Z32 Timing Issue

zrated · Post by **zrated** » Tue Sep 30, 2008 3:36 pm

Hi Guys,

I've got an issue with a Z32 TT Manual.... When I hold the car at light throttle it hesitates and as you can see by the log, the timing is going crazy!

The timing goes from about 60 to -9 and all in between. This problem I've never faced before... It will only do it at light/steady throttle position. If I stab the throttle it will rev up and down without a problem...

The TPS is set properly (0.5v @ idle) and the base timing has been checked/adjusted.

I suspect that the timing belt might be out, or the CAS is stuffed....???

Any suggestions?

zrated · Post by **zrated** » Tue Sep 30, 2008 7:51 pm

anyone?

Eric · Post by **Eric** » Tue Sep 30, 2008 9:48 pm

does this car have a 16 bit ECU ?
..in that case this timing behaviour is normal at idle.

you could try resetting the closed throttle switch setting in the ecu (disconnect the seperate connector from the TPS for 5 seconds with the engine running)

-Eric

zrated · Post by **zrated** » Tue Sep 30, 2008 10:11 pm

Eric wrote:does this car have a 16 bit ECU ?
..in that case this timing behaviour is normal at idle.

you could try resetting the closed throttle switch setting in the ecu (disconnect the seperate connector from the TPS for 5 seconds with the engine running)

-Eric

yep, done that... but i don't think it's normal for the timing to fluctuate that much while the car is cruising/light throttle (not just at idle).

It's a 16bit, yeah.. that's a stock Z32 pre 93 model isn't it?

Eric · Post by **Eric** » Tue Sep 30, 2008 10:32 pm

>> It's a 16bit, yeah.. that's a stock Z32 pre 93 model isn't it?

pre 93/94 are 8-bit (eprom type ECU's)
later ECU's are 16 bit

if you have the 8-bit ecu, the timing behaviour in the graphs you posted isn't normal.
In that case the CAS is the first suspect, but your rpm signal looks normal.

have you tried resyncing the maps in the Nistune board ?

zrated · Post by **zrated** » Tue Sep 30, 2008 11:09 pm

Eric wrote:>> It's a 16bit, yeah.. that's a stock Z32 pre 93 model isn't it?

pre 93/94 are 8-bit (eprom type ECU's)
later ECU's are 16 bit

if you have the 8-bit ecu, the timing behaviour in the graphs you posted isn't normal.
In that case the CAS is the first suspect, but your rpm signal looks normal.

have you tried resyncing the maps in the Nistune board ?

My bad... yes it's an 8 bit ECU.

No it's definitely not normal and yes, I've tried resyncing the maps, etc. Still no luck. I really this there is something wrong outside of the ECU (ie CAS or timing). The car has just recently been rebuilt so I gather that the customer may have installed the timing belt incorrectly or maybe the CAS is just faulty.