V reg clio engine problem

[FATBOY]

my mates girlfriend has got her V reg 1.3 / 1.4??? clio in the garage at the moment as there having problems with starting the car... the garage cannot diagnose whats wrong???

so far theyve found out the following.. my mates words not mine. " supply voltage to manifold pressure sensor from ecu should be 5 volts but is reading 1.8/2.2 volts" ??????

thats what the garage have told them??

[stan]

I take its a managment fault, and thats from the diagnostic scanner?

basically theres a voltage drop to that sensor. Usually (i'll check Autodata in a minute), the sensors are in circuits with each other, so althought its the MAP sensor which is being flagged up, its likely that its another sensor on the same circuit causing the low voltage.

Failing that they need to check supply voltage to the ecu and/or the voltage/function of the managment relay.

see if you can find out what they have or havnt checked, and what the syptoms are if any, or if its just non-start.

i'll check autodata....

[stan]

need to know if its 16v or 8v, and if its defo a 1.4, and not a 1.2

[FATBOY]

ok mate just trying to get hold of him now

[stan]

right it seems they will be similar...

TPS, coolant sensor and air temp are all on the same circuit.

SO

first they should check supply voltage to ecu (may be dodgey earth).

if its all ok there, they need to check the sensors above. Then check at ecu multiplug to see if your getting the correct voltage outputs, and 5v to that circuit.

[richy]

as pointed out need to know which engine is it and if 8v or 16v too, some of the 16v's have problems with the engine loom from the ecu rubbing through on a metal casing causing all sorts of problems!

they do work on a 5v circuit fed via the ecu, as craig pointed out they need to check the ecu has correct before/after ignition +12v feeds and good earths, then check the wiring from ecu to the sensor incase of corrosion etc causing high resistance, if they have someone who knows about electrics i would of thought they could check it easy enough by either volt dropping/resistance/continuity tests

btw thats if its def the supply circuit to the map sensor

[FATBOY]

ok lads cheers for the help! will get the rest of info from my mate when i speak to him tomorrow.