TPS works with engine off, but no TPS signal with engine on

[jano]

Hi,

My MJLJ v3 instalation have now been running flawless for I guess around 6years. But lately I have noted that I really don't have the power as I used to have and the throttle control is horrible at low RPM.

I have spend the last couple of months trying to get my mac to connect to the MJLJ, but now it finally works.

I had an suspicion that the TPS calibration was off or the TPS was dead, but it turns out that the TPS is fine when the engine is off but once the engine is on there is very little if any signal from the TPS.

What to look for?

What do you think,, new TPS, perhaps vibration kills it. Perhaps I have a loose connection somewhere that only materializes when engine is on? Electrical noise on the signal.

How do I proceed?

br

Jan O
1968 Lotus super seven

[Alex B]

First test all connections between the TPS and the MJ. If that looks ok try how the TPS behaves when you remove it from the carb and turn it from 0% to 100% load with the engine running.

Alex