XU7 engine pinking problem

[Bob Minchin]

I am still having pinking problems when cruising and only very gentle accelerator pressure. Following advice from Mindwipe I have switched from supermarket fuel to branded, Shell Esso Texaco etc with no noticeable difference. I have also run a tankful of super unleaded through with only marginal improvement.

The ECU is reporting no errors so I am beginning to think that perhaps a sensor (MAP ??) may be sending erroneous info to the ECU but no so out of spec to be logged as an error?

Has anyone any experience of this or any ideas?

Sadly my local Pug dealers have let me down in the past to the extent I would not trust what they say nor their analytical skills.

TIA

Bob

 

[Mindwipe (7)]

I am still having pinking problems when cruising and only very gentle accelerator pressure. Following advice from Mindwipe I have switched from supermarket fuel to branded, Shell Esso Texaco etc with no noticeable difference. I have also run a tankful of super unleaded through with only marginal improvement.

The ECU is reporting no errors so I am beginning to think that perhaps a sensor (MAP ??) may be sending erroneous info to the ECU but no so out of spec to be logged as an error? remove and check the vacuum hose to the map sensor

also check the wiring to the crank position sensor as erroneous readings from that will cause problems last ditch is to have the ignition retarded slightlu using either diag200 or tep 92

 

[Yuting Wan]

I have had two 306 with XU7 fitted. Apparrently the factory setting for the timing requires high octane fuel (>95). With low octane fuel, it will pink. Another problem I had was the oxygen sensor that may have a kinked wire and partially broken away. I have had my sensor changed twice... Your are right some Peugeot dealers are hopeless, the other day they mistakenly thought the airbag problem was caused by connector and just cut the connector out, replaced with soldered joint and heat shrink tube. A second shop visit found out the problem was caused by a faulty communication unit. Now if you want to remove the front seat, you need to cut the cable again...
Y.W.

 

[Mindwipe (7)]

the wiring under the seats IS the weak point and they were CORRECT to solder it regardless of further faults this action was well worth taking

 

[Yuting Wan]

The wiring underneath the front seats are a bit messy, four or five connectors under each front seat. What I am afraid of is that if you have too many this kind of non factory mods, after a while, it will become un-traceable even if you have some repair manuals...I did have a good look at every connector under the seats before sending to Peugeot dealer for repair, they all seemed to tbe OK.. Well, I probably have gone to far on this as we are supposed to talk about pinking....

 

[Bob Minchin]

mindwipe wrote:

also check the wiring to the crank position sensor as erroneous readings from that will cause problems last ditch is to have the ignition retarded slightlu using either diag200 or tep 92

Thanks Jeff,
I'll take a look tomorrow weather permitting. Do you know the best way to test the MAP sensor?. Is it a resistor that varies according to vacuum? Is the cranck sensor just a coil or is there some electronics inside to give a digital ouput?

TIA

Bob

 

[Mindwipe (7)]

mindwipe wrote:

Thanks Jeff,
I'll take a look tomorrow weather permitting. Do you know the best way to test the MAP sensor?. Is it a resistor that varies according to vacuum? Is the cranck sensor just a coil or is there some electronics inside to give a digital ouput?

TIA

Bob

map sensor is usually a 5 v input and between .5v to 4.9 v output peizo

type sensor
crank sensor is 2 wire ac genertor type so look for ac output....you could remove it clean off all the crap and refit it if its adjustable type(you'll know if it is)then set the gap by glueing a piece of card to it and pushing it flush (i use the box off an oil filter) DIAG2000(TEP92) can retard ignition in .5 deg increments just remember that if you deal with a pug dealer always ask for the master tech and mention that your brother in leeds(thats me wink) is one too...won't hurt

 

[Bob Minchin]

mindwipe wrote:

type sensor
crank sensor is 2 wire ac genertor type so look for ac output....you could remove it clean off all the crap and refit it if its adjustable type(you'll know if it is)then set the gap by glueing a piece of card to it and pushing it flush (i use the box off an oil filter) DIAG2000(TEP92) can retard ignition in .5 deg increments just remember that if you deal with a pug dealer always ask for the master tech and mention that your brother in leeds(thats me wink) is one too...won't hurt

Thanks (brother!) Jeff.

I have located the MAP sensor and it has a good stable 5vsupply. At tickover, the output voltage is 1.16v and gunning the throttle it peaks at about 4 volts. Gentle use of the throttle to soomthly raise the revs through to 4000 rpm. and the voltage falls into the range 0.75 to 0.9 volts. At a steady 4000 (engine not loaded) it sits around 0.8v.

Would you say that this is about normal behaviour?

As for the Crank sensor, I have failed to find one. Haynes says it is on the front face of the transmission housing but other than the reversing light switch, I can't find anything electrical in that area at all. Please can you give me a clue where I should be looking? I assume it is sensing the flywheel position?

Tia

Bob

 

[Mindwipe (7)]

mindwipe wrote:
extent

I have located the MAP sensor and it has a good stable 5vsupply. At tickover, the output voltage is 1.16v and gunning the throttle it peaks at about 4 volts. Gentle use of the throttle to soomthly raise the revs through to 4000 rpm. and the voltage falls into the range 0.75 to 0.9 volts. At a steady 4000 (engine not loaded) it sits around 0.8v.

Would you say that this is about normal behaviour?

yes looks ok from here

As for the Crank sensor, I have failed to find one. Haynes says it is on the front face of the transmission housing but other than the reversing light switch, I can't find anything electrical in that area at all. Please can you give me a clue where I should be looking? I assume it is sensing the flywheel position?

it will be tucked out of site there are 2 possiblities on your engine down the back next to the speedo sensor(rarely) and at the top right next to where the bell housing meets the block

 

[Bob Minchin]

mindwipe wrote:

yes looks ok from here
it will be tucked out of site there are 2 possiblities on your engine down the back next to the speedo sensor(rarely) and at the top right next to where the bell housing meets the block

Thanks Jeff,

When I was looing around the engien this morning, immediately under the thermostat housing there were two cables with connectors held on a metal bracket sticking out to the right (from the front of the car).. Going by feel as I could not see anything, the rigth hand connector had nothing connected to it (maybe the knock sensor as used by the XU10 engine?) I could not see where the lefthand one went at all. Maybe this is the Crank sensor? I would appear to get at it I would have to remove the air intake pipe that comes from the grille and goes into the 'dirty' side of the air filter.
Am I getting warm?

Thanks for your help as ever Jeff, It is much appreciated.

Bob

 

[Mindwipe (7)]

mindwipe wrote:
glueing

Thanks Jeff,

When I was looing around the engien this morning, immediately under the thermostat housing there were two cables with connectors held on a metal bracket sticking out to the right (from the front of the car).. Going by feel as I could not see anything, the rigth hand connector had nothing connected to it (maybe the knock sensor as used by the XU10 engine?) I could not see where the lefthand one went at all. Maybe this is the Crank sensor? I would appear to get at it I would have to remove the air intake pipe that comes from the grille and goes into the 'dirty' side of the air filter.
Am I getting warm?

Thanks for your help as ever Jeff, It is much appreciated.

Bob

temp sensor connectors bob

bear in mind that the sensor will be fitted to meet the flywheel if in doubt just follow it all the way round still tink an adjustment with diag2000 will be needed though (or upgrade to a 406 ;-)