Tach not winding up with engine
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Tach not winding up with engine
Hey Guys, hoping you could help with the tach issues I’m having in my 1971 350 4spd. Upon start up the tach reads normal idle RPMs. But, as you accelerate, or even at idle it wont rev past about 22-2500 RPMs. When you shut the ignition the needle buries over to past redline instead of 0. Up on start up it zero’s out then shows idle RPMs.
It has an MSD 8360 Pro Billet dist that was previously installed with the engine rebuild. There are 3 wires that come out from the bottom of the dist. A red one which goes to the pos of the coil. An orange one which goes to the neg side of the coil, and a blk one to a (gnd).
There are also 2 other yellow wires hooked up to the coil. One wire is connected to the neg side, the other is also yellow but more like a braided type wire. Both disappear into wire looms. I don’t know where to start looking for the problem. Is it possible that the MSD dist isnt the correct one?
Any help is appreciated, Thanks, Steve
It has an MSD 8360 Pro Billet dist that was previously installed with the engine rebuild. There are 3 wires that come out from the bottom of the dist. A red one which goes to the pos of the coil. An orange one which goes to the neg side of the coil, and a blk one to a (gnd).
There are also 2 other yellow wires hooked up to the coil. One wire is connected to the neg side, the other is also yellow but more like a braided type wire. Both disappear into wire looms. I don’t know where to start looking for the problem. Is it possible that the MSD dist isnt the correct one?
Any help is appreciated, Thanks, Steve
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Thanks for the fast reply. It looks just like the OE tach. That’s all I know about it. Even with all the receipts that came with the car I didn’t see anything about an elec tach. What you said makes sense though. I saw a different MSD dist that shows a hole for the cable driven tach. Im wondering if those two other yellow wires have anything to do with it. Im going to look thru those receipts again.
Drifting
Joined: Jun 2025
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Any chance of getting info from PO or from his mechanics ?
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Thank you Rebelyell. The PO didn’t have any info from the guy he bought it from who installed the Ecklers Tach. I will start with the wiring diagram.
Burning Brakes
Joined: Apr 2020
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From: Western NY
The yellow braided wire that is not connected sounds like the wire that comes from the solenoid and supplies 12v to the coil/points while cranking only - I think. since you have an MSD dist. you do not need that wire. don't cut it off just tape it or zip tie it out of the way. sounds like the po probably added an electronic tach conversion kit to the tach since he changed the dist and eliminated the mechanical tach drive.
Pat
Pat
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The yellow braided wire that is not connected sounds like the wire that comes from the solenoid and supplies 12v to the coil/points while cranking only - I think. since you have an MSD dist. you do not need that wire. don't cut it off just tape it or zip tie it out of the way. sounds like the po probably added an electronic tach conversion kit to the tach since he changed the dist and eliminated the mechanical tach drive.
Pat
Pat
1967 Pedal Car Champion
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From: US-PNW
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Last question…Can I remove the tach w/o removing the entire dash?
Thanks guys.
Burning Brakes
Joined: Apr 2020
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From: Western NY
You will need to remove the tach speedo cluster only. the center gauge cluster and passenger side do not need to be removed. unbolt the 2 bolts that hold the steering column up and let the column hang down a little otherwise it will be very difficult to remove the speedo/tach cluster without cracking the fiberglass behind the Vinal covering. ask me how I know. . . . .
Pat
Pat
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You will need to remove the tach speedo cluster only. the center gauge cluster and passenger side do not need to be removed. unbolt the 2 bolts that hold the steering column up and let the column hang down a little otherwise it will be very difficult to remove the speedo/tach cluster without cracking the fiberglass behind the Vinal covering. ask me how I know. . . . .
Pat
Pat
Drifting
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Yes. It does. So, I got to the bottom of it. I found the original receipt, the tach was sent to D&M Restorations in SC, in 2010. They converted it to an electronic tach. Using their circuit board, and reusing the OE face. I spoke to someone there who told me the yel wire to the neg side of the coil is for the tach, which reads RPM. There’s a hot wire, to IGN, and a Gnd wire. I disconnected the yel wire at the neg side of the coil and the tach did not work. He said most likely the circuit board is bad. I’d have to remove it and send it in.
Last question…Can I remove the tach w/o removing the entire dash?
Thanks guys.
Last question…Can I remove the tach w/o removing the entire dash?
Thanks guys.
If so, a suggestion:
While you're removing tach, Also remove speedo and send it along with tach; have D&M clean & service both.
Upon reassembly, also R&R all dash lamps within reach And properly lube speedo cable.
*When servicing driver's dash, I've found it Very helpful to begin job by removing driver seat from cabin; easier on spine etc.
