Hi again everyone,

 

Does anyone know what I can check to find out why my Zed is cutting out under acceleration? And by cutting out I mean it feels like I'm stamping on the brake...

 

I recently put a splash guard back in as I thought water was getting onto the MAF (a previous owner had removed it for some reason) and things have been considerably better. However, after leaving the car for a few days while I went away, it's playing up again today.

 

It's damp, but certainly not wet today, so I don't think it's water on the MAF. Can it be a damp/furry connector somewhere? If so, where should I be looking? Could it be a boost leak? If so, how the hell do I check?

 

As usual, any help would be very gratefully received!

Is this constantly?

 

As they cut out if you give it too much when its cold??

The car that is, not the weather

Actually no - if I only drive it in the nice sunny weather it tends to behave! That's why I was wondering if it could be damp getting into a connector or something. Not much good as this is my everyday car tho... I know that they won't boost fully until they're up to temp, but this was still happening after a 20 mile drive to work (at the Nissan Technical Center, ironically). Surely it shouldn't happen after it's warmed up?

Love the avatar by the way... hehehe

It's definately the induction which I presume you have. I had the same problem on mine. everytime it got a bit wet I got to about 3 - 4 k rpm and it just seemed to die without stalling. Replace the apexi filtre and the MAF and was good as gold.

 

Can you tell us a little more about the set up ?.

 

Single/dual pop induction, what filter you using etc.

Splash guard in place for the induction and then another under the engine ?

What vents / inlets do you have on the car that may allow moisture into the air flow.

It's definately the induction which I presume you have. I had the same problem on mine. everytime it got a bit wet I got to about 3 - 4 k rpm and it just seemed to die without stalling. Replace the apexi filtre and the MAF and was good as gold.

 

Can you tell us a little more about the set up ?.

 

Single/dual pop induction, what filter you using etc.

Splash guard in place for the induction and then another under the engine ?

What vents / inlets do you have on the car that may allow moisture into the air flow.

 

That sounds about right...

 

ive read a previous post where someone was having the same problem, problem was solved when the induction was relocated with the plastic guard underneath the filter acting as a reflector.

Yep - I do have an induction kit and yep it's an apexi cone! I did have a MAF die on me (probably from getting wet) so that has been replaced (albeit with a second hand one). And it's exactly what you describe, although today it decided to cut out at 5K rpm - sometimes it's 4K, sometimes 4.5K...

 

So set up is: single apexi cone filter, recently added splash guard (bolted on at front, sitting firmly on dump valve pipes at back due to mount being missing) and I can't see the floor, so I presume that's the under engine splash guard that you mean. I have stuck a couple of bits of duct tape on the bottom of the filter (heard that can help with my cutting out at junctions problem - it didn't) and no non-standard vents.

 

What do you reckon?

maf could be faulty then..... maybe give it a clean with intake cleaner but be gentle.. and take off the wire connector maybe its dirty with loads of green muck on it.

I would suggest taking off the induction completely and blowing it through with an air gun or a hair dryer. Make sure it's nice and clean. Then let it dry out for some time before replacing it. i.e. leave it next to a rad for 24 hours (not on the rad jsut next to it).

 

Also take the MAF out and as suggested above give the connectors a good clean and check the MAF sensor (inside the pipe), give that a blow manually (don't use a hair dryer or blow jet on this as it's quite sensitive.)

 

You should have two splash guards. One that sites under the engine (this is split into 4 sections IIRC, front engine middle back engine and two sides. You should then have another smaller guard that sits between your oil cooler and your induction, this is usually bolted on to the holes under the headlight pannel.

 

Have you got a modified nose pannel, if so it may be worth you getting some slam pannels installed to minimise the chance of moisture getting down there.

 

Most problems with the MAF / Induction getting damp / wet come from the front bumper, so it's worth having a look at this, you need the air going into the RAD's but try and keep it away from the induction.

I think it may be the problem I highlighted a little while ago of water getting between the seal of the centre panel and bumper, it then leaks directly onto the apexi filter. Sometimes the maf cannot be rejuvented so it could be best policy to replace?

Cheers guys!

 

SMW1 - I'll try that. To give you a bit more info, when I had the problem with the MAF dying the first time, I replaced it with the second hand one as previously mentioned and then stuck silicon sealant around the connector and taped it up - there shouldn't be any moisture in there! I'll have a look at the general condition of everything though and see if I can see anything. The weird thing is that it just happens in the cold and damp (and even then not all the while)... if the MAF was faulty, surely it would always happen?

 

And nope - no modified body kit at all.

