hi i have been having intermittant hesitation on my z for a while , it generally occurs between 1-2k rpm and i have been able to catch a spike on datascan

 

as you can see from the screen grab it goes loopy!

 

i have a duel mapped ecu and was going to illiminate the crossover switch just incase this is at fault and is trying to switch maps while driving.

 

any advice on anything else it could be?

 

i was in traffic doing approx 8-15 mph

 

 

Edited September 20, 201015 yr by hellraiser

here is the dial view of it

 

 

mines back now.

mines back now.

 

cool, is it running right now?

yeh jeff had it and it for a week and it sounds smooth as silk now, gotta wait till pay day to tax it. then its all systems go again cant wait. plus the whole episode means ive got a clear space behind the gates to hide it outta the way now :D

yeh jeff had it and it for a week and it sounds smooth as silk now, gotta wait till pay day to tax it. then its all systems go again cant wait. plus the whole episode means ive got a clear space behind the gates to hide it outta the way now :D

 

excellent news fella :)

cant anybody offfer any advice? :(

not sure whether this will be relevant to your problem or not but i was getting hesitation on pullaway but not noticeable at any other time . jefftt checked it over and told me the o2 sensors were weak / playing up and sending dodgy signals . he disconnected them and the hesitation problem stopped .

duty cycle :ohmy: :surrender:

duty cycle, rpm,timing all spiking, if you work it out i went from about 8 mph to 78 mph and back ibn two seconds according to that chart lmao

happy days... i wouldnt bother getting a tt with performance like that! sorry i cant offer anything constructive bud :(

:helpsmilie:The dials look the same as the underfloor heating system to me , and all the pressers are uneven so you have a leak .

Looks like the RPM signal is causing the ECU to try and correct all other parameters (except the speed). I would guess a CAS or ECU fault. Probably ECU given the high erratic speed reading too

Just spotted the battery volts - 10.2. Some sort of power supply issue to the ECU or internal fault perhaps

i agree... id start with a straight swap for a known good ecu

thanks for all the ideas guys, i will go through and try a few things.

first thing is first to permanently switch to my performance map and see if it spikes.

Is it possible that if a faulty speed sensor momentarily shows up the wrong speed could the speed limiter be cutting in (NA SWB=japanese import =112mph?), 78.4 mph = 125.9888 km/h, would this not pull the power back as its showing the car travelling too fast when in fact you are doing 15 mph or less?

Is it possible that if a faulty speed sensor momentarily shows up the wrong speed could the speed limiter be cutting in (NA SWB=japanese import =112mph?), 78.4 mph = 125.9888 km/h, would this not pull the power back as its showing the car travelling too fast when in fact you are doing 15 mph or less?

 

the thing is the rpm is spiking too it was showing 25k rpm LOL

the real speedo cluster doesnt miss a beat and is very accurate with no jumpyness at all.

 

will add it to the list of things to check tho. im sure i have a spare speed sensor somewhere.

the thing is the rpm is spiking too it was showing 25k rpm LOL

the real speedo cluster doesnt miss a beat and is very accurate with no jumpyness at all.

 

will add it to the list of things to check tho. im sure i have a spare speed sensor somewhere.

 

Me working with Commercials, generally the speed sensor supplys the speedo, the speedo supplies like the engine ecu with an output for speed limiter etc so am wondering if its the same as with the zed, its just something I get with the commercials, frickin nightmare to find at times but just a guess more than anything.

 

Cheers John

the thing is the rpm is spiking too it was showing 25k rpm

268,812 RPM in the first picture !!!!

Lol quite impressive! I would say faulty ecu/map Showing closed as well so you wernt even on the gas!

could be a faulty CAS/connector/wiring.

 

RPM-signals comes from there.

 

(Duty cycle spike is also caused by the RPM spike)

spare set of hands here if needed, dont know much but happy to do as told and learn :D

spare set of hands here if needed, dont know much but happy to do as told and learn :D

 

thanks for the offer mate :)

 

i will keep that in mind

could be a faulty CAS/connector/wiring.

 

RPM-signals comes from there.

 

(Duty cycle spike is also caused by the RPM spike)

 

your not the first person to mention that to me :) definitely a consideration as i have a spare.

 

cheers