What else are Sunday afternoons for ?
Discussion
When using my S2 last week, it started to cut out on me at junctions due to the very low idle speed, before the tick over valve cuts in. This happened up to 6 times on a journey, very annoying. The tick over has always been very low, but as this in controlled by the ECU so what can you do. 
The problem is that the tick over valve does not operate until the car is almost stationary, when it sits at a steady 800 rpm. Before the valve kicks in, the revs are very low, and it some times cut out. This only happens when the engine is warm, as I suspect the ECU keeps the revs up until the engine has warmed up.
So I checked the bible and Haynes Granada manual, and decided to set about cleaning the two air flow meters, throttle plates, and air bypass tick over valve. It was not too bad, I used small amounts of aerosol carb cleaner and it is very clean now. The only gunk was on the temp sensor on the lower AFM. I put it all back together and it ran OK. So I pack my tools away, put the roof down, and jumped in to go for a ride to test it, and it would not start - Arrggghhh.
I could not hear the fuel pump prime the system when I switched on the ignition, so I went under the car the check that it was getting power. I pulled the connector apart, and it fell to bits - oops. (Arrgghh) So fixed that with a con bloc (Bodge but it works), and tried again, but no volts getting to it.
So under the dash, in a mass of wiring (TVR original mess + 2 immobilisers + alarm ..... you get the idea). If I bypassed the yellow fuel pump relay, the pump ran, but this is controlled by the ECU
and there was no power getting to the relay coil.
After 3 hours of fiddling and tracing wires, I tracked it to the injection relay (Brown) that switches power to the whole engine/ECU system. Bypassed that and it fired up - was I glad or what.....
Especially as the TVR was at the top of the drive,
blocking in my other car. I opened up the injection relay and it looked fine, so put it back in and the car runs fine now.
And I appear to have cured the cutting out issue
) as it ran fine on the way to work yesterday.
I also checked the throttle pot resistance and operation while I was under the bonnet. It seemed fine to me. If nothing else, it was a good learning experience.
It may be running better now as I disconnected the ECU wiring loom for about 1 hour while I was tracing the fault. The ECU may have reset to default factory mapping, so the problem my come back gradually as it learns and adapts to the car. I will wait and see.
Sorry for the Essay, but what else are Sundays for?
Glad to be running again
Pete
The problem is that the tick over valve does not operate until the car is almost stationary, when it sits at a steady 800 rpm. Before the valve kicks in, the revs are very low, and it some times cut out. This only happens when the engine is warm, as I suspect the ECU keeps the revs up until the engine has warmed up.
So I checked the bible and Haynes Granada manual, and decided to set about cleaning the two air flow meters, throttle plates, and air bypass tick over valve. It was not too bad, I used small amounts of aerosol carb cleaner and it is very clean now. The only gunk was on the temp sensor on the lower AFM. I put it all back together and it ran OK. So I pack my tools away, put the roof down, and jumped in to go for a ride to test it, and it would not start - Arrggghhh.
I could not hear the fuel pump prime the system when I switched on the ignition, so I went under the car the check that it was getting power. I pulled the connector apart, and it fell to bits - oops. (Arrgghh) So fixed that with a con bloc (Bodge but it works), and tried again, but no volts getting to it.
So under the dash, in a mass of wiring (TVR original mess + 2 immobilisers + alarm ..... you get the idea). If I bypassed the yellow fuel pump relay, the pump ran, but this is controlled by the ECU
and there was no power getting to the relay coil. After 3 hours of fiddling and tracing wires, I tracked it to the injection relay (Brown) that switches power to the whole engine/ECU system. Bypassed that and it fired up - was I glad or what.....
Especially as the TVR was at the top of the drive, blocking in my other car. I opened up the injection relay and it looked fine, so put it back in and the car runs fine now.
And I appear to have cured the cutting out issue
) as it ran fine on the way to work yesterday. I also checked the throttle pot resistance and operation while I was under the bonnet. It seemed fine to me. If nothing else, it was a good learning experience.
It may be running better now as I disconnected the ECU wiring loom for about 1 hour while I was tracing the fault. The ECU may have reset to default factory mapping, so the problem my come back gradually as it learns and adapts to the car. I will wait and see.
Sorry for the Essay, but what else are Sundays for?
Glad to be running again
Pete
Gassing Station | S Series | Top of Page | What's New | My Stuff