Idles - but nothing more
#81
11-26-2012, 04:10 AM
OK, I just want to confirm one thing. Back on page 1 you posted:
"I did not think the 86 had tps. I do see two micro switches on the throttle mechanics ( I cannot think this am what it is called ).
One activates just as the throttle cabe begins to move, the other when the thing is rotated about 15 degrees. I have checked both with a multimeter, for continuity, and for voltage thru it when each are activated."
I have to assume this is just a typo, BUT, is the throttle kickdown switch really engaging as soon as you move the throttle? You should actually have to work fairly hard with the pedal to the floor to get that switch to make. Again I'm assuming it's all in the way I'm reading this, but if your throttle cable seized up, and you're engaging the kickdown right away, perhaps the ECU is overfueling at part throttle and killing the engine?
D
"I did not think the 86 had tps. I do see two micro switches on the throttle mechanics ( I cannot think this am what it is called ).
One activates just as the throttle cabe begins to move, the other when the thing is rotated about 15 degrees. I have checked both with a multimeter, for continuity, and for voltage thru it when each are activated."
I have to assume this is just a typo, BUT, is the throttle kickdown switch really engaging as soon as you move the throttle? You should actually have to work fairly hard with the pedal to the floor to get that switch to make. Again I'm assuming it's all in the way I'm reading this, but if your throttle cable seized up, and you're engaging the kickdown right away, perhaps the ECU is overfueling at part throttle and killing the engine?
D
#82
11-26-2012, 04:44 AM
Greg,
I agree but it seems the TPS has been thoroughly tested and ruled out (although I still think those voltage readings should be verified back at the ECU plug).
After reading that I went back to the beginning and started reading through all the posts and found that. TPS notwithstanding, your kickdown switch should NOT engage as soon as you move the throttle cable. In fact neither of the switches on the capstan should, although it would be very difficult indeed to get the enrichment swicth to engage right off idle. It technically would be possible with the kickdown switch.
I think, but I'm not sure, that the ECU enriches further when the kickdown switch is engaged? Someone smarter can correct me on that.
I am sure I'm just reading the post wrong or something, but if either of those switches is making right off idle, there's a known problem that needs to be addressed before we move further.
Odd how those posts came up...
D
I agree but it seems the TPS has been thoroughly tested and ruled out (although I still think those voltage readings should be verified back at the ECU plug).
After reading that I went back to the beginning and started reading through all the posts and found that. TPS notwithstanding, your kickdown switch should NOT engage as soon as you move the throttle cable. In fact neither of the switches on the capstan should, although it would be very difficult indeed to get the enrichment swicth to engage right off idle. It technically would be possible with the kickdown switch.
I think, but I'm not sure, that the ECU enriches further when the kickdown switch is engaged? Someone smarter can correct me on that.
I am sure I'm just reading the post wrong or something, but if either of those switches is making right off idle, there's a known problem that needs to be addressed before we move further.
Odd how those posts came up...
D
#83
11-26-2012, 05:32 AM
Veteran Member
Sorry, lost track here.
A hard reset = disconnect battery -ve lead and hold it on the B+ post for a few seconds.
This drains all the capacitors (and of course defluxes the dilithium crystal) and forces the ECU to do a reboot.
It can do no harm.
ONLY DO THIS if you have your radio code if it needs one.
A hard reset = disconnect battery -ve lead and hold it on the B+ post for a few seconds.
This drains all the capacitors (and of course defluxes the dilithium crystal) and forces the ECU to do a reboot.
It can do no harm.
ONLY DO THIS if you have your radio code if it needs one.
#84
11-26-2012, 06:56 AM
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Actually, no. The fuel injection system has no idea if the kickdown switch is opened or closed. However, since the enrichment switch operates at about 75% throttle and the kickdown switch operates at 100+% throttle, you'd always have enrichment before you had kickdown.
I am sure I'm just reading the post wrong or something, but if either of those switches is making right off idle, there's a known problem that needs to be addressed before we move further.
Fixing would be required, yes. However, assuming the mixture isn't already over-rich from some other cause the engine should tolerate, perhaps even enjoy, the 13% enrichment at idle....if it *would* idle :-)
Not sure what would happen if the kickdown switch operates in "P" or when it shouldn't, but it might not be good :-)
Cheers
DD
#85
11-27-2012, 02:48 PM
You should have a switch "disconnecting" the lambda sensors at idle. Your car should also have a strange setup of a Throttle switch and a Throttle micro switch operating in paralell. Anybody care to enlighten me on the purpose? Either way, could you give us the colour of the wires going to each switch? Also, the way I read this is that both switches close when the throttle is moved, i.e. open circuit when at idle?
