i went for a little drive and the first time the car started fine, it started immediatly.

after my drive i went and do something, came back and the car just wont start.

the enigine turned but wouldnt fire up.

 

lately it feels like the car was going to stall in low rpm but it never did.

i recently replaced the ptu on the car.

it feels like when the engine is getting warm he just wont start.

i had someone pick me up and after driving by a half hour later i wanted to trie it again.

 

the car started without a single problem. just like normal

 

anyone a idea what this might be

 

300zx tt 1993

PTU generally, did you replace it with a secondhand one? upgrade to a series 2 ptu( nothing to do with the series of the car) just an upgrade. You will not get the overheat problem associated with the series 1.

Check Crank Angle sensor its under the right hand Boost pipe on the side of the cam cover! If it becomes loose this maybe a cause of your Non starting.

Alternativly it does again sound like PTU, Check to see if you are getting a spark from the spark plugs as well. Try and isolate where the problem is as it could be any number of things!

It was a brand new ptu that I replaced it with.

Also the ptu was about 50 percent smaller than the original.

Could it be that?

http://tech.aus300zx.com/pturepair/Image8.jpg

 

Show series 1 and 2 together

http://tech.aus300zx.com/pturepair/Image8.jpg

 

Show series 1 and 2 together

 

Which is which in the image? Only ever seen what is on my car which doesn't help me :confused:

i would assume series 2 is the smaller black box, looks more modern

Series 1 has the fins

http://tech.aus300zx.com/pturepair/Image8.jpg

 

Show series 1 and 2 together

and the one with fins ,on the left is?

Series 1 has the fins

 

Guess I could be on borrowed time then...scary how many spares you need to carry for a zed!

and the one with fins ,on the left is?

 

The alloy one on the left is series 1.

i replaced it with the right one (newer and smaller)

Check the input plugs to the ptu, they have to be tight and locked together tight, i had a problem with the fitting the new ptu, with running until i made sure the connections were in there tight.