Rough Running

neuropel · 04-20-2005

My manta has suddenly started running like crap. It started backfiring and missing under load today on my drive home from work. Ignition is via a pertronix, and the cap and rotor are bosch units purchased new last year (less than a thousand miles on them). Coil is relatively new also...when I pulled the plug wires from the distributor there's PLENTY of spark.
I pulled the plugs (also replaced not all that long ago) tonight and they looked to be nice and dry. #1 and #2 were a wee bit sooty, but not bad at all.
The car has also developed some other oddities in recent weeks. I notice that when I start it in the morning it really misses badly, like one cylinder is not firing at all. After it's warmed up for a minute or so, it smooths out, then as I'm driving it at highway speed it develops a VERY loud tick that I think is lifter noise. There's also a rattle that I suspect is timing chain (not too worried about that one). My question to the group is, what kind of mileage do you typically get out of a tune up? I was thinking once I got away from points I'd be going longer between tune ups, but perhaps I'm wrong? And where should I start with trying to eliminate the lifter noise? I'm on a tight schedule between now and Carlisle...I'll probably just throw new parts on it and hope for the best, but I'd still be curious to hear suggestions.
Last time I checked compression on the motor it was pretty good (can't remember details, but it was sound on all 4 cylinders).
Thanks
Todd K.

neuropel · 04-20-2005

An Update:
I popped off the distributor cap this morning just to check things out and found that the small braided wire attached to the inside of the distributor is down to a single strand!
It doesn't look to be easily replaced. Any suggestions on how to proceed? I don't even know what it does, but it appears to be a ground wire (it's tied to the wall of the distributor).
Source of my poor running condition perhaps?

73Manta72gt · 04-20-2005

I think that is the ground strap for the breaker points....seems like it's welded to the distributor housing

BQS4 · 04-20-2005

Todd;
That strand of braided wire is just soldered to the breaker plate and the side of the dist. If you don't want to try and solder it, or it won't solder, let me know, I have a 74 dist in a Rallye I'm stripping and I can drop it on UPS, if you need it. But, as for your rough running, I'd check all the base line stuff first, to make sure it's correct (timing marks, dwell, etc) and go from there.
Gene

73Manta72gt · 04-20-2005

I got 40K miles from a set of points...I changed them just because it had been so many miles. You might want to roll the engine over by hand with the valve cover off and see that the valves are opening properly. The problem reminds me of a 318cu engine I worked on that had the camshaft lobes worn for the exhaust valve on a few cylinders.

neuropel · 04-22-2005

Originally Posted by BQS4

Todd;
That strand of braided wire is just soldered to the breaker plate and the side of the dist. If you don't want to try and solder it, or it won't solder, let me know, I have a 74 dist in a Rallye I'm stripping and I can drop it on UPS, if you need it. But, as for your rough running, I'd check all the base line stuff first, to make sure it's correct (timing marks, dwell, etc) and go from there.
Gene

The wire looks almost like solder wick, anything special about it?
If this wire breaks, am I dead in the water?
Any chance of damaging my Pertronix unit if this ground breaks?

namba209 · 04-22-2005

Todd, yes, you will be dead in the water if that wire breaks, that is the triggering wire to charge up the coil. When the points are closed voltage flows through the coil to ground through that wire. When the points open current flow stops and the stored energy in the coil is routed to a spark plug by the rotor in and out of the distributor cap, thereby creating the ignition spark. Or a reasonable facsimile thereof.

neuropel · 04-22-2005

Apparently with a Pertronix, the wire isn't needed (got that from a reliable source). Anyone have other experiences?
I'm still going to replace the wire because I keep a spare set of points in the glove box just in case. If the pertronix fails, THEN I'm dead in the water.

BQS4 · 04-22-2005

Dude;
If the repair doesn't work, give me a buzz, I have a 74 dist right here.
Gene

neuropel · 04-22-2005

Thanks Gene. I'll know one way or the other soon hopefully.

04-20-2005	#1 (permalink)
neuropel Rice Cooker Join Date: May 2002 Location: Spring Church, PA Posts: 1,787	Unanswered: Rough Running My manta has suddenly started running like crap. It started backfiring and missing under load today on my drive home from work. Ignition is via a pertronix, and the cap and rotor are bosch units purchased new last year (less than a thousand miles on them). Coil is relatively new also...when I pulled the plug wires from the distributor there's PLENTY of spark. I pulled the plugs (also replaced not all that long ago) tonight and they looked to be nice and dry. #1 and #2 were a wee bit sooty, but not bad at all. The car has also developed some other oddities in recent weeks. I notice that when I start it in the morning it really misses badly, like one cylinder is not firing at all. After it's warmed up for a minute or so, it smooths out, then as I'm driving it at highway speed it develops a VERY loud tick that I think is lifter noise. There's also a rattle that I suspect is timing chain (not too worried about that one). My question to the group is, what kind of mileage do you typically get out of a tune up? I was thinking once I got away from points I'd be going longer between tune ups, but perhaps I'm wrong? And where should I start with trying to eliminate the lifter noise? I'm on a tight schedule between now and Carlisle...I'll probably just throw new parts on it and hope for the best, but I'd still be curious to hear suggestions. Last time I checked compression on the motor it was pretty good (can't remember details, but it was sound on all 4 cylinders). Thanks Todd K. __________________ "In the end, it's not the years in your life that count. It's the life in your years." -Abraham Lincoln ________________ 1972 GT 2.4L 1974 Manta GT/E 2.2L 1973 Manta Rallye 2.5L

