JX Engine cold start/ running issue

[stesully]

My 1.6TD JX Engine is taking ages to start & then when it does it runs ok but then intermittently flat spots. It then sits idling, refusing to rev. It then revs for a bit then flatspots and sits idlling again. Doesn’t do it once warmed up. Had a recon fuel pump fitted about 5 months ago Any suggestions?

[davidoft1]

Sounds like air in the system, but check the heater plugs too

[stesully]

How do I sort out air in the system?

[ajsimmo]

Could be input shaft seal letting air in over time whilst standing. When you stop the engine (hot) there is a slight depression inside the pump body (this is what draws fuel from the filter). As the pump and fuel cools it contracts and can draw in more tiny air bubbles through the seal. The bubbles all join together at the top, and this air lock prevents the pump pressurising the fuel sufficiently to deliver it to the injectors.
This would explain the poor starting and flat response until air is purged. It seems like it's better when hot, but it's probably as much a function of time, not just heat. In other words, it just happens to be getting warmer whilst it's purging the air. If you let it cool for half an hour/1hr/2hrs is it as bad, or fine?

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[stesully]

Yea, it does seem to be as I pull away from standing or sit idling for a while.

[stesully]

Is the seal in the fuel filter?

[ajsimmo]

No, the one in the front of the pump on the drive shaft. It's a pump off job to change it, so do everything possible to check it's not pulling air in somewhere else first!

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