#86
11-28-2012, 03:41 PM
Per,
There are two micro switches on the Throttle switch. One has white with a gray stripe and black wire. The other (located right off the throttle cable) is green with a white stripe and solid green.
I have tried pulling these and creating an open curcuit as well as jumpering them with a wire (causing closed curcuit).
Are you thinking one of these is the "disconnect" lambda sensors at idle? Should there be voltage on one of these legs (if so how much)?
Thanks,
M.
There are two micro switches on the Throttle switch. One has white with a gray stripe and black wire. The other (located right off the throttle cable) is green with a white stripe and solid green.
I have tried pulling these and creating an open curcuit as well as jumpering them with a wire (causing closed curcuit).
Are you thinking one of these is the "disconnect" lambda sensors at idle? Should there be voltage on one of these legs (if so how much)?
Thanks,
M.
#87
11-28-2012, 08:44 PM
mquinn,
Can you confirm if either if the switches on the throttle capstan is making as soon as the throttle moves? This should not be the case.
The switch on the (US) driver's side of the capstan is the kickdown switch for the transmission and is activated by putting the throttle to the floor, then actually pushing just a hair further to move the actual cable sheath, which has a detent in it to engage the switch. Your earlier statement has me confused, because while I think it might be theoretically possible for your cable to sieze in the sheath and engage that switch right off idle, I've never heard of it.
The other switch triggers the ECU to enrich the fuel mixture at about 3/4 throttle. As you can see neither of these should enaae anywhere near idle or just off-idle.
Thanks,
D
Can you confirm if either if the switches on the throttle capstan is making as soon as the throttle moves? This should not be the case.
The switch on the (US) driver's side of the capstan is the kickdown switch for the transmission and is activated by putting the throttle to the floor, then actually pushing just a hair further to move the actual cable sheath, which has a detent in it to engage the switch. Your earlier statement has me confused, because while I think it might be theoretically possible for your cable to sieze in the sheath and engage that switch right off idle, I've never heard of it.
The other switch triggers the ECU to enrich the fuel mixture at about 3/4 throttle. As you can see neither of these should enaae anywhere near idle or just off-idle.
Thanks,
D
#88
11-29-2012, 07:28 AM
Darel,
The green/green-white is the micro switch on the drivers side of the captan - it looks to trigger off a detent on the throttle cable just as the cable begins to move. I do not see any adjustment to this other than the micro switch depth (which would change it only a degree or two). I think we are saying the same thing - but I am confusing you with my way of saying it. The switch activates in the "extended" position and closes the curcuit when it is in a detent. (I could test this with an ohm meter - but I just broke the switch pulling off the connection!!! It was a bit chilly this morning... brrrr and grrrr!).
the second microswitch is on the the passenger side and it is triggered at about 3/4 throttle.
I have disconnedted the green/green-white and tested but get no change. I have done the same for the other micro switch (one at a time, then both, then put them both back on).
There does not seem to be slack on the throttle cable - nor much tension when the peddle is in the "up" position (i.e. looks like full motion on the Throttle Sensor).
The green/green-white is the micro switch on the drivers side of the captan - it looks to trigger off a detent on the throttle cable just as the cable begins to move. I do not see any adjustment to this other than the micro switch depth (which would change it only a degree or two). I think we are saying the same thing - but I am confusing you with my way of saying it. The switch activates in the "extended" position and closes the curcuit when it is in a detent. (I could test this with an ohm meter - but I just broke the switch pulling off the connection!!! It was a bit chilly this morning... brrrr and grrrr!).
the second microswitch is on the the passenger side and it is triggered at about 3/4 throttle.
I have disconnedted the green/green-white and tested but get no change. I have done the same for the other micro switch (one at a time, then both, then put them both back on).
There does not seem to be slack on the throttle cable - nor much tension when the peddle is in the "up" position (i.e. looks like full motion on the Throttle Sensor).
#89
11-29-2012, 08:13 AM
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Darel,
The green/green-white is the micro switch on the drivers side of the captan - it looks to trigger off a detent on the throttle cable just as the cable begins to move. I do not see any adjustment to this other than the micro switch depth (which would change it only a degree or two). I think we are saying the same thing - but I am confusing you with my way of saying it. The switch activates in the "extended" position and closes the curcuit when it is in a detent. (I could test this with an ohm meter - but I just broke the switch pulling off the connection!!! It was a bit chilly this morning... brrrr and grrrr!).
