Hi

 

I was hoping Murt or Pintovit would come back with a solution to the problem which seems to be the same as the one I have.

 

http://www.300zx.co.uk/forums/showthread.php?t=120527

 

Basically the the throttle fails to respond and the car judders like you're in too low a gear but doesn't stall when you put the clutch in. If at low speeds you have to pull over aas the car slows so much.

 

It happens at any gear and any speed or revs.

 

I've had it happen at 30mph and on the motorway at 70mph (well that's the limit isn't it!).But it only happens once in any one journey, either 2 miles home from the shops or 150 miles back from Swindon just before Christmas . Once it has cleared everythings fine.

 

Suggestions really welcome, Thanks

 

Andy.

The first thing I would do (as I had a simular issue a few weeks ago) is to disconnect the plug to the MAF.

This will put it in get me home mode (and limit the engine to 2,500 rpm) this will either confirm MAF going or that it is OK.

 

ps. all knowledge in the above statement kindly passed to me by Jeff at Zedworld :bow:

 

next time I will not sit at the side of a motorway for 2 hours and wait for the AA :nana2:

do you know what would limit the engine to 4k rpm?

Most likely causes are MAF or PTU failure.

 

MAF symptoms vary as the ECU gets conflicting information about Air intake, and total failure will result in a rpm limit. If when the problem develops, try disconnecting the MAF connector to see if the engine runs smoother. It will be limited to 2500rpm but is a simple way to find out if the MAF is at fault.

 

PTU failure will cause either Individual or multiple cylinder missfires, and faults can develop as intermittent at first, getting worse overtime.

 

The early style PTU ( 89-94) is well renowned for failure and was even recalled by Nissan in the U.S. A replacement version is available, usually referred to as a "S2 PTU". You can usually pick up a 2nd hand S1 PTU for less than 30pounds, and the S2 version goes for around 120 pounds new.

 

The symptoms can also develop from poor electrical connections at the MAF, CAS, PTU, Injectors and Coilpacks. These should all be checked and any corrosion cleaned away.

Edited February 20, 201016 yr by Yowser

well said matey :)

Had same happen on one of my Zs, PTU was breaking down, bit worrying when it happens, worth changing it to see.

 

Tony