Please help? I'm having a few issues with my 300zx TT. Where do I start!

 

1. I’m having a problem where the speedo drops out and the steering gets heavy and it doesn’t change gear, etc. I replaced the Speed sensor but it still happens (Mainly when it’s wet). At times it’s like it when I start the car and I have to have Hold switched on to get it to change into second gear. I connected OBD Tech Scan to the car whilst driving and noticed that when the speedo drops out the ECU is still reading the correct speed?? :confused: . I spoke to Zed World (Got it booked in for March) and they suggested it may be the instrumental panel? Any other ideas?

 

2. Problems starting the car (Most of the time). When I first start it up it revs up and starts to judder, the juddering get worse then it cuts out, if I then restart it strait after it usually starts fine? When it is juddering if I step on the accelerator the car just cuts out?

 

3. The car is using tones of petrol! On the weekend I put £30 in the tank drove to Amphill and back which is around a 50 - 55 mile round trip and the tank was almost empty on my return. I was booting it on the return trip, but still 30 quids worth???

 

Other Info which may help... I have had OBD Tech Scan hooked up and noticed my bank1s (Fuel section) are running RICH... My o2 Sensor is bouncing between 0 and 1000 every second or so... also I have a hole in my exhaust which I hope to get patched soon.

 

Would it be any use to record data with OBD Tech Scan and post it up (I have no idea how to read the data)??

 

Any help on the above would be much appreciated. Thanks

I could probably do £30's worth of VPower in about 42 miles on high boost (1 bar) :/

 

You running standard boost?

Please help? I'm having a few issues with my 300zx TT. Where do I start!

 

1. I’m having a problem where the speedo drops out and the steering gets heavy and it doesn’t change gear, etc. I replaced the Speed sensor but it still happens (Mainly when it’s wet). At times it’s like it when I start the car and I have to have Hold switched on to get it to change into second gear. I connected OBD Tech Scan to the car whilst driving and noticed that when the speedo drops out the ECU is still reading the correct speed?? :confused: . I spoke to Zed World (Got it booked in for March) and they suggested it may be the instrumental panel? Any other ideas?

 

A fault with the instument panel wouldnt cause the steering to become heavy and stop the 'box changing gear!

 

2. Problems starting the car (Most of the time). When I first start it up it revs up and starts to judder, the juddering get worse then it cuts out, if I then restart it strait after it usually starts fine? When it is juddering if I step on the accelerator the car just cuts out?

 

Is it misfiring? it sounds like its running very rich to me. What are the condition of the spark plugs like? Have you checked to see if they are all sparking? more info please mate!

 

 

Diagnosing faults online isnt the easiest thing in the world to do, so the more info the better. If you get chance, take a small video of the engine running and post it up, this will aid your chances in someone being able to diagnose any faults

 

Third and finally, welcome to the club

 

Nick

I could probably do £30's worth of VPower in about 42 miles on high boost (1 bar) :/

 

You running standard boost?

 

I only ever put high octane petrol in.

 

Yeah, the boost is at standard, the only thing that is not standard in the car is the air filter.

A fault with the instument panel wouldnt cause the steering to become heavy and stop the 'box changing gear!

 

Could it be a dodgy connection somewhere in a cable? This problem is worse in the wet.

 

Is it misfiring? it sounds like its running very rich to me. What are the condition of the spark plugs like? Have you checked to see if they are all sparking? more info please mate!

 

 

Diagnosing faults online isnt the easiest thing in the world to do, so the more info the better. If you get chance, take a small video of the engine running and post it up, this will aid your chances in someone being able to diagnose any faults

 

Nick

 

No it doesnt seem to be misfiring, once it gets going it runs really smooth. The Cozult Like application I use says it is running rich, when i start it all you can smell is petrol.

The spark plugs have been replaced in the last couple of thousand miles, but i have not checked them for a while. I have also shutdown each cylinder one at a time in Tech Scan and it makes a huge difference with every one.

 

I will try and get a video done today or tomorrow, Ill post it up ASAP.

 

 

Third and finally, welcome to the club

 

Nick

 

Thank you. :)

Please help? I'm having a few issues with my 300zx TT. Where do I start!

 

1. I’m having a problem where the speedo drops out and the steering gets heavy and it doesn’t change gear, etc. I replaced the Speed sensor but it still happens (Mainly when it’s wet). At times it’s like it when I start the car and I have to have Hold switched on to get it to change into second gear. I connected OBD Tech Scan to the car whilst driving and noticed that when the speedo drops out the ECU is still reading the correct speed?? :confused: . I spoke to Zed World (Got it booked in for March) and they suggested it may be the instrumental panel? Any other ideas?

 

Is your car JDM? if it is some of the de-limiters/converters are nasty and cause this.

 

Otherwise I had exactly same problem, changed the clocks and its alright now.

 

2. Problems starting the car (Most of the time). When I first start it up it revs up and starts to judder, the juddering get worse then it cuts out, if I then restart it strait after it usually starts fine? When it is juddering if I step on the accelerator the car just cuts out?

