td4 goes limp

Can anyone point me in the right direction with an engine management light coming on at 1800 rpm and the car going into limp mode. I've changed turbo hoses, fuel rail sender & loom, tightened every pin & connection I can find, checked turbo linkage, vacuum hoses, changed HP pump sender/valve, replaced fuel pump & filter, cleaned & disabled EGR, checked turbo lift. I've disconnected the exhaust before the cat and run the motor to try and see if the exhaust had collapsed-this gives a missfire and strong smell of unburnt fuel. Ive disconnected the MAF which runs the motor at 1200rpm and no more. In neutral the motor revs to 5000rpm with no hesitation but on the road it'll fall over at 30-40mph and accelarating over 1800-2000rpm. Sorry to go on but if someone is kind enough to read this and respond I thought as much info as poss would help. Also checked injectors on my Lynx and carried out leakoff. Cheers

You seem to have covered most of the common / obvious causes.

Have you had the fault codes read / checked?

Sounds like a possible boost pressure fault, does the car smoke when revved ?

Maybe along the lines of a split intercooler or faulty boost pressure sensor.

There are many on here with more experience than I on Hippo's maybe someone else has a better idea of what the fault is.

Thanks for the tips. I am getting p1190 on the fault codes which led me to replace the fuel rail and HP pump units. This let the car drive for a little further before the eng management lamp came on. There's no excessive smoke when revving or driving. I'll try to locate the boost pressure sender as you've mentioned. I dont think there's any damage to the intercooler, but I've a mind to fitting a pipe to bypass the cooler just to prove it. Thanks once again as I'm really getting stumped by this!

I have no personal experience of this but several people on here have had faults with corrosion on the connection for the fuel rail pressure sensor connector causing intermittent / fluctuating readings and resulting in running issues.

I would check this connection is clean & tight.

take the fuel pressure wiring off and spray the ends and the fuel pressure sensor with switch cleaner it could be that ,

Thanks everyone, I've replaced the fuel rail sender loom and then took it off, sprayed & cleaned the ecu terminals (all the ecu plugs removed and checked) and even tightened the tiny spade connectors. On removal of the inlet manifold I've found the sender-the one opposite the EGR- full of old coked up oil. Is this the boost pressure sender you've mentioned? I'll try and clean that and may be able to test with a pump to see if there's a reading.

Have you changed the HP fuel pump or just the regulator ? Sounds exactly what I was getting and it was the HP pump in the end

Did you say you have replaced the low pressure fuel pump & filter in the rear wheel arch?

'Morning folks, I've just changed the HP pump regulator as I was thinking that as the motor maintains top revs in neutral, then it must be supplying sufficient fuel? This is the second fuel pump and filter (from left hand rear wheel arch) as the first replacement (no names mentioned) was really noisy. I'm hoping the fault isn't th HP pump as I should imagine the owner will scrap it. That'll be a shame as these are good little cars when they're going well.

Bignose said:

Thanks everyone, I've replaced the fuel rail sender loom and then took it off, sprayed & cleaned the ecu terminals (all the ecu plugs removed and checked) and even tightened the tiny spade connectors. On removal of the inlet manifold I've found the sender-the one opposite the EGR- full of old coked up oil. Is this the boost pressure sender you've mentioned? I'll try and clean that and may be able to test with a pump to see if there's a reading.

Click to expand...

I think he was talking about this below.....gives similar symptoms to your fault.
http://www.landyzone.co.uk/lz/f9/td4-lack-power-70mph-fixed-77147.html

Cheers, mjrimmer. That's such an easy test to carry out that it's worth trying just to see what occurs. I've removed the manifold boost sender at the moment-has anyone got the readings for the three pins?

I had something similar but it was the MAP (manifold absolute pressure sensor) on the LH end of the inlet manifold:-

http://www.landyzone.co.uk/lz/f9/all-very-odd-246450.html

http://www.landyzone.co.uk/lz/f9/where-do-i-find-map-sensor-249291.html

Hi Bignose,
Could you please tell me what resolved your problem? I'm having a similar problem with my 2003 TD4.

Many Thanks,
Hiru

hiruss said:

Hi Bignose,
Could you please tell me what resolved your problem? I'm having a similar problem with my 2003 TD4.

Many Thanks,
Hiru

Click to expand...

Looks like Bignose isn't on this forum that much and hasn't posted for a couple of months.