The green/green-white is the micro switch on the drivers side of the captan - it looks to trigger off a detent on the throttle cable just as the cable begins to move. I do not see any adjustment to this other than the micro switch depth (which would change it only a degree or two). I think we are saying the same thing - but I am confusing you with my way of saying it. The switch activates in the "extended" position and closes the curcuit when it is in a detent. (I could test this with an ohm meter - but I just broke the switch pulling off the connection!!! It was a bit chilly this morning... brrrr and grrrr!).
Good, leave it broken for the time being!
Half the XJSs out there have broken kickdown switches and the owners don't even know it.
We're going off on a tangent with the kickdown switch. I respectfully suggest that you get the engine running properly and then worry about the transmission kickdown circuit :-)
the second microswitch is on the the passenger side and it is triggered at about 3/4 throttle.
Enrichment switch. Increases fueling by about 13% when activated. IMHO, if in doubt, leave it disconnected for the time being. We can come back to the enrichment circuit *after* we get the engine to the point where it'll run above idle speed.
Cheers
DD
#91
11-30-2012, 05:51 AM
So you are in fact comfirming that as soon as you step on the gas, the cable SHEATH moves and makes the kickdown switch. This means the cable is siezed within the sheath. I don't necessarily think this is a tangent. It is possible its related. Follow my logic here. We are familiar with bad engine grounds causing poor running issues. The cables are fairly well made and this is the first I've heard of on siezing. We know when you have a bad engine ground, the electrical aystem uses the throttle cable as a (poor) ground. Therefore, is it not entirely possible that the engine ground is bad, welded/melted the throttle cable, and is causing the stalling issue?
Fix your throttle cable, and use a set of jumper cables as a temporary ground cable and see what happens.
Fix your throttle cable, and use a set of jumper cables as a temporary ground cable and see what happens.
#92
11-30-2012, 06:50 AM
Darel, will leave both microswitches disconnected for now.
Do not know what you mean by the cable siezed in the sheath - pedal to throttle work fine. The detent in the cable is where the throttle is fully closed.
I can make a long 12g jumper from the battery to the engine - if that is what you are suggesting with the jumper cables. (or is there another grounding spot that you feel is weak?).
M.
Do not know what you mean by the cable siezed in the sheath - pedal to throttle work fine. The detent in the cable is where the throttle is fully closed.
I can make a long 12g jumper from the battery to the engine - if that is what you are suggesting with the jumper cables. (or is there another grounding spot that you feel is weak?).
M.
#93
11-30-2012, 07:45 AM
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Good :-)
Do not know what you mean by the cable siezed in the sheath - pedal to throttle work fine. The detent in the cable is where the throttle is fully closed.
Darel is quite correct in reminding us that a poorly grounded engine can cause throttle cable problems for exactly the reason stated.....the cable itself becomes the ground and overheats.
One possible clue would be the throttle cable getting hot while cranking the engine.
As for the physical location/relationship between the microswitch and the cable's detent thingy (grin) with the throttle at idle position I wonder if the cable is out of adjustment? Right know I don't have a V12 in front of me anf my memory is a bit foggy....but it seems like the adjustment at the throttle capstain bracket would alter the relationship between the outer sheath and the inner cable. I dunno
In any case, yes, good advice to make sure the engine is grounded
I can make a long 12g jumper from the battery to the engine - if that is what you are suggesting with the jumper cables. (or is there another grounding spot that you feel is weak?).
M.
M.
Not 100% sure what Darel is suggesting with the jumper cables....perhaps runing a cable from the engine to the battery "-" post? Or perhaps at least from the engine block to the subframe? But, wherever he intends it be attached the idea obviously is to ensure the engine is grounded
The original ground strap, as I recall, is down near the left engine mount. It can be checked/removed/cleaned or you can add a redundant ground cable if you like, perhaps on the other side of the engine? Whatever is easiest.
As long as the subject of ground has come up I think it is most important to verify that the ECU is grounded....if it already hasn't been done. As I recall the ECU grounds to a nearby bolt, perhaps with several other circuits. Someone with a less foggy memory can chime in on that
Cheers
DD
#94
11-30-2012, 08:52 PM
#95
12-01-2012, 05:40 AM
Yup, that's it. I was suggesting as Doug correctly surmised that you just put a jumper cable on the "-" post then somewhere on the engine, but adding an additional 12g wire ground from the engine to somewhere in the bay is a good idea anway. I did just that, using the bolt that holds the radiator support plate, and I definitely noticed my car running a little better and charging MUCH better. And I wasn't really having any issues prior to that, it's just something I do on all my old cars. And yes, clean up and check your ECU ground.
