Ongoing power cutting out problem

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Check the MAP sensor on the inlet manifold. They get clagged up from the EGR and can give false pressure readings to the ECU. If it tells the ECU the turbo pressure is too high (which might explain why it only happens on full throttle when towing) the ECU will switch to limp mode and give the symptoms you describe. I take it you have not tried to turn the wick up on the turbo?

Take the sensor out and soak it in oven cleaner for a few minutes. Clean it out with some petrol or paraffin and make sure its dry before reinstalling. A new sensor is not expensive if you dont want to get dirty.
 
The MAP sensor is something that I've never even looked at. I will get it taken out today and have a look at it though. Could that also make the temp gauge jump around? I'm guessing that all sensors are on the wiring harness and could get false signals?
It is remapped (only to about 150hp) but it had this problem before that was done.
 
sorry mate, i dont remember wich where it was (t-piece) i memorized it could be black pipe from the filter on drivers side in your country. about 50cm long thing with a t piece valve something.

i asked my friend and it didnt make the cauge rising thing like yours, but other symptons was.
 
have you any signs of insulation missing on any wiring allowing the circuit to earth as that could cause temp gauge to shout up
 
johnlad said:
have you any signs of insulation missing on any wiring allowing the circuit to earth as that could cause temp gauge to shout up
Click to expand...

Nothing that I can see, and I can just about predict when it's going to happen now. I can do 1000 miles and nothing, then 5 miles towing and it happens.

A bit of an update, I cleaned the MAP sensor as suggested. I wouldn't say it was caked but it was dirty. Cleaned it up and there is a definate change to the 'misfire whilst coasting' problem. This really got me thinking about the MAP, so I have fitted a boost guage. At the moment it's just onto the waste gate actuator until I get a fitting for the inlet manifold (on order). When under load it's showing 1.5 bar! (21.7 psi) So I'm thinking that when towing i'm probably over boosting:eek:
The question is, can I fool the ECU into thinking it isn't over boosting or do I need to adjust it? If adjustment is the way forward, am I right in thinking that lengthening the actuator rod should bring the pressure down?:confused:
 
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Is the waste gate fully operational, it hasn't partially seized?
 
accywingy said:
Nothing that I can see, and I can just about predict when it's going to happen now. I can do 1000 miles and nothing, then 5 miles towing and it happens.

A bit of an update, I cleaned the MAP sensor as suggested. I wouldn't say it was caked but it was dirty. Cleaned it up and there is a definate change to the 'misfire whilst coasting' problem. This really got me thinking about the MAP, so I have fitted a boost guage. At the moment it's just onto the waste gate actuator until I get a fitting for the inlet manifold (on order). When under load it's showing 1.5 bar! (21.7 psi) So I'm thinking that when towing i'm probably over boosting:eek:
The question is, can I fool the ECU into thinking it isn't over boosting or do I need to adjust it? If adjustment is the way forward, am I right in thinking that lengthening the actuator rod should bring the pressure down?:confused:
Click to expand...

the ecu can be fooled to allow more boost, bell auto's sell a box that fits on the wiring near the ecu

eBay - The UK's Online Marketplace

like this one
 
The temperature gauge is dynamic, as on most modern cars, that means it will not move unless it overheats, just as it moves very quickly to the middle when starting up.
I suggest it is the head gasket... is there any oil in the water? Do you have to top up the reservoir?
 
accywingy said:
Nothing that I can see, and I can just about predict when it's going to happen now. I can do 1000 miles and nothing, then 5 miles towing and it happens.

A bit of an update, I cleaned the MAP sensor as suggested. I wouldn't say it was caked but it was dirty. Cleaned it up and there is a definate change to the 'misfire whilst coasting' problem. This really got me thinking about the MAP, so I have fitted a boost guage. At the moment it's just onto the waste gate actuator until I get a fitting for the inlet manifold (on order). When under load it's showing 1.5 bar! (21.7 psi) So I'm thinking that when towing i'm probably over boosting:eek:
The question is, can I fool the ECU into thinking it isn't over boosting or do I need to adjust it? If adjustment is the way forward, am I right in thinking that lengthening the actuator rod should bring the pressure down?:confused:
Click to expand...
Yep sounds like overboost as you will be loading the engine whilst towing and using more throttle to maintain speed. ECU will switch to limp mode until you restart the engine. I'd lay money that your ECU error log is full of overboost events.

