Odd issue: spedo doesn't work on cold start, car runs better than when it does?!
07-29-2012, 11:07 AM
#1
Odd issue: spedo doesn't work on cold start, car runs better than when it does?! Kind of hard to explain.
During a cold start, my speedometer doesn't work for the first few miles. But the car seems like it has a set if gears in it, the rpms are a lot higher during cruising.
Now, when the spedo works, my rpms drop like I just went from 373s to 273s.
Between 40-50 mph if I try to cruise the rpms jump up and down like I'm playing with the throttle. (very annoying)
Also, anything over 40 mph, if I wot, the rpms jump around like I am again playing with the throttle. Like I have a miss or am losing fuel pressure. BUT, this only happens when my spedo is working. It runs great when it doesn't work?!
Hope you guys understand the issue, it's pretty hard to explain.
During a cold start, my speedometer doesn't work for the first few miles. But the car seems like it has a set if gears in it, the rpms are a lot higher during cruising.
Now, when the spedo works, my rpms drop like I just went from 373s to 273s.
Between 40-50 mph if I try to cruise the rpms jump up and down like I'm playing with the throttle. (very annoying)
Also, anything over 40 mph, if I wot, the rpms jump around like I am again playing with the throttle. Like I have a miss or am losing fuel pressure. BUT, this only happens when my spedo is working. It runs great when it doesn't work?!
Hope you guys understand the issue, it's pretty hard to explain.
07-29-2012, 08:04 PM
#2
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Kind of hard to explain.
During a cold start, my speedometer doesn't work for the first few miles. But the car seems like it has a set if gears in it, the rpms are a lot higher during cruising.
Now, when the spedo works, my rpms drop like I just went from 373s to 273s.
Between 40-50 mph if I try to cruise the rpms jump up and down like I'm playing with the throttle. (very annoying)
Also, anything over 40 mph, if I wot, the rpms jump around like I am again playing with the throttle. Like I have a miss or am losing fuel pressure. BUT, this only happens when my spedo is working. It runs great when it doesn't work?!
Hope you guys understand the issue, it's pretty hard to explain.
During a cold start, my speedometer doesn't work for the first few miles. But the car seems like it has a set if gears in it, the rpms are a lot higher during cruising.
Now, when the spedo works, my rpms drop like I just went from 373s to 273s.
Between 40-50 mph if I try to cruise the rpms jump up and down like I'm playing with the throttle. (very annoying)
Also, anything over 40 mph, if I wot, the rpms jump around like I am again playing with the throttle. Like I have a miss or am losing fuel pressure. BUT, this only happens when my spedo is working. It runs great when it doesn't work?!
Hope you guys understand the issue, it's pretty hard to explain.
Last edited by reservoirdogs12; 07-29-2012 at 08:05 PM. Reason: Forgot something.
07-30-2012, 03:40 PM
#7
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I don't know if your '93 will throw a code for a bad VSS, but my Taurus definitely did. It would also work fine while the car was cold. I seemed to have about 10 minutes of in-town driving before it would crap out. After sitting overnight, I'd go through the same thing again.
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08-06-2012, 08:38 PM
#9
It sounds like the converter isn't locking up when the speedo isn't working. I know its a 700R4 but I still think the PCM uses the VSS to control lockup. That's why it feels like you have 3.73's when its not working and 2.73's when it does.
IMO that's the only thing that makes sense.
I have a 89 S10 blazer. My VSS stopped working a while back and my converter doesn't lock up anymore.
IMO that's the only thing that makes sense.
I have a 89 S10 blazer. My VSS stopped working a while back and my converter doesn't lock up anymore.
08-06-2012, 08:46 PM
#10
I was looking in the engine bay and I'm 95% positive my vss wire touched the header, it was burnt through a little bit. I think that might be the issue. Can I replace the wires? Is it a thick black cable like looking thing that runs along my drivers "frame rail" then down to my wheel?
09-17-2012, 07:09 PM
#14
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Yes the vss is necessary for proper shift points. You need to get codes out of all modules to decide were to start. But you also could get under the car and look at the speed sensor wiring and connection. The sensor is at the tailhousing
09-17-2012, 07:10 PM
#15
I was looking in the engine bay and I'm 95% positive my vss wire touched the header, it was burnt through a little bit. I think that might be the issue. Can I replace the wires? Is it a thick black cable like looking thing that runs along my drivers "frame rail" then down to my wheel?
Open to suggestions
