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#1
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Point Gap on '72 4.5 (280SE)
Does anybody know what it should be? I have no idea. I blew something in the exhaust system today after it backfired on me. I went to the junkyard Monday and got an ignition box, got it running Tuesday after about 4 years of sitting. Put the lower A-Arm on today. Drove it around my driveway a little and parked it back where it was and was revving it when I let off the gas and it backfired... blowing something out. I messed with them to get it started (Luckily my guess did get it running) but as for what it should be, does anyone know? TIA.
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#2
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The ballpark figure for dwell is the thickness of a match book cover. The correct setting is whatever gets you the right dwell reading.
Remember, once you change the dwell, you have to re-time the engine. For this car, that means plugging the vacuum lines and revving to 4500 rpm and setting the timing to the right spec. I don't have either measurement here at my fingertips. While you are waiting... The fuel delivery system in this car is VERY sensetive to vacuum leaks. Check the archives for 4.5, 3.5, 350, 450, EFI, D-jet and/or D-jetronic references. Also, check and set the valve clearances. -CTH |
#3
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I have no idea how to do ANY of that. Heh. I assume to adjust valve clearance I take the covers off and turn the screws/nuts whatever until it's to what the manual says?
As for the point gap, I was hoping you just adjust them to a certian gap when they're fully opened. Guess I should take it to the shop then. I dont have a timing light. |
#4
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Tom:
Unless you drained and cleaned the tank, I suspect your backfire was from the poor combustion of the dead gas you had sitting in the tank. You may want to drain it all out, put in around a quarter tank of fresh premium, then add a whole bottle of injector cleaner (Redline is best, else Shell), then jumper the fuel pump relay and let it run a while. Drive it all out, then fill up with fresh fuel. If it started and ran reasonably well, I'd not suspect the ignition circuit to be bad, and the point gap will not change with sitting. The points might corrode, but that is a different issue. If it ran rough and shook a lot, could be. If you don't have a dwell meter and timing light, let someone else tune it up. Dwell is 32 degrees ( used points), 30 degrees (new points), timing is 5 degrees ATDC with vacuum on the retard diaphram (check this!!!), 7 degress BEFORE TDC with the diaphram disconnected and plugged (engine side) and engine at cranking speed. Make sure the idle is correct at 800 rpm. If you cannot set it with the very large idle speed screw on the intake manifold (next to the hose from the driver's side valve cover) you have a vacuum leak that must be fixed. Most likely causes are dead injector seals, broken vacuum lines, or dead seals between the manifold halves. Peter
__________________
1972 220D ?? miles 1988 300E 200,012 1987 300D Turbo killed 9/25/07, 275,000 miles 1985 Volvo 740 GLE Turobodiesel 218,000 1972 280 SE 4.5 165, 000 - It runs! |
#5
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If this car is your daily driver and need it to get to work and all that, take it to a shop.
If you can aford the time and energy and want to learn how to care and feed this wonderful road machine, then invest in 8 tools... - A timing light - A digital tach/dwell meter - A special crows foot needed to adjust the valve rocker studs (your description is essentially correct; you just need a wierd wrench to do the turning). - A set of metric flare wrenches (10mm, 12mm, 14mm, 17mm, 19mm, 22mm) Though you only need the 19mm for the jobs listed. - Longest 1/2" drive breaker bar you can find. - 28mm (or 1-1/8") socket (which will be 1/2" drive). - Set of metric feeler gauges. - The 280SE 4.5 engine and body service manuals I am presuming that you already have - A set of 3/8 drive, 6 point, metric sockets (both short and deep). - A set of 3/8 drive extension rods & a universal. - Suitable 3/8 drive rachet handle. - A set of metric combination wrenches from 7mm up to 22mm (specifically the 7, 8, 10, 12, 13, 14, 15, 17, 19, 22mm). We'll walk you through the various tasks. -CTH |
#6
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Peter, you're right, I forgot to mention setting the idle speed after the timing.
I didn't want to scare him with the issues about leaking vacuum. I hate it when I get little puddles of vacuum all over the place. If you do go to someplace to have it fixed, and they want to replace fuel injection parts, ask us first before you OK the work. Sometimes the shop knows what it is doing, and some times they can be making a mistake (and sometimes it's an innocent one). -CTH |
#7
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Oh, forgot to say the tank had 100% fresh 93 octane in it
__________________
Current: 2021 Charger Scat Pack Widebody "Sinabee" 2018 Durango R/T Previous: 1972 280SE 4.5 2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi" 1999 Chrysler 300M - RIP @ 221k |
#8
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A breaker bar is just a long handle for a socket. Think of it as "break your knuckles" if you grip it tight and use it on a stubborn nut. But more importantly, "break free a stubborn nut". Lastly, when used to over tighten a nut or bolt, you will break the bolt if you over tighten it. That's why things have torque specifications.
Most of the tools on your shopping list can be purchased from ebay. BUT, be sure to find out the retail price of things (walk into a sears) so that you don't pay more than the fair market price. -CTH PS. Not not brake your knuckles, either pull towards you with your hand holding the wrench with a closed fist on the tool. If you have to push, then, push away from you with an open palm. |
#9
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(Weird, my post was entered as if it were later in the day. Hmm)
Yeah, I just use a pipe. I have a 3' long pipe I put over my wrench. I used it to take the lugs off the pass wheel when I replaced the A-Arm. Oh, by the way, does anyone know the best way to remove broken lug bolts from the hub?
