[engtmitc]

Car has been restored and fitted with wasted spark ignition and wiring loom(and presumably ECU) from a 620/820 vitesse sport post-96. Yes it's this one https://www.rover200.org.uk/forums/view ... 11&t=14138

Intermittently, it loses power such that you can only get up to 40-50 mph on the flat but if you press harder on the accelerator it slows down (as if you have lifted off the accelerator). If you stop, switch off, wait and drive off again it is OK for a while then starts again.

Car had the throttle potentiometer replaced a few months ago. I am trying to contact the previous owner to see if the wiring loom still includes the 600/800 diagnostic plug as it does not have the R8 3-pin plug from a dizzy 220 turbo. Incidentally it smokes on overrun (had a top end rebuild, the turbo was apparently a known good one but not new/recon), but I was going to take the car off the road over the winter and get that fixed next year, when I can get the car back from the garage who are scratching their heads, I don't think they have done any investigative work yet as they can't find the diagnostic plug.

I have tried resetting the stepper motor but doesn't solve it. Have trawled the RCOC faceache page (am not a full member of the forum), this forum and a R800 faceache page - suggesting various things e.g. blocked cat [see above RE smoking..? as this will damage the cat eventually?]/exhaust, fuel pump, injectors blocked, ignition coil, dirty throttle body, boost leak, CTS, crank sensor (not sure about this as I had a 214 with this, symptoms very different)...any ideas? Unless we can find the diagnostic plug!

Interestingly it seems a bit like this, including the odd buzzing noise from the back of the car (sounds like an electrical substation) but not the starting problem:
https://www.rover200.org.uk/forums/view ... =19&t=2078

[RoverRevival]

My money would be on the fuel pump.

[engtmitc]

Thanks, have relayed that to the garage who are starting from first principles fuel/spark/etc etc but I did mention to them the buzzing from the back of the car.

[engtmitc]

Garage now seeking quote for a special pipe in order to test the fuel pressure...

[RoverRevival]

Special pipe

A basic fuel pressure tester kit has the pipe in it, or should I say mine did.

[engtmitc]

Apparently they can't find a pipe/connection that fits.

[RoverRevival]

This is the one I have, so I know it has the pipe you need and not exactly expensive.

https://www.ebay.co.uk/itm/Universal-Fu ... 635-2958-0

[engtmitc]

Apparently that pack does not have the right adaptor for the car so garage now making one themselves.

[RoverRevival]

It’s currently hooked up to an 820 so I fail to see how it doesn’t have the pipe…

[engtmitc]

Edit, garage have driven the car over the weekend and don't believe its fuel pressure but I am asking them more questions based on what's being posted elsewhere. Garage said fuel pressure is OK when the fault occurs.

When the fault is not happening it doesn't seem to lack sufficient boost, when it is occurring it doesn't seem like boost cut which is like a sharp misfire I understand?