No rpm on speedo and car idles high??
#1
No rpm on speedo and car idles high??
Hi guys,
Searched through all the forums and can't find where to go next....
Basically car hasn't been used much for a year then I started it got mot done, serviced it and everything seemed fine.
Couple of days later the engine rpm on the speedo stopped working and the idle speed went high, about 1500-2000 I'd say, and seems to climb as the car gets warm..
Sweeping gauges work fine at key on.... and everything else on the dash works.
I figured a speed sensor issue but can't seem to find in the manual exactly which sensor is responsible for the tacho.
Have no light on the dash for CEL...
Any ideas lads and lassies?
Thanks!
Searched through all the forums and can't find where to go next....
Basically car hasn't been used much for a year then I started it got mot done, serviced it and everything seemed fine.
Couple of days later the engine rpm on the speedo stopped working and the idle speed went high, about 1500-2000 I'd say, and seems to climb as the car gets warm..
Sweeping gauges work fine at key on.... and everything else on the dash works.
I figured a speed sensor issue but can't seem to find in the manual exactly which sensor is responsible for the tacho.
Have no light on the dash for CEL...
Any ideas lads and lassies?
Thanks!
#4
Scooby Regular
iTrader: (4)
In the ye olde days vehicle speed was transmitted by a cable from the gearbox to the dash dials, then it changed to an electrical sensor usually mounted in place of the cable. Abs came along and now speed is calculated from the wheel sensors, but there were some cars that had abs and a seperate sensor in the t/m as well.
Might be worth checking if there is one on your car?
Might be worth checking if there is one on your car?
#5
Cheers, I bet ye old days it was easy fixs stupid issues like this, lol!
Speed sensor is on the trans, but the speedo works fine also.
It's the engine rpm I've an issue with... could be either of the two cam sensors or the crank or all three combined, or could be the signal from the ecu to the dash.....im going to check the sensors with an oscilloscope later see if I can find anything.
Keep the suggestions coming tho thanks!
Speed sensor is on the trans, but the speedo works fine also.
It's the engine rpm I've an issue with... could be either of the two cam sensors or the crank or all three combined, or could be the signal from the ecu to the dash.....im going to check the sensors with an oscilloscope later see if I can find anything.
Keep the suggestions coming tho thanks!
#7
Ok a bit further on this issue....
Checked signal from sensors, all fine.
Checked signal from ecu to dash, nothing.
Put my old original ecu in to try that and my rev gauge works fine and car idles correctly..
So looks like I have a controller issue.....what do I do with an old simtek?? Anybody know what could be wrong or more importantly anyone able to fix a broken one?
Checked signal from sensors, all fine.
Checked signal from ecu to dash, nothing.
Put my old original ecu in to try that and my rev gauge works fine and car idles correctly..
So looks like I have a controller issue.....what do I do with an old simtek?? Anybody know what could be wrong or more importantly anyone able to fix a broken one?
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#9
Scooby Regular
So that's burned out, Not sure if those would be repairable, Back in the day I done specialist repairs on computer motherboards where I could remove and replace smt chips including pads and tracks however it was all specialist equipment.
I bet those ECU's ain't cheep hopefully It can be repaired and what ever caused the issue resolved.
I bet those ECU's ain't cheep hopefully It can be repaired and what ever caused the issue resolved.