[Engine] 1.9D intermittent loss of power bodge

[jimbo]

    My 2004 1.9D has had an intermittent fault since I have owned it some day's it is fine and other days it plays up after a short journey. The fault is a sudden loss of power when in the mid throttle position, I suspected from the start that it may be the throttle position sensor on top of the Lucas injection pump but this part does not seem to be available. So I thought that maybe making it think I had my foot to the floor all the time might prove that that was what the faulty component was, so I removed it and cable tied it as per the picture and so far it seems to have cured it. Not sure what the long term effects of this Will be probably increased fuel consumption? But it has made driving a pleasure again. I look forward to hearing any comments regards Jamie.

[cancunia]

Interesting.
I don't know much about these engines, so am just guessing that the TPS will affect the injection timing, and maybe the fuel metering. Would be good to know how you get on with this.

[kenbw2]

Interesting.
I don't know much about these engines, so am just guessing that the TPS will affect the injection timing, and maybe the fuel metering. Would be good to know how you get on with this.

Interestingly my 1999 DW8 (not DW8) has no electronic advance, but I have that switch. In fact, my Bosch pump is from a N/A XUD9 which definitely didn't have electronic advance.

EGR maybe?

[Sol]

Is your engine braking a bit fierce with it like this? Could be idle / WOT control, though 3 wires could be either a potentiometer, or a change over switch. If it was a genuine TPS then I'd think it wouldn't like it held at full throttle position but if it's to detect whether your either pushing the pedal, or idling / coasting in gear with your foot off,, it could be an electronic throttle damper input to the pump to prevent the engine braking from feeling so strong (as diesels tend to do without damping), softening the response to a suddenly shut throttle while in gear, if you get my drift.

Older diesel's used to have a wee hydraulic damper thing on the throttle actuator to stop the pump's fuel control from slamming shut instantly when you lifted off in gear. Without it, you felt like you'd stood on the brakes when decelerating.

[jimbo]

I have checked it with an ohm meter and is definitely a potentiometer. I have to say the transformation in driving the van is amazing it is like it is on steroids before it was like a slug now it flies I was even looking for an extra gear on the motorway. The jury is still out on the fuel consumption as it is so expensive at the moment it is hard to tell. I will keep you updated as I may try a pull up resistor across the wires so that when it goes open circuit it fails to the high voltage rather then low .

[Sol]

  Must be injection stroke (injected volume) control for the pump then, Bosch units on vw vans had a similar system using a variable voltage from a moving plunger and it was common on caddy TDI's to put a switch on this, simulating full stroke and generating a lot of extra power. (A bodge btw)

The only cautionary thing I'd say then, is exhaust gas temperatures (EGT) will go a lot higher than normal with increased fuelling on diesels, and you may not see any immediate issues from this, but its generally avoided by the tuning tribe for various reasons. Have a Google on that subject and make your own mind up.

[jimbo]

an update I have been running with the cable tie fitted since the post I have had no problems but I do drive conservatively, I have covered 11000 miles in the last year. Interestingly when I had the mot recently the emissions where one of the lowest he had seen. I get between 40 - 45 MPG. When I cable tied it originally it was just to try and prove that the TPS was faulty but with the increase in power and parts not being available it remained fitted.

[Jamespworth]

I've done the same thing today and does seem to drive better however it has put my engine management light on, is that to be expected?

Will probably try to get a used one at some point but will run like this for now.

[jimbo]

no engine light on mine

[Jamespworth]

It's a strange one as it's still plugged in so I guess it shouldn't put the management light on. Perhaps I ha e a dodgy wire to it and by taking it off I've disturbed that.