04-20-2005	#2 (permalink)
neuropel Rice Cooker Join Date: May 2002 Location: Spring Church, PA Posts: 1,787	Yikes! An Update: I popped off the distributor cap this morning just to check things out and found that the small braided wire attached to the inside of the distributor is down to a single strand! It doesn't look to be easily replaced. Any suggestions on how to proceed? I don't even know what it does, but it appears to be a ground wire (it's tied to the wall of the distributor). Source of my poor running condition perhaps? __________________ "In the end, it's not the years in your life that count. It's the life in your years." -Abraham Lincoln ________________ 1972 GT 2.4L 1974 Manta GT/E 2.2L 1973 Manta Rallye 2.5L

04-20-2005	#4 (permalink)
BQS4 Southern Red Neck Join Date: Mar 2002 Location: Snellville, GA Posts: 6,028 Real Name: Gene Provided Answers: 12	Todd; That strand of braided wire is just soldered to the breaker plate and the side of the dist. If you don't want to try and solder it, or it won't solder, let me know, I have a 74 dist in a Rallye I'm stripping and I can drop it on UPS, if you need it. But, as for your rough running, I'd check all the base line stuff first, to make sure it's correct (timing marks, dwell, etc) and go from there. Gene __________________ "Yes, I do have a rifle rack in my Sportwagon"

04-22-2005	#7 (permalink)
namba209 6,000 Post Club Join Date: Aug 2002 Location: Imperial Beach, CA South of San Diego Posts: 6,054 Provided Answers: 6	Todd, yes, you will be dead in the water if that wire breaks, that is the triggering wire to charge up the coil. When the points are closed voltage flows through the coil to ground through that wire. When the points open current flow stops and the stored energy in the coil is routed to a spark plug by the rotor in and out of the distributor cap, thereby creating the ignition spark. Or a reasonable facsimile thereof. __________________ Ron 72 GT 3.4L V-6/T-5/ZF posi - almost done - Just need AC installed. 75 Chevy monza 5.7L/TH350/Auburn 3.08 posi - Next

04-22-2005	#8 (permalink)
neuropel Rice Cooker Join Date: May 2002 Location: Spring Church, PA Posts: 1,787	Apparently with a Pertronix, the wire isn't needed (got that from a reliable source). Anyone have other experiences? I'm still going to replace the wire because I keep a spare set of points in the glove box just in case. If the pertronix fails, THEN I'm dead in the water. __________________ "In the end, it's not the years in your life that count. It's the life in your years." -Abraham Lincoln ________________ 1972 GT 2.4L 1974 Manta GT/E 2.2L 1973 Manta Rallye 2.5L

04-20-2005	#3 (permalink)
73Manta72gt Member Join Date: Nov 2002 Location: Winston-Salem, NC Posts: 341	I think that is the ground strap for the breaker points....seems like it's welded to the distributor housing

04-20-2005	#5 (permalink)
73Manta72gt Member Join Date: Nov 2002 Location: Winston-Salem, NC Posts: 341	I got 40K miles from a set of points...I changed them just because it had been so many miles. You might want to roll the engine over by hand with the valve cover off and see that the valves are opening properly. The problem reminds me of a 318cu engine I worked on that had the camshaft lobes worn for the exhaust valve on a few cylinders.

04-22-2005	#9 (permalink)
BQS4 Southern Red Neck Join Date: Mar 2002 Location: Snellville, GA Posts: 6,028 Real Name: Gene Provided Answers: 12	Dude; If the repair doesn't work, give me a buzz, I have a 74 dist right here. Gene __________________ "Yes, I do have a rifle rack in my Sportwagon"

04-22-2005	#10 (permalink)
neuropel Rice Cooker Join Date: May 2002 Location: Spring Church, PA Posts: 1,787	Thanks Gene. I'll know one way or the other soon hopefully. __________________ "In the end, it's not the years in your life that count. It's the life in your years." -Abraham Lincoln ________________ 1972 GT 2.4L 1974 Manta GT/E 2.2L 1973 Manta Rallye 2.5L

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