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heinz57
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Dec 16, 2010, 4:41 PM
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timing problem
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1981 ford f350 300 in line 6. Bolt that attaches pulley to cam shaft fell out lost belts and ended up with extreme overheating. Replaced bolt, belts, coolant, and oil. Today the engine jumped timing, missing and backfiring. Pulled #1 spark plug and distributor rotor cap is aimed at it. Dropped a wood dowel into cylinder and piston is at bottom when it should be at top. I don't believe this engine has a timing chain, could be wrong, so I'am guessing the bottom distributor gear sheared or some other problem. Could overheating cause the distributor to go bad?
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re-tired
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Dec 16, 2010, 7:55 PM
Post #2 of 40
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Re: timing problem
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How do you know that eng has jumped time ? Have you done a compression test . A blown head gasket from over heating is a possible cause of rough running. To check the valve timing you neeed to pull the valve cover. Turn eng over by hand .When the piston is at its TDC AND both valves are closed (WATCH ROCKERS FOR #1, BOTH WILL BE LOOSE). Now rotor should be at #1 plug wire.
LIFE'S SHORT GO FISH
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heinz57
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Dec 17, 2010, 1:33 PM
Post #3 of 40
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Re: timing problem
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This is a bit more than rough running. When in gear it bucks and backfires and barely crawls. I know when replacing a distributor you aim rotor cap to number 1 cylinder with the piston at TDC. I currently have the rotor aimed at number one cylinder with the distributor still bolted down after shutting the engine off and the piston is at bottom of the cylinder. Because of the backfiring I had guessed a timing issue. There is no coolant in the oil, although coolant is down alittle and it has been running hotter than normal. Plugs are burning normal and there is no blue smoke or condensation at the tail pipe. Next I will do a compression check. Thanks for the response
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Jeff Norfolk
Enthusiast
Dec 17, 2010, 1:39 PM
Post #4 of 40
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Re: timing problem
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I would still be looking at a head gasket issue or the like. Just because there is no visible coolant in the oil doesn't mean there isn't a problem. Coolant low and running hotter then normal after a overheat issue is troublesome. Especially with the performance problems you are having. You can borrow a cooling system exhaust gas checker from your local auto parts store. This will tell the tail.
Jeff
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Sidom
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Dec 17, 2010, 2:06 PM
Post #5 of 40
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Re: timing problem
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There is a lot of unknown variables here. When he says the pulley to the cam shaft I'm assuming he meant the crank pulley (& maybe balancer??) since the cam has no pulley.
He is checking the timing backwards but even so with the rotor pointing at #1 the piston shouldn't be at BDC which I believe he is saying what is happening. I would double check it the normal way. Pull #1 plug, bring it up on compression then put the timing mark on zero by hand, pull the cap & see where the rotor is point. ( RTs way is more accurate and a spun balancer can give you bad test results but it's a little quicker, any questions at all & the v/c cover would have to come off) From what he is say it sounds like it's going to be 90° off.
This being the case since it has no chain and is gear to gear I would 1st pull the dist & check the gear. I don't think I've ever seen gears jump but then again I don't know what came apart on the bottom end, how long it was driven before this problem popped up but it is way easier to R&R a dist than pull a timing cover......
Plus throw in the fact we are talking about a 30 year old 1 ton truck with a straight 6 & who knows how many miles........I think at this point ANYTHING is possible but I would start with eliminating the easy stuff 1st......
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heinz57
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Dec 17, 2010, 2:35 PM
Post #6 of 40
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Re: timing problem
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Engine is a NAPA rebuilt 3 years old and aprox 25,000 miles or so. Until the pulley problem and the over heating the engine has run great needing only about 1/2 quart oil between changes. Will check on the cooling system exhaust checker and bring #1 to TDC and check rotor position if its still off I pull the valve cover and check there. Strange that the engine idles and I can rev it without misses but when in gear it boggs down and backfires??? Appreciate your responses.
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Sidom
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Dec 17, 2010, 2:50 PM
Post #7 of 40
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Re: timing problem
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Ok, I guess I missed the idling part earlier.
I don't know how it runs but if it runs good at idle then the gear hasn't sheared & the timing gears haven't jumped, those would make it run bad all the time....
I would put a vacuum gauge on it and check vacuum at idle, high rpm and under load (in gear) if the vacuum drops close to zero you might have a restricted exhaust system. The backpressure would need to checked or a good backyard trick would be to take the pipe off the exhaust manifold, fire it up and see how it runs in gear, if it runs good then you have an exhaust problem....
Now that you mention this problem I remember years ago I had on old Bronco 351? I had to change the dist in. I put a reman in it and it would idle great & run like crap in gear...... I didn't test anything just got another one & it ran great. I would check the vacuum & back pressure 1st. The only real way you will be able to test the dist or module would be with a scope......
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heinz57
User
Dec 18, 2010, 3:02 PM
Post #8 of 40
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Re: timing problem
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Did the compression check and here's what I have:
#1 65
#2 120
#3 90
#4 120
#5 120
#6 120
Real problem with #1 would this be rings, valves, or gasket? Will I still need to do cooling system exhaust check?
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Jeff Norfolk
Enthusiast
Dec 18, 2010, 4:30 PM
Post #9 of 40
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Re: timing problem
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So is #3. You are gonna want to go ahead and pull that valve cover off. Turn the motor over till #1 cylinder is at TDC and see if the valves are closed or not. If they are then take the valve core out of your compression tester and pump some shop air and see where it comes out. If it comes out the cooling system - head gasket or water jacket proble. Out the oil cap - porbable ring. Out the intake or exhaust - valve problem. Good luck
Jeff
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heinz57
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Dec 18, 2010, 5:43 PM
Post #11 of 40
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Re: timing problem
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Thanks for the quick reply.
