| Timing Chain Replacement [message #213606] |
Sun, 07 July 2013 11:52  |
winter
Messages: 247
Registered: September 2007
Location: MPLS MN
Karma: 0
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Over the past 10 years, the fuel mileage went from around 9 or 10 down to about 7 or so last fall. I figured either my driving habits were getting worse or something was wearing out. A couple years ago, I replaced the cracked intake manifold with an Edelbrock aluminum intake and I also rebuilt the carb and installed an electric choke. The choke never seemed to be in proper adjustment and the GMC was really cold blooded.
I figured that I did a poor job at rebuilding the carb and the choke should be replaced with one of those electric thermostat chokes. The GMC has about 120 000 on the clock so I decided this spring to replace the timing chain and water pump. The job went pretty well and Jim K was able to help me out after I twisted off my fuel line. The chain was really loose. It probably would have jumped a tooth this year had I not changed it.
Now that I have it back on the road, it runs completely different. The engine doesn't labor holding 60 MPH and it cruises easily. It fires right up when cold and it doesn't sputter and die when I put it in gear. I should have changed the timing set back when I first saw a decrease in mileage. Now I know better.
I can't wait to take it on a longer trip to see what the mileage is now.
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| Re: Timing Chain Replacement [message #213650 is a reply to message #213606] |
Sun, 07 July 2013 21:28  |
winter
Messages: 247
Registered: September 2007
Location: MPLS MN
Karma: 0
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I put a 4 cylinder diesel in an Rx7 and used it as my daily driver for a few years. I put 50k miles on before the driver seat area seperated from the rest of the car. I guess not having any vacuum assist on the brakes put too much stress on the floor.
The car pulled about 48 MPG on #2 and about 39 in winter on #1 with 4:10 gears. With 3:21 gears the fuel consumption should have been reduced by 50%.
Jerrod Winter
1977 Palm Beach
Green Jelly Bean
Twin Cities, Minnesota
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| Re: Timing Chain Replacement [message #213691 is a reply to message #213606] |
Mon, 08 July 2013 10:52 |
lqqkatjon
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
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that is impressive.
that is very interesting what you said about the timing chain.
I have no history of my coach, but it seems to run good, with the exception of the fuel mileage I would hope to be a little better.
I am doing better with tune up now, then I have ever, but still hoping for a few more MPG. I am still targeting the 8-10. The one trip this year I tracked, where i was not towing, was 7.
I have just over 70K on the odometer. and I was planning on doing a timing chain soon, but I have plenty of projects going on, I was thinking either next spring, or the spring after. but if I could gain a MPG. I would be tempted to do it sooner.
anybody else have the same experience?
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
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| Re: Timing Chain Replacement [message #216181 is a reply to message #213606] |
Mon, 29 July 2013 20:45 |
winter
Messages: 247
Registered: September 2007
Location: MPLS MN
Karma: 0
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Senior Member |
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Made a trip to north eastern wisconsin last week. About 750 miles total round trip. I averaged about 10.5 MPG running 65 to 70. I think the new timing chain helped.
I also have heard that the stock timing sets are slightly retarded while the new ones are advanced. That could also be part of the difference.
Now I need to fix the electrical problem, but thats a different discussion.
Jerrod Winter
1977 Palm Beach
Green Jelly Bean
Twin Cities, Minnesota
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| Re: Timing Chain Replacement [message #216197 is a reply to message #213606] |
Mon, 29 July 2013 21:54 |
winter
Messages: 247
Registered: September 2007
Location: MPLS MN
Karma: 0
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Senior Member |
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I thought i did that 9 years ago but perhaps I just thought i did. will do now.
Jerrod Winter
1977 Palm Beach
Green Jelly Bean
Twin Cities, Minnesota
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