89' 351 running roughly
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Joined: Jun 2002
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89' 351 running roughly
Hi,
My 351 is running smoothly in idle and throughout the rpm range for most of the time, and every 5 seconds (less at higher rpms) it seem as if it jumps on two cylinders and then runs smoothly again. I've alreday changed plugs, the dist. cap and finger, so what could it be. I found some piece of pipe connecting the 4th and 8th cylinder at the back, which was a bit loose drawing air there, tightened those up and still the engine knocks about and does not feel as if it has any power. Haven't done a compression test so far, so what could it be.
Supposedly the truck only has 30000 miles on it (ex-army depot truck).
Any help would be really appreciated since in Europe nobody has a clue about these trucks.
My 351 is running smoothly in idle and throughout the rpm range for most of the time, and every 5 seconds (less at higher rpms) it seem as if it jumps on two cylinders and then runs smoothly again. I've alreday changed plugs, the dist. cap and finger, so what could it be. I found some piece of pipe connecting the 4th and 8th cylinder at the back, which was a bit loose drawing air there, tightened those up and still the engine knocks about and does not feel as if it has any power. Haven't done a compression test so far, so what could it be.
Supposedly the truck only has 30000 miles on it (ex-army depot truck).
Any help would be really appreciated since in Europe nobody has a clue about these trucks.
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New User
Joined: Jun 2002
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89' 351 running roughly
Another thing I wanted to add, what would be an inexpensive way of giving the engine some mor torque and thus more power? Since I porbably will be tearing the engine apart anyways I suppose...
What tuning measures would actually make use of very high octance fuel such as 98' Octance (German 4 Star petrol)
Sorry to ask such plain stupid questions, but here in Germany nobody has a clue about these trucks...
Thanx ever so much
What tuning measures would actually make use of very high octance fuel such as 98' Octance (German 4 Star petrol)
Sorry to ask such plain stupid questions, but here in Germany nobody has a clue about these trucks...
Thanx ever so much
Postmaster
Joined: Nov 2001
Posts: 3,351
Likes: 1
From: Escondido, CA
89' 351 running roughly
Check the distributor shaft for play. Wiggle the rotor (finger) back and forth, try to pull it up, and then side ways. Could be a worn bearing or worn worm gear. Is it possible for you to check the timing on the engine? The timing might need to be reset.
The tube you are refering to is a smog cross over. Part of the emissions crap put on them.
The tube you are refering to is a smog cross over. Part of the emissions crap put on them.
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89' 351 running roughly
I've checked the timing using a timing light, seems all ok, also advances the ignition correctly at higher revs. Will try and check the distributor shaft, thanks for the hint.
That smog tube you referred to, well I welded it shut on top and ripped all the Emissions stuff out, and it seems to run better now, but still is rumbling. any ideas?
kris
That smog tube you referred to, well I welded it shut on top and ripped all the Emissions stuff out, and it seems to run better now, but still is rumbling. any ideas?
kris
