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T-Series 51 td runs rich

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bgtrn

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we are workinb on astock 51 td. has run rich, plugs foul 10 to 30 miles. we followed mr twists advive, jeff at advanced dizzy and had j curto bedo carbs. still foul within a few moinutes at udle and undrive able 20 mikes. going nutd, any ideas??? ps we ordered lean needles.
 
bgtrn said:
we are workinb on astock 51 td. has run rich, plugs foul 10 to 30 miles. we followed mr twists advive, jeff at advanced dizzy and had j curto bedo carbs. still foul within a few moinutes at udle and undrive able 20 mikes. going nutd, any ideas??? ps we ordered lean needles.
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bgtrn - Your 51 TD engine should have the early head that uses the short reach spark plugs. I have to wonder if you have a replacement head that requires the long reach plugs. If that is the situation, you should be using the long reach plugs (i don't have the number on the plugs that should be used. You can check if the head should be using the short reach or long reach plugs by removing one of the plugs and using a piece of wire with one end bent over to produce a hook on the end. Stick the end of the wire in the spark plug hole until you can get the hooked end far enough to catch the hook inside the end of the spark plug hole. Mark the wire at the top of the threads and check the length of the threaded portion of the plug that is being used against the mark on the wire,
Cheers - Dave
 
bgtrn welcome to the forum ! There are , believe it or not , many things that can cause the problem you have and you are only giving enough information to make a guess. The spark plugs are fouled ? I'm reading that they are wet with fuel right? Or does it just start to miss and you are assuming the plugs are fouled? If they are wet with fuel and you think you are supplying more fuel to the engine than it can burn , check that you have the original fuel pump or one that puts out no more than 2-3 psi ( excess pressure will raise the fuel level in the jet and make it impossible to lean the mixture out though not necessarily overflow out the drain pipe on the top of the float bowl). Verify this by pinching off the fuel supply line while its running and see if it starts to run better when you run it low on fuel.
 
Hello and thanks, We are using long reach plugs, carbs were just rebuilt, dizzy plate, points, cond, red rotor all new, lucas sports coil[tested on multi meter and ok], spark from coil is white/blue, as well as at plug wire tips, dizzy has ground wire, no tracking in cap, pump psi is 1.5 to 2. Timing is advanced to 6 degrees. We have black smoke and black plugs. Plugs foul within minutes after start without choke and idled a 2000 rpm. Using 91 octane, ethanol free gas. Car has done this for 10 years. My buddy and I went through the carbs and dizzy, and had all problems rectified, which no "MG expert" has done in 10 years. So he enlisted my help and we had all problems corrected and problem persists. Engine was rebuilt several years ago and problem remained. Compression is 128, hot, all 4 cyl. Does not burn oil. Thanks....PS. My spelling improved a bit, with my glasses on!
 
Try leaning the mixture and see what happens. Lift the piston with a fine screwdriver a little bit and see what happens to the idle.
 
Take the carbs off again and pay attention to the throttle discs ( they should close tightly ) and the jet assembly. Its critical that the outside of the jet is perfectly smooth and free of any burr or scratches so that the 4 small cork seals keep fuel inside of the jet so the needle can meter fuel properly.
 
the problem has been resolved and a hidden one emerges. After finding many defects,problems, doing rebyilds etc and tons of elcome advice, nothing worked. So, I ordered a set of lean needles for the TD. No more black smoke, able to adjust to lean and then to correct setting. plugs 1,2,3 like new after drive and idle but.... we got a light grey smoke and a miss. Plug 4 was b;ack and wet and did not smell from gas. We redid compresiion on all 4 and got same 128 to 130, added oil and jumped to 155 to 165! Appears rings bad after 5,000 miles, probably from rich condition diluting oil, or bad rebuild or both. Wpll do leak down to check valves and have head done until money appears for full rebuild. Thanks to all
 
On the one hand, glad you found the issue. On the other hand, bummer about the ring problem!
 
Years ago, we use to put in "oil Plugs" to burn off oil. Cannot find them anymore. Cheap temporary solution. so much has been spent.
 
bgtrn said:
Years ago, we use to put in "oil Plugs" to burn off oil. Cannot find them anymore. Cheap temporary solution. so much has been spent.
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I remember those, made by Loyds and sold at Pep Boys. You could see them fire after dark as the top brass had holes in them. They really did work! :encouragement: PJ
 
missing and gray smoke have stopped. All plugs a liitle black but has run a couple hundred miles, verses 20, and is nolonger missing or loading up. Plugs look black/gray and runs better than ever. Needs rebuild but is at least running better. Able to take mountain, hills in 4th and
accelerate, never went over 40 uphill before, so will be run as long as it holds together.
 
GREAT! And just in time to enjoy the fall color change.
 
bgtrn said:
just found them at local napa. had to find someone in store over 50, to know what i wanted, not kidding.
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bgtrn, were they Loyds plugs, or another brand? If Loyds, I didn't know they were still in business. PJ

Oh yeah, do you have a name? Sorry for not being bashful, but calling you and typing bgtrn is like typing a short code for a nuke installation. :jester:
 
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nameis dennis, oil plugs were from napa, will check with friend for name. we removed oil plug after 100 miles, as all smoke stopped. still no smoke with regular ngks and he just did 400 miles for the first time, in 10 years, in ny and pa mountains without fouling and climbed in 4th gear. porcelen is ly gray and a little soot on electrodes. note, didi not run well with champions. ngk best.
 
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