Lengthen the turbo wastegate actuator rod by about five complete turns on the nut and you should be about right. This opens the wastegate earlier and limits the max boost. You can get away with about 1.2 bar (trial and error) at the turbo as the intercooler seems to drop a few psi at the manifold. Dont turn the rod or it can damage the diaphragm. Take the rod off the turbo and adjust the nut before reconnecting. While you have the rod disconnected make sure the wastegate lever operates with very little resistance. It should flap about at will.

You could buy a gadget to fool the ECU but why not make sure that this is really the problem first. You can always dial the turbo back up later on. TD5 Alive sell such a gizmo and I have one on mine. Dont know whats inside it though.
 
Sorry I forgot to update this after the weekend. It turned out that the Turbo gauge that I bought was faulty :( I swapped it for a standard air pressure gauge and i'm running around 16 psi under load. It did it's little trick today when I had a small trailer on and wasn't hard on the power. Turbo pressure stayed steady and the Tenp guage shot into the red for 1 second as always. This is really beging to frustrate me now to say the lease!!

A few months ago I changed the temp sensor that's on the top radiator hose housing. Is this the only temp sensor on the engine that would affect the temp gauge??
I'm beginning to wonder if there is another one somewhere else.

I'm fitting a new MAP sensor and thermostat tomorrow if my local main dealer get their finger out!
 
The MAP and inlet temp sensors feed into the ECU to modify fuelling but do not have a direct effect on the temp gauge reading. The temp gauge is not directly connected to the water temp sensor but is controlled by the ECU which is why it does not fluctuate like an analogue gauge. The gauge will appear stationary between a range of temperatures only rising towards the hot end when the ECU thinks its limits have been exceeded.
 
andlover said:
hey shifty1962, can u post a picture of that? and it is reliable?
Click to expand...
Could post a picture but its just a smalll black box with three wires going in one side (earth, +ve, and MAP signal) and one to the ECU (modified MAP signal). Its sealed shut so I dont want to break it open and find out whats inside it. As for reliability its never played up in three years of use. I'm assuming it halves the signal or some such magic to fool the ECU into thinking the boost is lower than it really is.

http://www.alivetuning.com/Booster.html
 
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Just a thought have you checked loom for rubbing through- an easy check.
Maybe something is intermittently shorting out. I have had similar and fuses still intact
 
Latest update on this and it aint looking good:(
First 100 miles on the way up with no troubles, then it was back with a vengeance!
Same thing as always, the only visible symptom is the erratic temp gauge, but this time i've got a boost gauge on too for chance it's overboosting. The boost gauge drops as the temp gauge goes up :(, and with a new MAP sensor on i'm happy that the ECU is getting the same signals I am. On a happy note this means I can stick my clock back in cos i'm missing it:D

Anyway, the temp did seem to act a but different on this trip, it did seem to allow itself to get above the normal 'problem temp' when under load without cutting out (new thermostat fitted last week) so again i'm happy that all is well there. I was thinking it may be overheating so will be giving everything a good flush out to make sure i'm getting good airflow.

So whilst away, i've played about and looked around for the same old things, pressurised hoses, chaffed wires (new 13 pin tow socket fitted last month so that's out of the question too andlover) Nothing unusual at all.

The journey home today however was different. We went for about 5 miles where it was playing up by the minute, and I was pulling my hair out! Mrs Nut even got a short video of the gauge jumping :confused:
During this annoying bit of the trip another annoying little thing was happening.. The N/S rear mudflap has taken to curling up on to the tyre because it's split and making a fooking annoying noise! Anyway I lost the plot, pulled into the services and whipped it off with me knife:D Whilst stopped I popped the bonnet and squeezed the top Rad hose and it's fooking solid! Stops engine, it's a bit softer but still pressurised:confused: Cap off, pressure down, set off and 5 miles of no trouble..

So the big question is, how pressurised should the coolant system be at tickover versus at revs???
Going back to Ratty's comment about the stat opening at 1500 rpm, would this make a difference? I'm begging to think this is terminal HGF but not convinced due to the lack of mixed fluids.

Apologies for the long winded post, had ****e internet for a week and my fingers won't stop:D:D
 
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