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Seems you plan to remove tach and return it to D&M for service.
If so, a suggestion:
While you're removing tach, Also remove speedo and send it along with tach; have D&M clean & service both.
Upon reassembly, also R&R all dash lamps within reach And properly lube speedo cable.
*When servicing driver's dash, I've found it Very helpful to begin job by removing driver seat from cabin; easier on spine etc.
If so, a suggestion:
While you're removing tach, Also remove speedo and send it along with tach; have D&M clean & service both.
Upon reassembly, also R&R all dash lamps within reach And properly lube speedo cable.
*When servicing driver's dash, I've found it Very helpful to begin job by removing driver seat from cabin; easier on spine etc.
thank u for that tip. What lube should I use for the speedo cable?
Safety Car
Joined: May 2001
Posts: 4,754
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From: Fairfax Virginia
Hello motionfan,
I noticed that you asked about a good speedometer cable lubricant. That has been an interesting point here on the Forum as many people have many opinions regarding the proper cable lubricant.
I might suggest that you use either a White Lithium Grease or a Dry Graphite lubricant. I even found a site that suggested that you mix White Lithium grease with Dry Graphite until you have a black paste and then use it on the cable itself before putting it back in the cable housing. I have used White Lithium grease before and it always worked well. I personally remove the cable from the housing to clean the cable before applying grease to the cables and then replacing the cable into the housing pre-greased. If you simply spray the grease into the tube you will likely have a blockage where the grease stopped moving.
Applying dry graphite is a good dry lubricant but it requires all the grease and remnants removed and cleaned off before applying. It can also move down the tube and collect someplace you don't want it to collect.
I noticed that you asked about a good speedometer cable lubricant. That has been an interesting point here on the Forum as many people have many opinions regarding the proper cable lubricant.
I might suggest that you use either a White Lithium Grease or a Dry Graphite lubricant. I even found a site that suggested that you mix White Lithium grease with Dry Graphite until you have a black paste and then use it on the cable itself before putting it back in the cable housing. I have used White Lithium grease before and it always worked well. I personally remove the cable from the housing to clean the cable before applying grease to the cables and then replacing the cable into the housing pre-greased. If you simply spray the grease into the tube you will likely have a blockage where the grease stopped moving.
Applying dry graphite is a good dry lubricant but it requires all the grease and remnants removed and cleaned off before applying. It can also move down the tube and collect someplace you don't want it to collect.
Drifting
Joined: Jun 2025
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* too much cable lube and it WILL creep up and into mechanical speedo head (same for mech tach head). There's a magnetic drum that spins in there and if it gets lube it WILL foul it and require R&R and service.
Suggest ask D&M for their most recent recommendation of type/brand lube and quantity.
OTOH
https://atpautomotive.com/speedometer-lubricant
Suggest ask D&M for their most recent recommendation of type/brand lube and quantity.
OTOH
https://atpautomotive.com/speedometer-lubricant
Thread Starter
Instructor
Joined: Apr 2025
Posts: 159
Likes: 45
Hello motionfan,
I noticed that you asked about a good speedometer cable lubricant. That has been an interesting point here on the Forum as many people have many opinions regarding the proper cable lubricant.
I might suggest that you use either a White Lithium Grease or a Dry Graphite lubricant. I even found a site that suggested that you mix White Lithium grease with Dry Graphite until you have a black paste and then use it on the cable itself before putting it back in the cable housing. I have used White Lithium grease before and it always worked well. I personally remove the cable from the housing to clean the cable before applying grease to the cables and then replacing the cable into the housing pre-greased. If you simply spray the grease into the tube you will likely have a blockage where the grease stopped moving.
Applying dry graphite is a good dry lubricant but it requires all the grease and remnants removed and cleaned off before applying. It can also move down the tube and collect someplace you don't want it to collect.
I noticed that you asked about a good speedometer cable lubricant. That has been an interesting point here on the Forum as many people have many opinions regarding the proper cable lubricant.
I might suggest that you use either a White Lithium Grease or a Dry Graphite lubricant. I even found a site that suggested that you mix White Lithium grease with Dry Graphite until you have a black paste and then use it on the cable itself before putting it back in the cable housing. I have used White Lithium grease before and it always worked well. I personally remove the cable from the housing to clean the cable before applying grease to the cables and then replacing the cable into the housing pre-greased. If you simply spray the grease into the tube you will likely have a blockage where the grease stopped moving.
Applying dry graphite is a good dry lubricant but it requires all the grease and remnants removed and cleaned off before applying. It can also move down the tube and collect someplace you don't want it to collect.