Rover v8 flapper system

Rover v8 flapper system

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Discussion

jensencars

Original Poster:

66 posts

73 months

Tuesday 13th August 2019
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Hi all
Just a technical question for all you flapper system injection techs
As I understand the system the thermotime sensor is the one nearest the front of the engine with temperature sensor for ECU just behind it, I have just changed this one as I had the black plastic type which when I tried to undo it it just spun so had to butcher it a bit, fortunately when I got the plastic bit broken off there was a slot across the top of the brass section which allowed me to use a flat piece of metal as a screwdriver to unscrew it, anyway that all went ok in the end.
Next checked my wiring and believe I have the plugs on correctly but what would happen if the thermotime plug was on the ECU temp sensor and temp sensor plug on thermotime switch does anybody know?

adam quantrill

11,538 posts

242 months

Tuesday 13th August 2019
quotequote all
When cold, the thermotime switch will be closed. Then if it's plugged into the CTS wires by mistake, the ECU will be fooled into thinking the engine is very hot.

In summertime, it might still start, but will be very lean.

jensencars

Original Poster:

66 posts

73 months

Wednesday 4th September 2019
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Hi,
Right re-set /checked everything, have been on a couple of road tests seems ok but if it’s ticking over in the garage and I blip the throttle 2-3 times it still dies as it returns to tickover, doesn’t do it if you throttle back gently is this just a characteristic of the flapper unit does anyone know? Also have metered the exhaust and I’m running at 1.6 % co someone told me they don’t like running under 3.5% but it seems to run happy enough..

mrzigazaga

18,555 posts

165 months

Wednesday 4th September 2019
quotequote all
Hi

Mine has been doing this for a while...however not sure what cured it out of this:

Originally I only had a manual radiator fan switch, I was relying on the gauge in the car before switching it on..now since I had a probe fan controller fitted it comes on way below what I was reading as 90...so running hot...the other thing was a ill fitting flame trap hose...have you checked the breather on the N/S rocker cover...should have a piece of foam that needs to be clean and a tiny hole through the brass mushroom, to remove this its best with a warmed engine and lightly tap under it with an open end small spanner...smile

It might help if you switch everything on...i:e lights fan interior fan...hazards etc once the car has warmed up to see if it stalls...if yes then put the idle up a tad on the idle adjustment screw on the plenum neck.


Hope this helps


Ziga smile

adam quantrill

11,538 posts

242 months

Wednesday 4th September 2019
quotequote all
What is your tickover RPM? ALso, have you checked your throttle butterfly gaps, and removed any crud from that area?

What about the throttle pot? Check both idle setting voltage, and also smooth voltage operation while operating the throttle by hand.

Edited by adam quantrill on Thursday 5th September 07:53

jensencars

Original Poster:

66 posts

73 months

Thursday 5th September 2019
quotequote all
Hi
Thanks for help
Yes all breathers clear, butterfly gap correct and throttle pot has a smooth sweep and meters out correctly only thing was it only went up to 3.7 volts book said 4.6 (as I recall don’t have it to hand,) but I checked a spare I have and it was the same..

jensencars

Original Poster:

66 posts

73 months

Thursday 5th September 2019
quotequote all
Sorry forgot rpm is 750

mrzigazaga

18,555 posts

165 months

Thursday 5th September 2019
quotequote all
jensencars said:
Sorry forgot rpm is 750
That's a bit low if its a 350i...need more like 950-1000 rpm..bigger engines around 850...900 rpm

jensencars

Original Poster:

66 posts

73 months

Thursday 5th September 2019
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Thanks will wind it up a bit

eesbad

1,329 posts

202 months

Thursday 5th September 2019
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jensencars said:
Hi
Thanks for help
Yes all breathers clear, butterfly gap correct and throttle pot has a smooth sweep and meters out correctly only thing was it only went up to 3.7 volts book said 4.6 (as I recall don’t have it to hand,) but I checked a spare I have and it was the same..
Normal rule of thumb is anything between 4.1 and 4.5 volts will be fine. The ECU triggers full enrichment above 3.7 volts, so above this just sets at what percentage of WOT this will kick in at.