If I've been driving in traffic for a while then give it some beans it's almost like it's lost 3rd of it's power, the difference is night and day. Especially in the hot weather we've had recently. Anyone else's get this?

 

Once I'm on the motorway and the cars had a chance to cool with a bit of air through the front ic's and rAd it's back to feeling reasonably quick again. Is there anyway around this? Water temp is normal, oil temp is fine, boost levels fine, just really slow feeling and very hot in the cabin. Is this heat soak?

 

I've noticed it runs very lean during idle at about 17-18afr and 14-15afr while cruising. Would this cause too much heat?

Having the car mapped on a rolling road without proper air cooling makes me think it's going to be difficult to get a good map with good power. Is it better to map during the winter instead?

17 aft at idle suggest you might have a vac leak. Cruising at 14-15 is not a problem in and of itself, but again could be suggesting a vac leak if the map wasn't setup that way.

 

In terms of heat soak, you need to monitor your IAT to see what's going on.

17 aft at idle suggest you might have a vac leak. Cruising at 14-15 is not a problem in and of itself, but again could be suggesting a vac leak if the map wasn't setup that way.

 

In terms of heat soak, you need to monitor your IAT to see what's going on.

 

Yeah I've thought of fitting an intake air temp gauge maybe nows a good time.

Haven't done an air leak test for a while might do one 2mow. Doesn't feel like an air leak, no hesitation or spluttering runs lovely.

 

I think I just get heat soak during city driving at very low London speeds of 20mph and sitting in traffic or at the lights.

Literally after sitting in traffic for a while then giving it some it's like it's dead. Then onto the motorway for a few minutes and it's fine again power is back. Sucks :(

Jimmy, whilst I've been working on mine I found the aux/aircon fan is wired to a switch in the cabin to turn it on and off. I'm yet to find out if the ecu controlled functions of the fan have been removed (turning on with aircon and when the temp reaches 105 deg c) to make it simply on/off via the switch or not, but it's something you could look into at least

Jimmy, whilst I've been working on mine I found the aux/aircon fan is wired to a switch in the cabin to turn it on and off. I'm yet to find out if the ecu controlled functions of the fan have been removed (turning on with aircon and when the temp reaches 105 deg c) to make it simply on/off via the switch or not, but it's something you could look into at least

 

I removed my Aircon some years ago, scrapped the lot.

You could always replace the fan?

Does you clutch still bite with the same intensity or does it feel sluggish?

Does you clutch still bite with the same intensity or does it feel sluggish?

 

Feels the same? What you getting at?

Anyway just realised I have a leak from either the exhaust manifolds or the downpipe sooooo looks like it's going in the garage. Need to find someone who's knows their zeds.

If I've been driving in traffic for a while then give it some beans it's almost like it's lost 3rd of it's power, the difference is night and day. Especially in the hot weather we've had recently. Anyone else's get this?

 

Once I'm on the motorway and the cars had a chance to cool with a bit of air through the front ic's and rAd it's back to feeling reasonably quick again. Is there anyway around this? Water temp is normal, oil temp is fine, boost levels fine, just really slow feeling and very hot in the cabin. Is this heat soak?

 

I've noticed it runs very lean during idle at about 17-18afr and 14-15afr while cruising. Would this cause too much heat?

Having the car mapped on a rolling road without proper air cooling makes me think it's going to be difficult to get a good map with good power. Is it better to map during the winter instead?

 

14-15:1 AFR whilst cruising is what it should be doing. If your O2 sensors are operational, then close to 14.7:1 stoich. Where are the wideband sensor(s) located? If it's a sniffer pipe, then a reported leaner idle condition is typical.

 

The Z32 uses a MAF, which measures the mass of the airflow, which is dependent on the density of the air, which is what will change from the warmer to colder months. MAF-based systems don't require any IAT correction.

 

If it is indeed losing such a large proportion of power, it can only really be due to a reduction in boost level and/or timing. It could be that heat soak is causing knock, but need to know more info.

Noel, if it's causing knock / timing retard related, wouldn't the ecu need to be cycled ie off/on before performance returned?

Noel, if it's causing knock / timing retard related, wouldn't the ecu need to be cycled ie off/on before performance returned?

 

Typically, yes. However, some ECUs behave slightly differently to others. It is sometimes possible to switch from knock maps to normal maps on a car with a faulty knock sensor by simply switching the flag on/off in the software. Other times, the ignition does indeed need to be cycled. Additionally, many will always run off the knock maps, unless the bypass is carried out. Depending on the map, there may well be identical knock maps at any rate, or the boost solenoids may not even be present. Many variables.

 

It could be all manner of issues, it needs to be monitored properly whilst hot/cold to determine exactly how much power is being lost and why.