I need help - i have a late 1989 Z32 300ZX V6 Non turbo swb which seems to be under the weather a bit. It seems to have an intermitant loss of power which feels almost like a bad misfire. Once the engine is above 3000rpm it clears until i change gear and the revs are back below 3000rpm again. it seems to come and go but the engine managment light does not illuminate when it is running rough, the cat temprature light does come on if you try to drive up hills below 3000rpm when it is running rough which says to me that it must still be sending fuel into the cylinders. i have treid the obvious like plugs, fuel filter etc but nothing seems to make a difference. Any ideas ? Thanks

Might be the TPS (throttle position sensor) or the MAF (mass airflow sensor). It would be worth cleaning the wiring loom for both and seeing if it helps. The TPS can be found on the passenger side of the engine at the front of the plenam. The loom go's from the TPS down to the Crank angle sensor so give it all a good clean.

 

The MAF is down by the air filter (under the panel between the headlights) and again give the loom a good clean.

 

If your lucky cleaining the looms might just clear the fault...(if not a proper tech wizzard will be along in a bit with some other ideas...)

 

Andy

If the cat heat light is coming on, then fuel not getting burnt properly, which points to Spark. The most likely culprits are Coilpack breaking down, coilpack connector corroded, a break in the PTU harness or the PTU itself.

If the cat heat light is coming on, then fuel not getting burnt properly, which points to Spark. The most likely culprits are Coilpack breaking down, coilpack connector corroded, a break in the PTU harness or the PTU itself.

This may seem like a really stupid question but PTU is a what? also what is the best way to check the coil packs as checking all 6 sounds like a fun process

PTU=Power transistor unit.. (coil packs..) each plug has its own coil pack that receives a signal from the PTU, as for testing them someone will be along soon to help...

 

(PTU is on the fron face of the engine drivers side if that helps)