__________________
Current: 2021 Charger Scat Pack Widebody "Sinabee" 2018 Durango R/T Previous: 1972 280SE 4.5 2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi" 1999 Chrysler 300M - RIP @ 221k |
#10
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I have all the metric sockets (though not deep ones) as well as standard sizes in a kit with the large wrench (not 3/8, what is it, 1/2?). Anyway, it's kinda a project car and I just want to work on it and have fun.
I did drive it a little today, and it's smoking heavily (but I cant blame it, a lot of stuff is on the headers). I suppose tomorrow I'll clean it off and pop the valve covers off (the one on the drivers side is a PITA because of the power steering hoses). I dont have any feeler gauges. I have wanted a set for well over 5 years now. I need to do any work relatively soon as Tuesday I'm moving back in to school. The next time I'll be able to work on it is during intersession. I have adjusted the idle with that screw before but have not touched it at all as it idles (to me) perfectly fine and does not stall at all. I have no service manuals for it. The only manuals I have are owners, warranty, emissions, and parts. I also have MOST of the original tools. If I may, what is a breaker bar, and what would I need the 1+1/8" socket (which I do have) for? |
#11
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Tom:
what color smoke and where does it come from? Blue smoke out the exhaust is oil smoke. probably from bad valve guide seals and sitting so long. Black smoke out the exhaust is probably a bad MAP sensor -- this is sorta expensive, but vital, as if it is bad the mixture will be way off. Peter
__________________
1972 220D ?? miles 1988 300E 200,012 1987 300D Turbo killed 9/25/07, 275,000 miles 1985 Volvo 740 GLE Turobodiesel 218,000 1972 280 SE 4.5 165, 000 - It runs! |
#12
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White smoke off the headers
There's stuff on them (Including a lot of that foam from the hood). I think that's it, although the valve covers may be leaking.
__________________
Current: 2021 Charger Scat Pack Widebody "Sinabee" 2018 Durango R/T Previous: 1972 280SE 4.5 2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi" 1999 Chrysler 300M - RIP @ 221k |
#13
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Most likely cracked valve cover gaskets, cheap and easy to replace. If you don't have smoke out the tailpipe, just replace the valve cover gaskets (details if you need them, they fit over the edge of the cover, no sealant), should fix the trouble. They have surely died from old age.
Get some injector cleaner in the fuel, the injectors are most likely sticky from the residue from old fuel. A tank of two of good gas will fix you up, if not you may need new injectors. You will be amazed by this car when you get it running, they have tremendous power and drive very nicely! Peter
__________________
1972 220D ?? miles 1988 300E 200,012 1987 300D Turbo killed 9/25/07, 275,000 miles 1985 Volvo 740 GLE Turobodiesel 218,000 1972 280 SE 4.5 165, 000 - It runs! |
#14
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Heh, the injectors probably have rust in them.
The metal fuel lines rusted and have holes in them. I replaced one section and took it for a test drive, only to return and see it was leaking in another spot But I can still remember my dad doing well over 100MPH in it. Sure, I do that in my Jeep and parents Intrepid, but not with a muscular V8 Where would I FIND new valve cover gaskets? They are what appears to be a polymer (or EXTREMELY hardened rubber that isnt cracked). I think that they arent on tight enough (they only have 4 bolts per cover, which I find odd). The only smoke coming from the exhaust is carbon when I lay on the gas pedal (it left a pair of black circles on the container I had behind it). It always did that to my recollection (it isnt heavy, just a small puff). I think the mixture is too rich, how do I lean it out?
__________________
Current: 2021 Charger Scat Pack Widebody "Sinabee" 2018 Durango R/T Previous: 1972 280SE 4.5 2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi" 1999 Chrysler 300M - RIP @ 221k |
#15
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Austin:
If the fuel rail is rusted out, plan on replacing rails and injectors eventually -- you may get lucky and flush it all out, but I'd guess not. The valve cover gaskets, if hard, are shot. They are soft rubber molded in a U shape, fit over the edge of the valve cover. The cover is machined flat, so it doesn't take much pressure to seal it properly. Those four bolts, gently tightened, will seal them up tight. Yours are probably cracked across the sealing surface, and oil just runs through. They are available from MB, or any place that sells MB parts -- they haven't changed, that I know of, since 1970. Should only be about $15 each, but that is a guess. They are also probably available here on FastLane, too. As to the mixture, you can adjust it on the control box, but I'd get all the rubber bits up to date first, since vacuum leaks will drive you nuts on this car. There are rubber seals on the injectors and between the manifold halves, and there are several vac lines that need to be checked for leaks before you attempt to set idle speed or mixture. Once that is up to snuff, you will need to have someone who knows what they are doing with a CO tester to help you set the mixture. Bottom line, if it runs, doesn't leak fuel, and gets at least 12 mpg, you are in the ball park. Call around to junk yards for the fuel rail, it will be much cheaper (and I may have a spare in a couple weeks, anyway!). Injectors are about $30 each, I think, but I could be way low. They can be cleaned -- if they have crud in them they tend to drip fuel, making you run rich at idle. Peter
__________________
1972 220D ?? miles 1988 300E 200,012 1987 300D Turbo killed 9/25/07, 275,000 miles 1985 Volvo 740 GLE Turobodiesel 218,000 1972 280 SE 4.5 165, 000 - It runs! |
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