Question on a 351W.
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Joined: Nov 2004
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From: Asheville, NC
Question on a 351W.
My 1983 351W 2bbl is running very poorly recently.
Several co-horts here have suggest the timing chain, since the truck has 188K on it now.
Do any of you have any experience at how the motor runs after it jumps time?
This one gets incredibly weak as you let it speed up. It acts like it wants to backfire, but never does.
This truck used to have DS-III ignition, but now has DS-II. It was acting up before the ignition changeout.
Also, when it is warmed up, but not hot, the starter will not turn the motor over until I let it sit for 5-10 minutes, sometimes. Has a brand new starter.
Drove it to Atlanta GA a few weeks ago. I drove it like I had an unbroken rotton egg under the gas pedal... very gently, and still only got about 8 mpg with no load. On the return trip, it still got 8 mpg with a heavy load in the back.
Any ideas? This is got me confused thoroughly.
Oh yeah, Carb has been checked out, along with fuel system. It's all good.
Several co-horts here have suggest the timing chain, since the truck has 188K on it now.
Do any of you have any experience at how the motor runs after it jumps time?
This one gets incredibly weak as you let it speed up. It acts like it wants to backfire, but never does.
This truck used to have DS-III ignition, but now has DS-II. It was acting up before the ignition changeout.
Also, when it is warmed up, but not hot, the starter will not turn the motor over until I let it sit for 5-10 minutes, sometimes. Has a brand new starter.
Drove it to Atlanta GA a few weeks ago. I drove it like I had an unbroken rotton egg under the gas pedal... very gently, and still only got about 8 mpg with no load. On the return trip, it still got 8 mpg with a heavy load in the back.
Any ideas? This is got me confused thoroughly.
Oh yeah, Carb has been checked out, along with fuel system. It's all good.
Cargo Master
Joined: May 2007
Posts: 2,071
Likes: 36
From: British Columbia
"Do any of you have any experience at how the motor runs after it jumps time?"
Yes, it runs like crap, with low power and very hard to start because the spark is so far advanced. Check the ignition timing to see if it is way out of specs, which would also be evidence of timing chain jumping.
However these symptoms occur suddenly, right when the chain jumps a tooth. So if this is what happened then you should have noticed the problem occur all of a sudden.
Yes, it runs like crap, with low power and very hard to start because the spark is so far advanced. Check the ignition timing to see if it is way out of specs, which would also be evidence of timing chain jumping.
However these symptoms occur suddenly, right when the chain jumps a tooth. So if this is what happened then you should have noticed the problem occur all of a sudden.
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Posting Guru
Joined: Nov 2004
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From: Asheville, NC
I dread pulling the timing chain cover. I had surgery on my stomach area a few years ago, and I hate having to lay over the front of the truck to work on it.
The truck is worth the repair effort to me. It's been a dependable almost-daily user, but has run like crud for about 4 years. I know, 4 years, but when you have major surgery, it takes a long time to be able to handle having pressure of any kind against the scars.
Thanks for the comment. Will update this as work progresses.
Bruce
The truck is worth the repair effort to me. It's been a dependable almost-daily user, but has run like crud for about 4 years. I know, 4 years, but when you have major surgery, it takes a long time to be able to handle having pressure of any kind against the scars.
Thanks for the comment. Will update this as work progresses.
Bruce
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how old is the starter Ive bought brand new ones before with the old starter being better than the new when i buy a new starter now their is a guy close to
the house that works on starters and alternators and stuff like that i take it over to him and have him check it out you would be surprised how many of them were missin parts hope this helps
the house that works on starters and alternators and stuff like that i take it over to him and have him check it out you would be surprised how many of them were missin parts hope this helps
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Posting Guru
Joined: Nov 2004
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From: Asheville, NC
how old is the starter Ive bought brand new ones before with the old starter being better than the new when i buy a new starter now their is a guy close to
the house that works on starters and alternators and stuff like that i take it over to him and have him check it out you would be surprised how many of them were missin parts hope this helps
the house that works on starters and alternators and stuff like that i take it over to him and have him check it out you would be surprised how many of them were missin parts hope this helps
The starter is a new old-stock Motorcraft. The OEM starter got new brushes when I bought the truck, and always gave trouble when hot. Bought the new starter. Same problems. Replaced the cable from the solenoid to the starter with a heavy custom cable that a friend made up for me. No changes.
Starter turns fast when the motor is cold. It's not the starter causing these problems.
Last edited by Holmesuser01; Aug 1, 2011 at 10:22 AM. Reason: clarifications.
FTE Legend
Joined: Jun 2006
Posts: 31,930
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From: Ottawa, Ontario
Maybe.. maybe not. To me it souds like the motor is running rich, evidence is poor milage and hard starts when warm caused by extra fuel washing oil from the cylinder walls. This could be caused by a stuck float valve in the carb for example, or the rich condition could be a result of a partially clogged exhaust system. The factory exhaust systems on these trucks are notoriously restrictive so if any portion of it remains(especially the cats) it's probably time it was replaced.
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