Thread: Help with my td5 fuel pressure test video ? Engine Stopping

Check for oil in the harness plugs to engine ECU the red one
may have oil passing from injector harness via engine loom to
the plug if oil is bad the ECU can get damaged with oil topside fault
will show.

Originally Posted by ScotsD2

Check for oil in the harness plugs to engine ECU the red one
may have oil passing from injector harness via engine loom to
the plug if oil is bad the ECU can get damaged with oil topside fault
will show.

yeah, ive previously replaced the loom several months back, and checked the ecu plugs and opened up the ecu, as it was idling rough.

unfortunately that fault code in 99% of cases means that you need another(good) ECU or get this one repaired... with this fault the ECU actually cuts the feed to the injectors that's why your engine is cutting out...i had it myself that's how i know

did you measure the pressure at the FPR? cos normally there it must stay under pressure if the ignition is off

take off the cover of the main relay(R9 engine bay) and watch it when the symptom occures...if it opens when the engine stops get another ECU

pressure measured at input of fpr and does appear to drop off rapidly compared with another video online.

That's a good idea to check the relay like that. I suspect the ecu too, but the mechanic thinks the fuel pump.

Thanks for the input. As you can get knock off fuel pumps cheap enough these days we are trying that as my current one is noisy. And if that doesn't work will try ecu.

you must fit the gauge instead of the fuel temp sensor in the FPR...then the pressure must not drop instantly... as long as the pump delivers 4 bar in action imo it's good enough, it's normal for the pressure to drop on the pump's HP outlet when the pump stops

Ok so is there some sort of non return valve in there that keeps it pressurized. ?

on later modells there is a non return valve in the filter head's rear inner pipe...but the system is built so as to keep the pressure steady in the rail when the ignition is off that's why the measurement is relevant where the sensor is, watch carefully the scheme and you'll figure it out

i just ordered an ecu off ebay MSB101192 ,should match my 01 auto td5. will try putting the pressure sensor in the temp sensor to see if any difference. do you know if i need any diagnostics to install the ecu, or can i just swap it over ?