Replaced HPFP and power has reduced

[RoCZy]

Hi, in an earlier thread I got advice on replacing the HPFP, which I did. The engine seems to be running great and on light use all seems good. However, going up a hill I have noticed that the power seems to be way down and I need to drop to fourth gear, and even then there is little pulling power. I had a go trying to drive a little more aggressively and it doesn’t seem to have the guts it used to have, even for a 156bhp. Any thoughts?

 

[TheWest]

Hope I'm not going to patronise you here (certainly not my intention), but my best guess would be the adaptions. If you've been running lean for a while, the ecu will adapt to try and keep things running smoothly. This will alter things like short term fuel trim, long term fuel trim, air fuel ratios etc. based on data gathered over a period of time. This data comes from a combination of engine sensors, and driver behaviour.

That data is stored, so the car remembers what kept things running smoothly in the past, and this doesn't automatically reset when you replace a part / resolve a problem. That has to be done with an adaptions reset.

Could be something else, maybe fuel starvation, bad coils or injectors etc. Occasionally, a big problem like a failing HPFP can hide other problems that only become apparent when you start repairing things. Sudden increase in engine output could reveal a turbo problem for example (ask me how I know). But I always go with the most obvious explanation first.

You live extremely close to me. I can recommend a couple of garages in wirral if you need, but hopefully you already have somewhere in mind.

Any more questions, feel free to ask!

 

[RoCZy]

Thanks for getting back to me, and in no way were you patronising me!
I had never heard about an adaptations reset before now, but it makes sense. After suffering hard brakes I replaced the vacuum dump yesterday, as the plastic/rubber parts had disintegrated, and did an oil and filter change. I disconnected the battery whilst doing the work. I had noticed when I did the HPFP that the end of the air inlet attached to the turbo had split but thought I could get a decent sealed joint. I put it all together again and went out for a short test drive…and it felt a lot livelier. Okay, I didn’t have the long haul of the hill coming back from Llandudno but the improvement was noticeable. Could either of the things I mentioned explain this?
Even if performance had improved I don’t suppose you know that it’s running as good as it could without a reset. I’m heading to the ice hockey tonight so will have a better trial run.
Thanks again.

 

[Pedro]

Turbo could be lagging I would also check the fuel rail pressure ?

 

[TheWest]

Absolutely could be causing it. Even the cold intake has a sensor which could contribute to running problems if there's a leak in the system. But a leak on the high pressure side of the turbo system would reduce the power output to just a regular 1.6.

But yes, as Pedro said, you can check the fuel rail pressure really easily with a £5 OBD reader (and many other things).