Let us know if it helps at all.
D
Let us know if it helps at all.
D
#96
12-01-2012, 09:07 AM
Hate to chime in late but have you swapped out the ignition amp? My 86 C10 PU did exactly the same thing with a failed GM, HEI amp (same one in your car) idle but no throttle up allowed, followed by rough idle then no start...then sometimes start etc. Easy to get a bad one from new too.......from Kirby's book.. (sorry if you've looked into the amp already....didn't read the whole thread...I'm rooting for ya!)
IGNITION AMPLIFIER -- REPAIR: The Lucas Constant Energy ignition amplifier is a black plastic box mounted on
top of the left intake manifold. This unit is clearly labeled “Lucas” and “Made in UK”. The mail-order catalogs call for
a part number DAB106, and want serious $$$ for it.
If you unbolt this unit from the intake manifold, turn it over, remove four tiny screws and remove the cover, you will
see four components inside. The predominant component is a GM High Energy Ignition (HEI) module. This unit is so
common that you can find it on a bubble card hanging from a hook in any department store with an automotive section
-- for around $20. Usually this amplifier can be repaired by simply replacing the GM HEI module for considerably less
than the cost of replacing the whole unit.
Simple? Maybe not. Dave Johnson says, “The amp on my ’84 died on me several years ago. I replaced the module
with the equivalent GM module and it lasted 3 months. I replaced the zener and the capacitor with equivalents. I again
replaced the module. This one lasted 1 month. I gave them one more chance (lifetime warranty) and it's worked for 4
years now. The moral of the story? I believe the modules available from discounters are marginal and you have to
keep trying to get a good one. Since I didn't even consider buying a new amp from the dealer I can't rate their failure
rate but a GM mechanic friend of mine kept after me that the modules I was getting were junk. He was right and I now
have a working one. No more intermittent problems. Try another one.”
Tom Drakos concurs: “After buying 3 different control modules all made by Wells, DR100, I got 3 different types of
results, all of which were terrible, to the point of undrivable. I knew the original was made by GM, so I searched the
internet looking for a similar application. I ended up with a control module made by AC Delco, part # D1906, even hastop of the left intake manifold. This unit is clearly labeled “Lucas” and “Made in UK”. The mail-order catalogs call for
a part number DAB106, and want serious $$$ for it.
If you unbolt this unit from the intake manifold, turn it over, remove four tiny screws and remove the cover, you will
see four components inside. The predominant component is a GM High Energy Ignition (HEI) module. This unit is so
common that you can find it on a bubble card hanging from a hook in any department store with an automotive section
-- for around $20. Usually this amplifier can be repaired by simply replacing the GM HEI module for considerably less
than the cost of replacing the whole unit.
Simple? Maybe not. Dave Johnson says, “The amp on my ’84 died on me several years ago. I replaced the module
with the equivalent GM module and it lasted 3 months. I replaced the zener and the capacitor with equivalents. I again
replaced the module. This one lasted 1 month. I gave them one more chance (lifetime warranty) and it's worked for 4
years now. The moral of the story? I believe the modules available from discounters are marginal and you have to
keep trying to get a good one. Since I didn't even consider buying a new amp from the dealer I can't rate their failure
rate but a GM mechanic friend of mine kept after me that the modules I was getting were junk. He was right and I now
have a working one. No more intermittent problems. Try another one.”
Tom Drakos concurs: “After buying 3 different control modules all made by Wells, DR100, I got 3 different types of
results, all of which were terrible, to the point of undrivable. I knew the original was made by GM, so I searched the
#97
12-02-2012, 06:24 AM
#98
12-02-2012, 06:40 AM
#99
12-02-2012, 07:40 AM
#100
12-02-2012, 09:36 AM
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The module inside the amp looks like this:
NAPA AUTO PARTS
AC Delco number D1906
GM number 10482820 or 19180771
Napa number TP45
Accel number 35361
Standard Motor Products LX301
Should be about $25-$50
Cheers
DD
NAPA AUTO PARTS
AC Delco number D1906
GM number 10482820 or 19180771
Napa number TP45
Accel number 35361
Standard Motor Products LX301
Should be about $25-$50
Cheers
DD