Wont rev past 7k
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Robert
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This is the light on the ecu adam?
Yeah its on the passenger floor. Check out the link my previous reply. Its handy. Thankfully I never needed it but a mates CRX was doing wierd things and we used that to find out roughly what the problem was. We traced it back to the oil pressure sensor. Gave that a clean and the car was running sweet again.
carmadchris
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Light on the passenger floor?? The only light down there is the one on the ecu and it is not showing any error codes i have asked the guys on the crx forum but they dont have any ideas!
VTEC Inside
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I have not been on this forum in ages, so hopefully I am not too late.
The CRX will limit engine speed to 7000 RPM if the ECU thinks the coolant temperature is below 60oC. These conditions also apply when the car is doing below 20 kph. The ECU senses vehicle speed from the VSS (vehicle speed sensor). Remember that your speedo reading has got nothing to do with the ECU, they just share the same sensor.
It MAY be either a problem with your ECT (Electronic Coolant Temperature) sensor, or the VSS.
You can easily test the ECT, in the following way:
At normal engine operating temperature, the ECT resistance will be BELOW 500 ohms. (80oC = 300 ohms)
When the engine is cold / Coolant temp at approx 20oC, the ECT resistance will be around 3K Ohms.
These values are based around the ECT in my prelude but as far as I am aware, all honda ECTs are the same.
Hope this helps.
The CRX will limit engine speed to 7000 RPM if the ECU thinks the coolant temperature is below 60oC. These conditions also apply when the car is doing below 20 kph. The ECU senses vehicle speed from the VSS (vehicle speed sensor). Remember that your speedo reading has got nothing to do with the ECU, they just share the same sensor.
It MAY be either a problem with your ECT (Electronic Coolant Temperature) sensor, or the VSS.
You can easily test the ECT, in the following way:
At normal engine operating temperature, the ECT resistance will be BELOW 500 ohms. (80oC = 300 ohms)
When the engine is cold / Coolant temp at approx 20oC, the ECT resistance will be around 3K Ohms.
These values are based around the ECT in my prelude but as far as I am aware, all honda ECTs are the same.
Hope this helps.
carmadchris
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No not too late! Could you tell me where the ECT and VSS are please?
Graham
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jonny's info there will probably help more than what i'm saying but a V-tec engine needs to be at running temp b4 the vtec will work
also my m8's CRX runs on limp mode due to a sensor in the manifold being missing so make sure they are in correctly also
also my m8's CRX runs on limp mode due to a sensor in the manifold being missing so make sure they are in correctly also
carmadchris
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Yeah i am letting the car warm up properly! As far as i know all the sensors are in properly i just wanna try this ECT thing now but dont know where it is!!!
S_Gault
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yes but if the ecu thinks the engine is cold.. (due to a faulty coolant sensor) then it wont run the vtec.. same of the VSS
Steven
Steven
carmadchris
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But the vtec is defo cutting in! Should i still check the ECT??
VTEC Inside
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bollox... did not read this thread fully, sorry. :?
I agree with Steven, the VTEC won't engage if the ECU thinks the coolant temperature is below 60oC.
It sounds like you have insufficient oil pressure to the cylinder-head or the VTEC pressure switch is faulty.
The VTEC pressure switch has the job of telling the ECU that there is sufficient oil pressure present after the VTEC engages. If this is not the case, the ECU will cut fuel at 7000 RPM to prevent possible damage.
The solenoid could still be faulty or blocked (it has it's own internal filter). The ECU only checks for correct electrical resistance of the solenoid coil, so don't be fooled into thinking the solenoid is ok just because the ECU is not throwing a code.
The pressure switch is located on the VTEC solenoid, so to prevent farting around just take off the solenoid (held on by 3 bolts) and replace the entire unit from the other engine. Give the filter a wash with soap and water. It is made from a fine wire mesh, so can be re-used.
Hope this sorts your problem.
I agree with Steven, the VTEC won't engage if the ECU thinks the coolant temperature is below 60oC.
It sounds like you have insufficient oil pressure to the cylinder-head or the VTEC pressure switch is faulty.
The VTEC pressure switch has the job of telling the ECU that there is sufficient oil pressure present after the VTEC engages. If this is not the case, the ECU will cut fuel at 7000 RPM to prevent possible damage.
The solenoid could still be faulty or blocked (it has it's own internal filter). The ECU only checks for correct electrical resistance of the solenoid coil, so don't be fooled into thinking the solenoid is ok just because the ECU is not throwing a code.
The pressure switch is located on the VTEC solenoid, so to prevent farting around just take off the solenoid (held on by 3 bolts) and replace the entire unit from the other engine. Give the filter a wash with soap and water. It is made from a fine wire mesh, so can be re-used.
Hope this sorts your problem.
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