Valve is not removeable on my guage. Will have to get leak down tester. Harbor Frieght has one for less than $40.00. For got to mention #3 had burned up a new plug in about a week ???
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heinz57
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Dec 19, 2010, 5:28 PM
Post #12 of 40
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Re: timing problem
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I did get the schade valve out, just a few rough threads. When I do the air do I do all cylinders or just #1? When I took the valve cover off I found loose parts on the head!! Is there a way to send photos. I will try to describe them but they are nothing I recognize as parts of valves, rocker arm or anything related to the head. Washer, spring and solid machines piece shaped like a rubber valve stem tire rim. I did push air into #1 and get nothing. Thanks for your help.
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Hammer Time
Ultimate Carjunky
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Dec 19, 2010, 5:54 PM
Post #13 of 40
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Re: timing problem
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WOW, If you have a loose valve spring in there, then you have big time problems. That would mean the valve retainer came out of the valve and the valve would have dropped into the piston................. engine toast. I would have expected banging noises in the engine though.
The best way to post pictures here is to use an image hosting sight and they will supply a link to post here that makes the image show up here.
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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.
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re-tired
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Dec 19, 2010, 9:43 PM
Post #15 of 40
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Re: timing problem
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Looks like there's enough faults with this one for everyone to have a piece of the pie. Sounds like we are talking eng if it has indeed gulped a valve. 
LIFE'S SHORT GO FISH
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heinz57
User
Dec 20, 2010, 8:30 AM
Post #16 of 40
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Re: timing problem
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I have never seen the guts of a PCV valve before, now I have. Should of guessed that from their location on the head. Duh! Ford recommend idleing the engine for 30 minutes before doing a compression check which I did and it idled okay with a miss but I found a burnt plug in #3 that may have caused this. I also cranked the engine with the plugs out and could see no evidence of coolant coming out the cylinders. So far, no antifreeze in oil. no bubbling in the radiator ,no vapor from tail pipe and nothing from air check on #1 cylinder. Do I do the air check on all cylinders or just #1? I know this has been a drawn out issue and I appreciate your help and patience.
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Jeff Norfolk
Enthusiast
Dec 20, 2010, 9:44 AM
Post #17 of 40
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Re: timing problem
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Air check is just for the low compression cylinders. But at this point with the loose parts (what ever they are) under the valve cover, that is the place to start. If you have a broken or loose spring then that is your compression problem. Assuming they are from the affected cylinders.
Jeff
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heinz57
User
Dec 20, 2010, 12:17 PM
Post #18 of 40
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Re: timing problem
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I looked up a cutaway of a PCV valve and the loose parts I found on the head are consistent with it. A pintle(loose part I described as a miniture wheel/rim air valve but machined steel), a small spring, a washer and they were straight down from the PVC hole in the valve cover. I have visually checked the valve springs, push rods and the rocker arms and see nothing obivously wrong. The air check of the 2 suspect cylinders reveals nothing. No radiator bubbles, air coming back thru throttle or exhaust. When I bring #1 cylinder to TDC the rotor does point 20-30 degrees away from it. Yet I get a fairly good idle?? Guess I'ma at a crossroad here. What should be my next move?
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Jeff Norfolk
Enthusiast
Dec 20, 2010, 12:51 PM
Post #19 of 40
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Re: timing problem
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I would pull the distributor and take a look. At the very least it needs to be timed correct. Probably something else wrong with it though. Put a new PCV in and restabe the distributor if all is ok.
Jeff
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heinz57
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Dec 20, 2010, 2:48 PM
Post #20 of 40
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Re: timing problem
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That's what I will do. Maybe something will pop up. Will not have fixed anything except the timing. I will let you know what happens. Once again thanks for your help
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heinz57
User
Dec 23, 2010, 6:10 PM
Post #21 of 40
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Re: timing problem
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Got it back togather today and drove it for 15- 20 minutes. Engine ran ok, but still running hotter than normal. Checked coolant when done with short run, still full. Is it possible with the overheating that I ruined the sensor? Need to put more miles on it but will not be able to until after holidays. Will post results after I put more miles on it. Thanks again
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Tom Greenleaf
Ultimate Carjunky
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Dec 23, 2010, 7:09 PM
Post #22 of 40
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Re: timing problem
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"running ok but hotter than normal" ??
Does that mean it is over the range into hot or just showing a higher temp? Run heater and feel the heat or even put a wired remote in a duct - very tell tale of what's really happening. If heater goes cold on you and shows running hot it's probably boiling and vapor even hot doesn't blow heat,
T
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heinz57
User
Dec 26, 2010, 1:04 PM
Post #23 of 40
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Re: timing problem
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Just showing higher temp, heater blows hot air. No drop in coolant after 30-40 minute drive. Engine seems to idle ok, but when I put it in gear the engine acts like it's missing but once I accelerate it runs fine. I think next is a leak down test. Still feel have a valve related problem.
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heinz57
User
Mar 13, 2011, 6:27 PM
Post #24 of 40
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Re: timing problem
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Replaced distributor and now cannot get it started. Compression check all cylinders within 10%. Checked valves, rockers, push rods ok. #1 cylinder at TDC rotor pointed at #1. Cranks but no start. Have fuel & spark?? Moved Distributor one tooth either side of TDC. Some backfire but it will not start??
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re-tired
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Mar 14, 2011, 9:23 AM
Post #25 of 40
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Re: timing problem
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Are you making sure when setting #1 cylinder to TDC that you are on TDC COMPRESSION STROKE ?
LIFE'S SHORT GO FISH
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