timing chain question...
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New User
Joined: Dec 2003
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timing chain question...
i have a 79 bronco with a 351m, the prevous owner bought the bronco with a timing chain that was basically shot so he tore it down and replaced the gears and chain and all the pumps and gaskits that it takes to get to it etc... now after he put it back together its runs pretty poorly as i got it form him and from what i can tell the timing is off due to it does run.... but wont stay running unless i keep my foot on the pedal..... it has no pwoer whatso ever it has a slight valve tap like it would if the timing were off......... the big question the old owner and i want to know is IF HE DIDNT LINE UP THE GEARS CHAIN ETC WOULD IT RUN OR DID HE DO IT RIGHT AND THE TIMING IS JUST OFF VIA THE DISTRIBUTOR? FROM WHAT I HEAR IF HE DIDNT DO THE CHAIN AND STUFF RIGHT THE MOTOR WOULD NOT RUN AT ALL . i just dont want to tear all that crap of for nothing
Senior User
Joined: Apr 2004
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From: I live in Calif. near S.F
ASK the guy that put the t/chain in, ask him if the engine was on number one TDC, #1 piston up at the top ,and if he had the two dots on the gears lined up, if he did make sure the dist. was installed properly, rotor at #1 wire, if he did then you might have to check for bent valves ? when its running dose it pop out the carb. when you give it the gas?
Logistics Pro
Joined: Jan 2002
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From: suburban atlanta
Take a little time, and mark the crank pulley at tdc, +90 +180 +270. Pull rocker cover, and watch the valves for #1. at about 180 before tdc, the intake should just start to close, and should stay closed up to tdc, and after...for about 180. on the next upstroke, the exhaust should be opening.. Hope you get the picture.
If you don't like to do all that, you can at least get an idea if the timing is off by watching the rotor as you slowly crank the engine up to TDC.
Make sure the plug wires are on in the proper firing order. More than one of us has been bit by being so sure that everything was right... and not doing the check
tom
If you don't like to do all that, you can at least get an idea if the timing is off by watching the rotor as you slowly crank the engine up to TDC.
Make sure the plug wires are on in the proper firing order. More than one of us has been bit by being so sure that everything was right... and not doing the check
tom
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the guy dont remember.. the truck does not backfire out the pipe or the carb its seems to run fine except it stalls as soon as i take my foot off the gas pedal, and when i put it in gear it takes forever to get going it has no power at all, and just doent sound right but it seems to want to go so this weekend im going to try and move the distributor.... so after i get the 1 piston a TDC ill pop the assembly up and move it question now is where should i set it back in at?
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Joined: Mar 2004
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The only way you can truely know that a cam is timed right is with a degree wheel. I have seen "properly installed" cams that were off 2-3 degrees on wheel. Sometimes, lineing the dots up doesnt work. Dont ask me why, because I do not know. Most serious engine builders would not even casually consider putting a cam in without degreeing it.
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Joined: Apr 2004
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From: I live in Calif. near S.F
This is a Quick check, loosen the dist. so you can rotate it start your engine rotate your dist. clockwise 1/4" at a time , snug it so not to move and drive it,unless you have a timing light, do it see if it run better .
