Having problems with my car. When driving after engine warmed up and very little throttle and only at :confused: approx 2000rpm get what i think is a bad misfire which causes the car to judder. When checking ecu get a code 34 (Det sensor) only. I have then reset the ecu and left car to idle recheck the ecu and get code 55. Take the car for a drive and as soon as the car misfires recheck the ecu and code 34. Is it possible for the det sensor to cause this type of misfire (judder) when failing or is it more like ptu failing (series 1 ptu) . I have been through all the connectors and have replaced the injector harness ( which made the engine run smoother ) but are a bit stumped with this. Any advice greatly recieved

Hi,

 

Code 34 is the det sensor circuit, in no way would it cause your misfire. As you've said could be the PTU, double check the connectors are clean and fully seated :)

 

 

Vijay

I have actually seen cases where this happens. Not exactly sure why, even had it on my car at one point. To see if the code 34 is giving the problem, disconnect the det sensor and bridge the ecu loom side with a 1 Meg Ohm resistor. Usual cost about 7p so no biggie. However, do this AT YOUR OWN RISK as you are then removing the ability of the ecu to protect the engine against detonation. Only proper fix is replacement of the sensor but thats a fairly major task.

I have decided to go with trying the resistor and fitting it tonight.This will a least rule the knock sensor out if the problem.

i had my car at thor this weekend and was told that it was detin. am i rite in reading that if i get a code 34 on the ecu then the car is detonating and if i dont get the code the sensor could be knacked

code 34 is the det sensor circuit, i.e the sensor itself and the wiring. It's got nothing to do with if you've actually got detting.

 

Vijay

I had a code 34 when i got my zed

the manual said change the plugs

i changed them and two coil packs

its been fine since

Have now fitted the resistor and taken the car for a drive, plenty of power but still getting slight judder about 2000rpm when using very little trottle. On rechecking the ecu after driving code 55 which was expected. (The Knock sensor checked out at 0.568M ohm ) Next port of call may be new spark plugs and / or ptu but still have problem Knock sensor to deal with.

sorry but ecu error code 34 is the det sensor circuit, can't see how it's got anything to do with the plugs or coilpacks. http://www.300zx.co.uk/cgi-bin/manual.cgi?list=efec&dir=&config=&refresh=&direction=forward&scale=0&cycle=off&slide=51&design=default&total=190

 

Vijay

It was in the big phone book size manual(martin at PPS has one)

which said code 34 det sensor: plug change needed

dont want to fall out over it tho.

Cookie, one area to check is the left hand connector on the PTU. This can cause problems with bad connections etc. Sometimes it will only happen at specific loads/rpm as the engine moves on its mounts. The problem seems to be that the loom doubles back on itself out of the back of the connector causing the pins etc to flex. Also check the coil pack connectors.

 

 

Code 34:

 

http://www.300zx.co.uk/cgi-bin/manual.cgi?list=efec&dir=&config=&refresh=&direction=forward&scale=0&cycle=off&slide=51&design=default&total=190

 

Replace harness and or sensor ;) Nowhere does it mention plugs. What you're refering to is if you are getting detonation, NOT if you get a det sensor error ;)

Cadpaul, nothing to fall out over bud :)

 

Vijay

Have already cleaned all the connectors ptu ( the left hand side was slightly corroded ) and the coil pack connectors were all okay. Do not have time tonight to check the theory of the bend in the wiring loom but will have a go at this by trying to move the ptu postion slightly if this is possible.

 

Cheers