Jump to content
View in the app

A better way to browse. Learn more.

300ZX Owners Club

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

OK, since before the THOR RR day my Z has been running seriously rich. I now need help to diagnose the problem.

 

Firstly, when the engine is cold/warm there is a very minor missfire.

 

Secondly, when the engine has got to normal temp (middle of the gauge) the missfire is worst.

 

Thirdly, On stock boost, the missfire is pretty bad, it gets worst higher up the rev range.

 

Lastly, If i turn up the boost eg 12 - 14.5psi the higher the boost the worst the missfire. At 15psi it wont even rev by 5000rpm.

 

Today, Me and a mate changed the plugs and put a smithy's fuel line kit on. I didn't do this to cure the problem it's just to say that it's not the plugs.

 

John Dixon is coming over to hopefully sort my problem out at the end of May. I don't need the car for a while yet as most of you know i'm a bit busted up at the mo.

 

All i'm hoping for is to make John's life a little easier when he comes over.

 

Also, if anyone has a ConZult who lives nearby there will be as much tea/beer/food as you can have.

 

Cheers

 

Rich;)

Featured Replies

PTU. Clean the contacts or even better is there anyone near you you can swap one over with?

 

Vijay

OK Vijay, I'll do that mate,

 

I'll be at the Midlands meet on 2nd of May if anyone fancys swopping there's over.

 

Oi. Matty, give me ya PTU.......LOL

 

Cheers Bud

 

Rich:D

Excuse my major dumbness, but if the PTU was shot would it make my Z run extreamly rich??

 

Ta

 

Rich :confused:

Excuse my major dumbness, but if the PTU was shot would it make my Z run extreamly rich??

 

Ta

 

Rich :confused:

 

 

 

If the PTU was shot it wouldnt run at all. If the PTU was not getting a good connection it would cause a weak spark or cause it not to spark at all.

Good point, it might look like it was running rich as the fuel when it didn't fire would pass into the exhaust and possibly burn up a bit in there.

.....or could be a failing coilpack ;) I've got hundreds if you need one LOL. You need to find which cylinder is missing - disconnect each coil pack in turn until the revs don't drop, that will be the problem cylinder...

 

CheerZ,

 

Andy

just a silly one, I had the same thing and it was only cured when i changed the WHOLE wiring loom including censors. might need to give them a clean.

.....or could be a failing coilpack ;) I've got hundreds if you need one LOL. You need to find which cylinder is missing - disconnect each coil pack in turn until the revs don't drop, that will be the problem cylinder...

 

CheerZ,

 

Andy

Ta Andy,

 

On inspection of the coil pack when i changed the plugs yesterday on a couple at least there was a small amount of cracking where indicated in pic.

 

Do you think this could be anything to do with it?

Quite possible tbh mate!!! Try putting some known good ones on and give that a wirl ;)

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

Recently Browsing 0

  • No registered users viewing this page.

Important Information

Terms of Use

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.