel. Methanol/ethanol do not work well with old rubber parts as in the carb and fuel pumps. I would start by checking compression. Any difference between cylinders of 20 lbs. or more is a sign of wear in vale leakage or rings. Vacuum advance on the distributor is another thing to check. Take the cap of the distributor and attach a fresh clean vacuum hose to the vacuum advance and suck on the hose and put your tongue over the end once you have vacuum and can see the distributor plate move. Once you have a vacuum on the hose place your tongue on the end of the hose to hold the vacuum. If it doesn't hold, then your vacuum advance is bad. The distributor is set with the vacuum advance disconnected. If you've set it with the vacuum hooked up it will affect the running of the engine, whether the vacuum advance is good or bad. This may be where your problems are, in your timing. It's hard to say setting here at the computer. Timing chain wear can also be a problem. A history of the engine and how long it sat or if it did, whether the motor is overhauled or not, if the heads have hardened seats installed , etc. etc. are all part of diagnosing your problem. Start with basics and work you way from there. I always eliminate the points when possible, with a Petronix igniter, this helps eliminate the points as a problem in a couple of different ways. First with distributor shaft play and second with dwell settings which have to do with play in the distributor. Also, I hate points , having dealt with these devils devices since the 60's .

Rich
bruceandersson
Posts: 906
Joined: August 12, 2009, 9:44 am
Location: Ohio

Re: Power challenged 352

Post by bruceandersson »

These trucks can get into some pretty funky states. Have you actually verified that what you think is first gear is actually the correct gear? If the rods are switched or the shift levers inverted, first gear may not be where you think it is. First and reverse are on one lever and 2nd and 3rd on the other.
longcabjohn
Posts: 354
Joined: January 21, 2012, 1:08 pm
Location: waverly, Tn
United States of America

Re: Power challenged 352

Post by longcabjohn »

What does this have to do with NEW MEMBER READ BEFORE JOINING?

Johnny
If restoring a ford was easy, chevy guys could do it.
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