 

Probably the coil packs and connectors they get shot due to age and the searing underbonnet temperatures of a Z

 

3. The car is using tones of petrol! On the weekend I put £30 in the tank drove to Amphill and back which is around a 50 - 55 mile round trip and the tank was almost empty on my return. I was booting it on the return trip, but still 30 quids worth???

 

Welcome to the club this is quite 'normal'

 

Other Info which may help... I have had OBD Tech Scan hooked up and noticed my bank1s (Fuel section) are running RICH... My o2 Sensor is bouncing between 0 and 1000 every second or so... also I have a hole in my exhaust which I hope to get patched soon.

 

New sensors needed for sure

Get the zorst replaced dude

 

Would it be any use to record data with OBD Tech Scan and post it up (I have no idea how to read the data)??

 

Any help on the above would be much appreciated. Thanks

 

An 'almost-a-supercar' like the Z has almost-a-supercar running costs. When you buy a Z you should look at the bank balance and lifestyle of the person who sold it to you. I suggest you only buy from two types:-

 

Did they look like they would have sold their shirt to keep the Z in fine fettle.... or.... have it as a plaything next to their other cars / toys that are all looked properly?

 

If not you are now typically (at this stage of a cars life) either fixing all that has been neglected in the past or enjoying the fruits of many years of TLC lavished on the car. Sadly most Z's have been through a period with owners thinking 'not much more to by than my corsa' and then scrimping on everything. Luckily this 'cleansing' of the market will only last a few more years and the good Z's will be left.........Hope yours is one of them

To start with :-

 

Check the water temp sensor is working correctly

Check both O2 sensors are working - the one you described as 'bouncing all over the place' is correct

Check the TPS is set correctly

Check for air leaks

An 'almost-a-supercar' like the Z has almost-a-supercar running costs. When you buy a Z you should look at the bank balance and lifestyle of the person who sold it to you. I suggest you only buy from two types:-

 

Did they look like they would have sold their shirt to keep the Z in fine fettle.... or.... have it as a plaything next to their other cars / toys that are all looked properly?

 

If not you are now typically (at this stage of a cars life) either fixing all that has been neglected in the past or enjoying the fruits of many years of TLC lavished on the car. Sadly most Z's have been through a period with owners thinking 'not much more to by than my corsa' and then scrimping on everything. Luckily this 'cleansing' of the market will only last a few more years and the good Z's will be left.........Hope yours is one of them

 

So do I! The car is in pretty good condition, I bought it off a friend who I know looked after it but before that I have no idea as it was an import. It's only done around 45, 000 miles. I don't mind putting the money in to get it back on track, but in the same respect I would not like to pay for a garage to sort something out that I may be able to resolve myself.

1) More than likely dry joints on the speedo circuit board

 

2) & 3) Check the ECU temp sender connector for corrosion - what water temp is showing on the OBD? Also reset TPS voltage and then base idle.

 

O2 sensors should be bouncing, its a closed loop feedback system :)

To start with :-

 

Check the water temp sensor is working correctly

Check both O2 sensors are working - the one you described as 'bouncing all over the place' is correct

Check the TPS is set correctly

Check for air leaks

 

I'm pretty sure the water temp sensor is okay, I get data back from that in conzult, I'll double check that.

How do I check the TPS is set correctly? I cleaned the throttle bodies and checked and cleaned all the connection around them, but that is about as close as i have go to that.

Where could I have an air leak, and again how can I check for those?

TPS setting http://www.300zx.co.uk/forums/showthread.php?t=83683

Base Idle http://www.300zx.co.uk/forums/showthread.php?t=83687

 

What water temp does the OBD read at operating temp?

1) More than likely dry joints on the speedo circuit board

 

2) & 3) Check the ECU temp sender connector for corrosion - what water temp is showing on the OBD? Also reset TPS voltage and then base idle.

 

O2 sensors should be bouncing, its a closed loop feedback system :)

 

Where is the speedo circuit board? I'll check it out.

 

ECU Temp sensor? is that the one with the yellow connection at the front of the engine? Thats fine, I check that one all the time. I think OBD is showing about 150F. How do I reset the TPS voltage and base idle?

Thank you everyone for the responces so far. :)

If its showing 150 it is reading too low. Should be more like 185F - 85C. Make sure you take it for a drive though before checking it...

Oh and speedo circuit board is on the back of the speedo. You need to remove the dash cluster, then remove the speedo unit from that. Reflow every soldered joint you can see :)

Oh and speedo circuit board is on the back of the speedo. You need to remove the dash cluster, then remove the speedo unit from that. Reflow every soldered joint you can see :)

Okay, Ill try and do that this weekend. Thanks.

 

Just off subject, where do I sign up for the 2008 ZED Meet?

Add your name to the last page of this thread :)

 

http://www.300zx.co.uk/forums/showthread.php?t=100457

Add your name to the last page of this thread :)

 

http://www.300zx.co.uk/forums/showthread.php?t=100457

 

Done

That's excellent and a very generous offer!!!!

 

Thank you!