A flash of light!?!?!?!
01-27-2003, 12:16 PM
#31
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Since the distributor pickup is responsible for the tach signal as well as the ignition, if the miss is in the pickup, the tach should drop when the miss ocurrs.
01-27-2003, 06:29 PM
#32
Nordschleife Master
Thread Starter
OK, I'm confused now.
As far as I can tell, there are two or three sencors we're talking about.
A "speed" sencor, a TDC sencor, and the ignition pick up. Which if, any are the same sencor?
I was under the impression that the TDS and the "speed" where on the rear side of the motor, while the ignition pick up was inside the distributer???? Now it seems that the TDS is on the back side, the "speed" sencor somewhere on the frount, and the ignition pick up in some unknown place.
I'm confused!!!!
Help!
As far as I can tell, there are two or three sencors we're talking about.
A "speed" sencor, a TDC sencor, and the ignition pick up. Which if, any are the same sencor?
I was under the impression that the TDS and the "speed" where on the rear side of the motor, while the ignition pick up was inside the distributer???? Now it seems that the TDS is on the back side, the "speed" sencor somewhere on the frount, and the ignition pick up in some unknown place.
I'm confused!!!!
Help!
01-27-2003, 06:51 PM
#33
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ya gots no TDC sencor on yer '83.
The L-Jet references the tach signal from the ignition control unit, which is received from the magnetic pickup (pulse generator) in the distributor to which Wally refers. That's all there is.
The only other speed sensor is the speedo sender on the differential cover.
The L-Jet references the tach signal from the ignition control unit, which is received from the magnetic pickup (pulse generator) in the distributor to which Wally refers. That's all there is.
The only other speed sensor is the speedo sender on the differential cover.
01-27-2003, 07:03 PM
#34
Nordschleife Master
I guess I was told wrong then. If so, my bad V.U. and I apologize.
So from 83-84, the speend sensor (and TDC) was added to the bell housing?. (Rear of motor and underneath the air box towards the firewall)
HHMMMMMM
So from 83-84, the speend sensor (and TDC) was added to the bell housing?. (Rear of motor and underneath the air box towards the firewall)
HHMMMMMM
01-27-2003, 07:04 PM
#35
Nordschleife Master
Thread Starter
Thanks
So that one, possibly flacky, sencor controls everything!?!?!?!?! I better go buy a new sencor, just in case!
Does anyone have any suggestions on where to look for information regarding testing that sencor? I haven't the foggyest clue exactly how it works, or what it looks like.
I'm not realy even sure what to call the thing, so I'm not realy sure what to search the archives for. Also, I looked and didn't see any saved threads on it on Greg's site.
Thank you for your help so far. I'm a bit closer to understanding the system!
Btw, Drew don't worry about being wrong. Once I would have sworn that my car had adjustable cam pullys. I was later informed otherwise. Opps. I looked at it closely too!
According to John, all of the L-jetronic cars where like that. That means all US cars from 80-84. In 85, I guess they would have had to add the TDC for the LH-jetronic of the new 5.0 liter. I guess the Euro cars would have gotten it in 84 with the introduction of the S2? Aeter all the CIS cars wouldn't have it.
So that one, possibly flacky, sencor controls everything!?!?!?!?! I better go buy a new sencor, just in case!
Does anyone have any suggestions on where to look for information regarding testing that sencor? I haven't the foggyest clue exactly how it works, or what it looks like.
I'm not realy even sure what to call the thing, so I'm not realy sure what to search the archives for. Also, I looked and didn't see any saved threads on it on Greg's site.
Thank you for your help so far. I'm a bit closer to understanding the system!
Btw, Drew don't worry about being wrong. Once I would have sworn that my car had adjustable cam pullys. I was later informed otherwise. Opps. I looked at it closely too!
According to John, all of the L-jetronic cars where like that. That means all US cars from 80-84. In 85, I guess they would have had to add the TDC for the LH-jetronic of the new 5.0 liter. I guess the Euro cars would have gotten it in 84 with the introduction of the S2? Aeter all the CIS cars wouldn't have it.
01-27-2003, 07:36 PM
#36
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This was actually my very first question posted here - I was looking for the invisible TDC sensor and was set straight by, I believe, Steve C.
VU, it works real simply. If you pull the distributor cap, you'll see a spiked plate mounted at the same height as the green cable connection. As the distributor turns, this trigger wheel moves past a magnetic pickup coil and induces voltage into the coil, which is transmitted to the ignition module and to the tach. The ignition uses this pulse to determine where the engine is in its rotation and then do all the other things that ignitions do.
The manual way to test it - pull the plug from the ignition module and connect your meter across terminals 7 and 31d. Coil resistance should be 485-700 ohms.
If you want to test it the backyard (backwoods?) way, and are feeling ambitious, pull the distributor (but DON'T do this unless you're sure you can get it back in and aligned correctly), hook up your DVOM to the point where the green wire exits the distributor, set it to AC Voltage, and spin the distributor shaft. You should see a voltage signal, increasing with speed of rotation, and inverting (+/-) at what appear to be uneven intervals. Use an oscilloscope to see the actual wave. Since your car runs, though, and you'll never be able to spin the bastard at anything approaching engine speed, finding an intermittent fault this way is really unlikely; usually best to use in the case of total failure.
Don't forget that the ignition is a system, and there are a whole bunch of other components that could be causing your flake-out.
VU, it works real simply. If you pull the distributor cap, you'll see a spiked plate mounted at the same height as the green cable connection. As the distributor turns, this trigger wheel moves past a magnetic pickup coil and induces voltage into the coil, which is transmitted to the ignition module and to the tach. The ignition uses this pulse to determine where the engine is in its rotation and then do all the other things that ignitions do.
The manual way to test it - pull the plug from the ignition module and connect your meter across terminals 7 and 31d. Coil resistance should be 485-700 ohms.
If you want to test it the backyard (backwoods?) way, and are feeling ambitious, pull the distributor (but DON'T do this unless you're sure you can get it back in and aligned correctly), hook up your DVOM to the point where the green wire exits the distributor, set it to AC Voltage, and spin the distributor shaft. You should see a voltage signal, increasing with speed of rotation, and inverting (+/-) at what appear to be uneven intervals. Use an oscilloscope to see the actual wave. Since your car runs, though, and you'll never be able to spin the bastard at anything approaching engine speed, finding an intermittent fault this way is really unlikely; usually best to use in the case of total failure.
Don't forget that the ignition is a system, and there are a whole bunch of other components that could be causing your flake-out.
01-27-2003, 11:58 PM
#37
Nordschleife Master
Thread Starter
Thanks for the tip.
Like what else could cause my flack out?
Other than a flacky transisterized unit, only thing I could see from the wireing diagrams was the connecters. I found two, are there any more that I should be looking for?
Rember, the rotor, cap, wires, the green wire, and coil are all almost new. I'm going to replace the spark plugs he realy soon, as I've got no record of them being changed.
One problem at a time I guess.
Like what else could cause my flack out?
Other than a flacky transisterized unit, only thing I could see from the wireing diagrams was the connecters. I found two, are there any more that I should be looking for?
Rember, the rotor, cap, wires, the green wire, and coil are all almost new. I'm going to replace the spark plugs he realy soon, as I've got no record of them being changed.
One problem at a time I guess.
