New engine, same old problem

[Cloggy Saint]

If I need to stop and start the car a few times in succession when the engine is hot i get all kinds of trouble. Throttle response is terrible, the car judders and mis-fires and it's generally rough. I had exactly the same problem when the car was a 2.0 and was hoping that with a new engine, loom, ecu etc the problem would end up in the skip with the b20! What could be causing this?

[BenHar]

Did you reuse anything from the old engine?

Ben

[Cloggy Saint]

Nothing.

[BenHar]

The symptoms sound like leaking injectors.

Check the fuel rail pressure.

Ben

[Cloggy Saint]

The injectors were refurbed by injectortune before fitting but I'll check it out.

edit: How do I check it out?

[BenHar]

<Brianmoore> Get a £10 pressure gauge from ebay and connect it in line to monitor the pressure.</Brianmoore>

If the pressure drops rapidly after turning the engine off either the pressure regulator or injectors are leaking.

Ben

[Cloggy Saint]

But if this was the case wouldn't the problem be constant?

[BenHar]

If the injectors are leaking down after you stop then when you restart with the engine hot there will be extra fuel in the manifold making it run rich for a short time.

Ben

[daimlerman]

Whilst fuel starvation is a good call,I'm wondering if the issue could be as simple as a corroded earth strap...

I would replace the engine/chassis earth strap and polish(with a wire brush!)the mounting on the chassis leg.
Bear in mind that the ECU functions by receiving odd voltage signals from several engine-mounted sensors,so a dodgy earth will confuse these.

[Cloggy Saint]

Ah, that makes sense, thanks.