What does the speed sensor do on the 84 tudor? I do have crusie control and it still works fine along with my speedo but i was reading online the cfi 5.0s used the speed sensor to also send a pulse to the throttle kicker to apply part throttle while decelerating. reason why is my throttle kicker is working but only during warm up or if i switch the a/c to the on position but does not working during decelaration. It used to work but some how stopped about a year ago. I did replaced the throttle kicker along with the votm vacuum sensing switch thats on the valve cover but its still having a rough decel. Is it possible that the speed sensor is shot and its not sending the pulse to the votm which in return isnt supplying vacuum to the throttle kicker? I would like to fix this because my decel is pretty rough sometimes but this is also happening in the 86 cp. If its not the speed sensor then i still have to check the timing chains on both cars.
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1984 mercury grand marquis ls rebuilt 306 flat top pistons with factory cfi and lincoln headers with single glasspack dual snorkle air cleaner. Gloss black paint with slick top coversion.
1986 mercury grand marquis colony park 5.0 sefi dual exhuast thrush turbos with h pipe and turbines -
It works the cruise control. Thats it. No connection to the ECM at all. That change happened around 1988 with the integrated cruise control.86 Lincoln Town Car (Galactica).
5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley
91 Lincoln Mark VII LSC grandpa spec white and cranberry
1984 Lincoln Continental TurboDiesel - rolls coal
Originally posted by phayzer5
I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers
Everything looks like voodoo if you don't understand how it works -
That is weird. There has to be something that sends a pulse to the votm for the decel rpm to kick on. Its in my Hanse manual for the 84 cfi and it says if the throttle kicker is good along with the votm then check the speed sensor as long if the car came with cruise control. Maybe there is a vacuum sensing switch that looks for increase or decrease in vacuum then sends a pulse to the votm to supply vacuum to the kicker. I think the sefi cars had something to that increased the idle during deceleration. Wasn't it like a fuel a fuel cut off switch? I looked on rock auto and there only 12 bucks for the speed sensor so its not expensive at all. If not then im thinking the timing chain in both the cars might be the culprit to the decel roughness as the chains might be tightening and loosening. It feels like the cars are being pushed forward then pulled back and the exhaust sounds like blaaa mmm blaa mmm blaaa mmm blaaa till about 25 mph then its quiet and smooth. However i did notice in the 84 cfi if i supply power for the votm to stay on and supply slight vacuum to the kicker the decel is smooth as butter but down side is the idle is increased at stops. Do any of your guys 5.0 do this to or is it just me. Like i said the 84 never did this till about a year ago and the 86 has done it for a lot longer but has progressively gotten worse.1984 mercury grand marquis ls rebuilt 306 flat top pistons with factory cfi and lincoln headers with single glasspack dual snorkle air cleaner. Gloss black paint with slick top coversion.
1986 mercury grand marquis colony park 5.0 sefi dual exhuast thrush turbos with h pipe and turbinesComment
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Nope, at least not on anything 87 and older. I'm reasonably sure it works it out based on MAP and TPS. MAP should signal very high vacuum, TPS should signal closed or nearly so. Its been a while but I seem to recall my 86 wasn't exactly silky smooth on decel when it had the original motor. I always suspected it was the shot to hell trans mount or the broken trans crossmember. I actually only drove that car for about 3 months with the stock motor in it, and I bought it way back in 2004 so my memory is hazy here.
If the chain has significant slack in it, you can see that by pulling the cap off and rocking the crankshaft while watching the rotor. If you can move the crankshaft before the rotor starts to turn, thats the slack in the chain. You'll probably also see this as the timing marks dancing around a bit with the SPOUT unplugged. 86+ tends to not have the shitty timing chain, but its not an absolute guarantee.86 Lincoln Town Car (Galactica).
5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley
91 Lincoln Mark VII LSC grandpa spec white and cranberry
1984 Lincoln Continental TurboDiesel - rolls coal
Originally posted by phayzer5
I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers
Everything looks like voodoo if you don't understand how it worksComment
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I'm going to change the speed sensor in my 86 probably tomorrow. I'll let you know if I see any changeComment
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Found this TSB
Didn't get a chance to change mine yesterday, but....Originally posted by meandad View Post
I found reference to this TSB stating that "some" 86-91 models used the IVSC, and do connect to the ECM
Cruise (Speed) Control (Vacuum) "TRICKS OF THE TRADE" Troubleshooting TSB 90-25-12 by Ford for 86-91 Bronco, Aerostar, Econoline, Explorer, F-150, F-250, F-350, Ranger & cars
Source: by Ford via miesk5 (Al) at Miesk5's Home Page of Big Bronco Links home.comcast.net
PUBLICATION DATE: December 7, 1990
FORD
1986-91 Crown Victoria, Escort, Mustang, Taurus, Tempo, Thunderbird
1990-92 Probe
LINCOLN-MERCURY
1986-87 Lynx
1986-91 Continental, Cougar, Grand Marquis, Mark VII, Sable, Topaz, Town Car
LIGHT TRUCK
1986-90 Bronco II
1986-91 Aerostar, Bronco, Econoline, Explorer, F-150, F-250, F-350, Ranger
1988-91 F Super Duty
ISSUE Integrated Vehicle Speed Control (IVSC) was introduced on some 1986 units. The IVSC system uses the EEC IV processor as the control module. Before IVSC a Stand Alone Speed Control System was used on all applications. The Stand Alone Speed Control System uses a separate control amplifier.
ACTION Refer to the following diagnostic information when servicing speed control concerns. Refer to the Speed Control System Application chart to determine which type of system is used for a specific model.Comment
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thats an interesting bit there.1984 mercury grand marquis ls rebuilt 306 flat top pistons with factory cfi and lincoln headers with single glasspack dual snorkle air cleaner. Gloss black paint with slick top coversion.
1986 mercury grand marquis colony park 5.0 sefi dual exhuast thrush turbos with h pipe and turbinesComment
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Strange. Haven't seen any before 1988 with that setup. reasonably easy to tell one way or the other. If its not integrated, it has a black box mounted next to the ECM under the dash.86 Lincoln Town Car (Galactica).
5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley
91 Lincoln Mark VII LSC grandpa spec white and cranberry
1984 Lincoln Continental TurboDiesel - rolls coal
Originally posted by phayzer5
I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers
Everything looks like voodoo if you don't understand how it worksComment
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From the info I am getting from OldFuelinjection.com. On the 86-88 Crown Vic/GM The VSS+ goes in on pin 3 and the VSS- on Pin 6. It is supposedly used only during full throttle acceleration, and deceleration for the cannister purge solenoid function. My Ford fuel injection book diagram shows some sort of connection coming from the VSS to the cruise control Amp then to the Thermactor solenoids. By the way, I changed mine, and it didn't make a bit of difference. Good luckComment
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Yes but their information is a bit skewed. The 86 and 87 do not have a vehicle speed sensor input. How do I know this? Because both my original and replacement 86 harness did not have wires in pins 3 and 6. Oldfuelinjection.com also says that there is a MAF Lincoln Mark VII. This is non existant from the factory...Comment
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tis trueOriginally posted by 86VickyLX View Post
eec has pins and ability but no wires to them. pretty much all the sensor does is hold the speedo gear.Give a man a fish and he will be fed for a day. Teach a man to fish and he will promptly forget that he once did not know, and proceed to call anyone who asks, a n00b and flame them on the boards for being stupid.Comment
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