Hi all, I've had my 300zx now for a few months and decided about a month ago to change the cone filter at the front as the old one was literally black and had crumpled where I guess the engine had been trying to suck air through a blocked filter. Now she has a lovely new one....but the car now seems to overfuel and drink petrol like it's going out of fashion and when I'm driving and open my window I get a smell of exhaust fumes coming in..:-( it's really frustrating. I'm thinking of cleaning the mass air flow sensor with proper cleaner for the job but any advice I'd gladly receive. I can't even go to my first meeting as it would cost the earth on fuel. Very sad. :hang:

I'd check the connection on the MAF mate, sounds like it isn't connected properly, so the ECU is just pouring fuel in. If you unplug it, the engine should die, or at the least start running differently, does that happen? Or does unplugging it do F all? If so, your MAF is not connected properly, or dead.

I posted about the smell of exhaust fumes coming in when the window is open, seems like it's a very common problem judging by how many others left comments

I think I tried unplugging the MAF twice...one time it stuttered and then carried on running of sorts and then second time it died

Maybe it just needs an ECU reset. If it's been used to struggle to breathe, then it won't really know that you have fitted a new air filter until it's been run for a little while. It's worth a try for nothing.

How do you reset the ecu? And thx for the reply..:-)

Unplug the battery for a few hours, that should do it.

In my N15 Almera, unplugging the battery, pressing the brake light (until they stopped working) and waiting 10 min used to do it. I'm sure with the Z32 ECU you'd be able to do something fancy with it.

Ok I've disconnected the battery. Give it a few hours see what happens ..:-)

Is it exhaust fumes or petrol as these cars are notorious for leaking fuel lines on the plenum which get worse as the cold weather starts due to the pipe work contracting!

I believe it's exhaust fumes...a lot of people have talked about the aerodynamics and exhaust fumes getting in via the boot area but I could check the fuel lines over the plenum

im still getting exhaust fumes in the cabin, there are 2 air vents in the rear of the car that end up near the rear boxes on the valance panels, i have a sneaky feeling that the turbulent airflow pulls the smell into the cabin from back there. just not sure what would happen or if its safe to seal these up.

Mmmm that's interesting to know...I guess blocking them on a temp basis could tell if it works and also provide a resolve for all us smoke heads lol

Mmmm that's interesting to know...I guess blocking them on a temp basis could tell if it works and also provide a resolve for all us smoke heads lol

 

Might try it and let you know, i also know that the valance panels do tend to suffer rust as they are in direct line from the crap the rear wheels kick up, they would not show in a MOT as its classed as acceptable in that area for some reason. (think its due to not being structural)

Ok now I'm really really peeved. Took all plastic surround from boot and found the two air vents, taped them over and went for a drive but still fumes...went home and where the vents are I stuck my hand down the holes behind wheel arches and rust rust and more rust and holes. I think I'll just give up!!! Gonna have to take back bumper off and get that welded..I wish I knew a welder....oh heck

A bit off topic I know Swampy but my last name is Marsh and amongst other names I get called Swampy is one of them!!!!!!!

Lol two marshes that own z. Bet you have better luck than I am...I'm ready to take a hammer to mine

Lol two marshes that own z. Bet you have better luck than I am...I'm ready to take a hammer to mine

 

Does sound very much like yours is getting you bogged down :whistling:

 

There, said it before someone else thinks they're funny :2guns:

Lol yep

Ok now I'm really really peeved. Took all plastic surround from boot and found the two air vents, taped them over and went for a drive but still fumes...went home and where the vents are I stuck my hand down the holes behind wheel arches and rust rust and more rust and holes. I think I'll just give up!!! Gonna have to take back bumper off and get that welded..I wish I knew a welder....oh heck

 

rear bumper isn't that bad a job, you just need to remove all the plastic liner in the boot and undo all the bolts around the inside edge and the ones on the side. can be a PITA to refit if your on your own but still doable. they wont need much welding as its just a dangly bit that isn't key to the structure of the car. just make sure you treat it properly after its welded and give it a lick of hammerite to keep the weather out as all of it is hidden by the bumper anyway.

That makes me feel so much better knowing that, thx VS...:-)

just a thought have the aiv's been removed, just thinking maybe the pipes to the exhaust are still open the atmosphere.

just a thought have the aiv's been removed, just thinking maybe the pipes to the exhaust are still open the atmosphere.

 

That would definitely do it!

Exhaust fumes in the cabin that become worse when opening the window whilst driving is often due to leaking boot rubber seal.

 

An easy way to check this is to trap a piece of paper in the boot rubber and see if it can be pulled out, try in several places to check the bottom and side edges.

 

If it is easy to pull out anwhere along the lower section then try pulling the tailgate down with the lock adjustment.

 

Jeff TT

top tip jeff, I noticed this after my respray. the rubber never went back into its original position. ever since ive had fumes :(

What's aiv dragonback??... Sorry very green to it all but learning quick