no speedometer, HELP!!!
Thread Starter
Racer
Joined: Dec 2001
Posts: 429
Likes: 0
From: austin texas
NEED MAJOR HELP! no speedo amungst other problems!!!!
UPDATE:
Problem escalated! now i cant even start my car!! all the info is listed below thanks for your help=)
about a month ago my speedometer started acting funny. i would be crusing on the highway, the mph reading will go down while i am still going the same speed. in other words ill be cruising at 80 mph at 35 rpm and after a while it will say im going 50mph at 35rpm. well about the same time my preformance in my went WAY DOWN.. like school busses moving faster than me down. so me and kenfusion did a big tune up including:
New fuel pump (85 and up model)
fuel filter
Distributer cap and Rotor
pulgs and wires
air filter
right the next day the module in my distruter went out so i replaced it with a cheapy from autozone (i have taylor wires, super coil, and high preformance module in the mail)
the preformance went up but it is still lacking!
so any suggestions on the lack of power and messed up speedometer?
BTW- its an 84 with a 4+3
Thanks!
matt smith
[Modified by MattS4313, 12:28 AM 1/11/2003]
Problem escalated! now i cant even start my car!! all the info is listed below thanks for your help=)
about a month ago my speedometer started acting funny. i would be crusing on the highway, the mph reading will go down while i am still going the same speed. in other words ill be cruising at 80 mph at 35 rpm and after a while it will say im going 50mph at 35rpm. well about the same time my preformance in my went WAY DOWN.. like school busses moving faster than me down. so me and kenfusion did a big tune up including:
New fuel pump (85 and up model)
fuel filter
Distributer cap and Rotor
pulgs and wires
air filter
right the next day the module in my distruter went out so i replaced it with a cheapy from autozone (i have taylor wires, super coil, and high preformance module in the mail)
the preformance went up but it is still lacking!
so any suggestions on the lack of power and messed up speedometer?
BTW- its an 84 with a 4+3
Thanks!
matt smith
[Modified by MattS4313, 12:28 AM 1/11/2003]
Drifting
Joined: Dec 2002
Posts: 1,861
Likes: 4
From: Houston TX
Re: no speedometer, HELP!!! (MattS4313)
Well, I would say that it might just be the digital dash coming to bite you, but if you noticed a signicant power loss at the same time, you might be losing the ECM
Thread Starter
Racer
Joined: Dec 2001
Posts: 429
Likes: 0
From: austin texas
Re: no speedometer, HELP!!! (CorvetteZ51Racer)
my car is completly flipping out now! when i got off work today every time i started it the revs would bounce and then it would die.. after about threes times i just held the gas constant and put it into gear.. the revs where bouncing back and forth everytime i put it in neutral... HELP PLEASE!!!
Race Director
Joined: Mar 1999
Posts: 12,571
Likes: 237
From: Bartlett Illinois
Re: no speedometer, HELP!!! (MattS4313)
I think your VSS is bad. I am not sure how the VSS is wired on the 84.. but the 89 was set-up to run from the VSS to the dash (4K ppm), then converted to 2k Ppm and sent to the ECM. I woudl guess on the 84 it would be close to the same..
Thread Starter
Racer
Joined: Dec 2001
Posts: 429
Likes: 0
From: austin texas
Re: no speedometer, HELP!!! (-=Jeff=-)
Ill check into that.. but i have bigger worries right now! the car wont even start.. Thanks for yout help.
[Modified by MattS4313, 12:30 AM 1/11/2003]
[Modified by MattS4313, 12:30 AM 1/11/2003]
Instructor
Joined: Apr 2002
Posts: 199
Likes: 0
From: Austin TX
HELP!!! (MattS4313)
Hey guys we could use some advise on this one.
here it goes:Matt's vette was running poorly. No pickup, intermittant speedometer issue, code 15 for bad coolant fan relay. He needed a major tune-up anyhow so we tackled the basics and upgraded his stock 84 fuel pump to the 85 + at the same time.
The vette still was lacking power and the speedometer issue was still present. I'm thinking the speedometer is the VSS sensor going bad. (I had the winadlt software running and it matched the incorrect readout).
His distribute module went bad and he replaced it. The vette is running agin, but, now the idle is revving, lagging and then dying. It is not throwing any codes so it will be tough to troubleshoot...
any ideas???
here it goes:Matt's vette was running poorly. No pickup, intermittant speedometer issue, code 15 for bad coolant fan relay. He needed a major tune-up anyhow so we tackled the basics and upgraded his stock 84 fuel pump to the 85 + at the same time.
The vette still was lacking power and the speedometer issue was still present. I'm thinking the speedometer is the VSS sensor going bad. (I had the winadlt software running and it matched the incorrect readout).
His distribute module went bad and he replaced it. The vette is running agin, but, now the idle is revving, lagging and then dying. It is not throwing any codes so it will be tough to troubleshoot...
any ideas???
Le Mans Master
Joined: Jan 2002
Posts: 5,320
Likes: 4
From: Kyle TX (Because Mojo Made me fill it in)
Re: HELP!!! (MattS4313)
Matt,
Did Ken say he hooked you up to a datalogging program? If he did, what were the readings? Checked for a bad ground? Checked the ESC? Do you have a second ECM to test?
Did Ken say he hooked you up to a datalogging program? If he did, what were the readings? Checked for a bad ground? Checked the ESC? Do you have a second ECM to test?
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Burning Brakes
Joined: Feb 2000
Posts: 927
Likes: 0
From: Saginaw TX
Re: HELP!!! (kenfusion)
According to my Fuel Injection book the VSS can impact cooling fan operation. VSS is located at the very rear of the transmission on the drivers side. In my ignorance of such things, 85up fuel pumps are compatible with the TBI (crossfire) system?? Good Luck
Instructor
Joined: Apr 2002
Posts: 199
Likes: 0
From: Austin TX
Re: HELP!!! (MattS4313)
Quick update:
We figured out and fixed at least one of the issues tonight. The pickup coil had gone bad and had much to do with the not starting issue. Now we need to chase down what is acting like a major vacuum leak. Had to retard the timing to get it down to 1 to 1.2 k...
Matt is going to start looking for a vacuum leak; do you thyink we are headed down the right path? Any other ideas? Could a bad IAC cause this?
Many thanks to everyone for ytheir help so far
Ken (part-time Dick Tracy)
We figured out and fixed at least one of the issues tonight. The pickup coil had gone bad and had much to do with the not starting issue. Now we need to chase down what is acting like a major vacuum leak. Had to retard the timing to get it down to 1 to 1.2 k...
Matt is going to start looking for a vacuum leak; do you thyink we are headed down the right path? Any other ideas? Could a bad IAC cause this?
Many thanks to everyone for ytheir help so far
Ken (part-time Dick Tracy)
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: NEED MAJOR HELP! no speedo amungst other problems!!!! (MattS4313)
It has to be the computer. I've had my dash completely flip out before, the tach just froze, all my gauges went to zero including the speedo. The service engine light came on along with every other light on the DIC. It still ran but it ran like crap. Anything more than about 1/4 throttle and it woudl stumble bad. It did this to me several times, I replaced the ECM and it's never done it again.
