Congratulations to vtecmec for winning May/June's Lude Of The Month, with his DIY Turbo BB1 build.

>>> Click Here For Profile <<<

Image

VTEC Intermittent Part 2

Engine/Gearbox questions and discussion
EddieMunster
Posts: 186
Joined: Mon Apr 30, 2018 8:31 pm
My Generation: 5G
Has thanked: 14 times
Been thanked: 24 times

VTEC Intermittent Part 2

Post by EddieMunster » Thu Aug 27, 2020 11:31 am

So, further to the initial problems.....

The VTEC works, but only as the engine is about to hit "normal temperature"; once it's at normal temperature, VTEC stops engaging, when it's cold, it won't engage (as you'd expect). So, the issue is pointing towards the VTEC sensor, but which one is responsible for this function?
5g 2.2 Motegi in Blue.

Scott560
Posts: 1320
Joined: Sat Aug 31, 2013 4:44 pm
My Generation: 5G
Location: Didcot
Has thanked: 19 times
Been thanked: 214 times

VTEC Intermittent Part 2

Post by Scott560 » Thu Aug 27, 2020 3:35 pm

It will be one of the temperature sensors most likely. Have you got the workshop manual?
'00 UKDM 2.2VTI H22a8
'21 'e' Advance

EddieMunster
Posts: 186
Joined: Mon Apr 30, 2018 8:31 pm
My Generation: 5G
Has thanked: 14 times
Been thanked: 24 times

VTEC Intermittent Part 2

Post by EddieMunster » Thu Aug 27, 2020 4:27 pm

Scott560 wrote:
Thu Aug 27, 2020 3:35 pm
It will be one of the temperature sensors most likely. Have you got the workshop manual?
Not for the 5g, no.
5g 2.2 Motegi in Blue.

Scott560
Posts: 1320
Joined: Sat Aug 31, 2013 4:44 pm
My Generation: 5G
Location: Didcot
Has thanked: 19 times
Been thanked: 214 times

VTEC Intermittent Part 2

Post by Scott560 » Thu Aug 27, 2020 5:00 pm

PM'd
'00 UKDM 2.2VTI H22a8
'21 'e' Advance

Scott560
Posts: 1320
Joined: Sat Aug 31, 2013 4:44 pm
My Generation: 5G
Location: Didcot
Has thanked: 19 times
Been thanked: 214 times

VTEC Intermittent Part 2

Post by Scott560 » Thu Aug 27, 2020 5:46 pm

Page 297 (section 11-65) gives the chart for checking the ECT (Engine coolant temperature), which is the 2 pin connector sensor in the thermostat housing. The single wire is for the cluster gauge only.

Rather than warming the car up with the sensor disconnected, I would do the reverse. Drive the car until it's warm and fault apparent (just around the block, no need to rag it, otherwise it'll take an age to cool down).

Once you know you have the fault condition , come home, open the bonnet, disconnect the 2 pin plug, then measure the resistance of the sensor.

It should match up with the graph. Very low resistance when the engine is hot (100ohms for 120C, 400ohms for 80c). Resistance will rise steadily as the car cools down, all the way to over 1000ohms (500ohm being 60 degrees C, which i think is too cold for VTEC).

Give that a go, and see what results you get from the sensor - It may explain the strange running when cold, because the ecu doesn't know the true operating temperature.
'00 UKDM 2.2VTI H22a8
'21 'e' Advance

EddieMunster
Posts: 186
Joined: Mon Apr 30, 2018 8:31 pm
My Generation: 5G
Has thanked: 14 times
Been thanked: 24 times

VTEC Intermittent Part 2

Post by EddieMunster » Thu Aug 27, 2020 5:54 pm

Scott560 wrote:
Thu Aug 27, 2020 5:46 pm
Page 297 (section 11-65) gives the chart for checking the ECT (Engine coolant temperature), which is the 2 pin connector sensor in the thermostat housing. The single wire is for the cluster gauge only.
Wouldn't the temp gauge on the dash cluster be wrong too, if it's the same sensor?
5g 2.2 Motegi in Blue.

Scott560
Posts: 1320
Joined: Sat Aug 31, 2013 4:44 pm
My Generation: 5G
Location: Didcot
Has thanked: 19 times
Been thanked: 214 times

VTEC Intermittent Part 2

Post by Scott560 » Thu Aug 27, 2020 6:05 pm

Sorry if i wasn't clear - there are 2 sensors in the thermostat housing. One is a single pin (with a bum droppings black sleeve cover thingy) - that feeds the gauge cluster.

The 2 pin one is for the ECU only, so the gauge is no indicator of what the engine thinks the temperature is based on the 2 pin sensor readout.
'00 UKDM 2.2VTI H22a8
'21 'e' Advance

EddieMunster
Posts: 186
Joined: Mon Apr 30, 2018 8:31 pm
My Generation: 5G
Has thanked: 14 times
Been thanked: 24 times

VTEC Intermittent Part 2

Post by EddieMunster » Thu Aug 27, 2020 6:13 pm

Ah right...... I'll probably just get a new 2-pin sensor, I can at least cross that job off my list. I've had to spend £1k on it, in bits alone, to sort out a car that the previous forum member was 100%, and that's not included addressing the bodywork either.
5g 2.2 Motegi in Blue.

Scott560
Posts: 1320
Joined: Sat Aug 31, 2013 4:44 pm
My Generation: 5G
Location: Didcot
Has thanked: 19 times
Been thanked: 214 times

VTEC Intermittent Part 2

Post by Scott560 » Thu Aug 27, 2020 7:25 pm

I wouldn't go buying sensors willy-nilly based on what some stranger said on the internet, it's just a hunch on my part without even having seen the car, or you having performed any test.

I just went into the garage, got my spare sensor, hooked it up to the multimeter and checked it. 2.2k ohms indoor temperature, dropping quickly to ~400ohms when i wiggled a lighter under it for 6 seconds.

If you would care to do the test, I'm happy to send you the sensor for free as mentioned in my PM.
'00 UKDM 2.2VTI H22a8
'21 'e' Advance

EddieMunster
Posts: 186
Joined: Mon Apr 30, 2018 8:31 pm
My Generation: 5G
Has thanked: 14 times
Been thanked: 24 times

VTEC Intermittent Part 2

Post by EddieMunster » Thu Aug 27, 2020 8:28 pm

Scott560 wrote:
Thu Aug 27, 2020 7:25 pm
I wouldn't go buying sensors willy-nilly based on what some stranger said on the internet
Haha, it was you that suggested it! :D

I have to balance time vs cost, I want to have it sorted without any further delay and everything I replace is just something else that's not going to go wrong in the future.
5g 2.2 Motegi in Blue.

Post Reply

Return to “Engine / GearBox”