 

Now - when you guys talk about the MAF/filter getting wet, do you mean properly wet, or will just a very small amount do it? The reason I ask is that whenever I have checked, the cone, MAF, pipes etc. always seem to be dry, apart from the odd drop.

 

Does anyone have any photos of what splash guards I should have?

 

And finally - should these cones be oiled? I was going to get some oil recently and good ole Halfords said that this type of filter shouldn't be...

I replaced it with the second hand one as previously mentioned and then stuck silicon sealant around the connector and taped it up - there shouldn't be any moisture in there! I'll have a look at the general condition of everything though and see if I can see anything. The weird thing is that it just happens in the cold and damp (and even then not all the while)... if the MAF was faulty, surely it would always happen?

When I said the sensor maybe getting damp, I meant the sensor inside the MAF (i.e. where the air passes through the tube, not the connector).

 

Now - when you guys talk about the MAF/filter getting wet, do you mean properly wet, or will just a very small amount do it? The reason I ask is that whenever I have checked, the cone, MAF, pipes etc. always seem to be dry, apart from the odd drop.

Getting wet will kill the MAF, what we are refering to is moisture, whether it's in the air passed through the cone or some sort of condensation, any moisture on the sensor it self will cause the MAF to send incorrect readings to the ECU, which is what you appear to be getting as it's cutting out when the MAF kicks in. However as already mentioned it could be the connections anywhere between the MAF and the ECU rather than just the MAF sensor itself. But the most common cause is the sensor.

 

Does anyone have any photos of what splash guards I should have?

I don;t have any here at work but I'll have a browse around and find some unless someone beats me to it.

 

And finally - should these cones be oiled? I was going to get some oil recently and good ole Halfords said that this type of filter shouldn't be...

Nope the Apexi should next be moistened in any way it's a totally dry filter. Oiling the filter will allow grit / dust to fuse together causing blocking of the filter which means less air getting in. I know it's been suggested on here before but I also don't like the idea of Duct tape on the bottom of the cone, it may prevent a lot of moisture getting into the MAF, but will limit air flow all the same. It's best to find the source of the moisture and fix it before you get to the induction.

not the best of pics but you can see the corigated splash guard for the induction itself in this picture.

 

Yep - that's pretty much what it looks like under my nose panel (now I've installed the corrugated part). Interesting to note that the edge closest to the engine doesn't seem to be bolted to anything on this one either.

 

As for the tape on the cone, I know what you mean - seemed a bit counter-productive to me too, but I heard that as the sensor sits in the center of the pipe and these cones can cause a vortex effect, the air could swirl around the outside of the sensor and cause incorrect readings. Apparently the tape can introduce turbulence and help get a better reading...?

 

Does anyone know what other connectors (apart from the main MAF one) I could check to make sure they're OK?

 

SMW1 - you mentioned that you replaced the apexi filter. Did you change it for something totally different or do you mean you replaced the filter material?

Does anyone know what other connectors (apart from the main MAF one) I could check to make sure they're OK?

 

SMW1 - you mentioned that you replaced the apexi filter. Did you change it for something totally different or do you mean you replaced the filter material?

 

Try the temp sensor and TPS as well if you want to check them, but I'm sure your problem is related to the MAF.

 

No Apexi as far as I'm concerned is the best for the 300zx, I replaced it with another Apexi :)

apexi is also on my wish list, i've got a k&n aston DB9 cone filter on at the moment and it seems to be ok but it will be getting changed

Heres confidence for yer!... I think I know what your problem is mate! Replace the fuel filter, mine did exactly the same until I swapped mine for a larger capacity filter. Theres a 'how to' somewhere Im sure someone will link you up to it soon! Once removed, I shook all the fuel from the old filter and you wouldnt believe the crap that was in there.

In my instance, I would accelerate hard from standing and then it was as if I had hit a limiter and the power just went! I raised off the throttle then slowly squuzed back on and it was fine.

Hope this helps you.

Oh btw I can let you have details of where to get the longer/higher capacity filter if you like.

Hmm - interesting GaiJin. As mentioned previously, I'm still getting that stalling at junctions problem, and I've read that it can be related to the fuel filter/fuel damper.

 

Another strange thing is that when I take the fuel cap off, I get no hiss of released pressure - maybe someone can tell me if this is normal?

 

It would be good if you could let me know the details for the replacement filter - even it doesn't fix the problem, it would be a good upgrade part!

 

SMW1 - Thanks for all of your help with this - I'll definitely do as suggested and see if I can sort out some extra damp proofing! Also, I have brackets holding my cone in a particular place under the panel - after seeing that photo of yours without brackets, I might try removing them and rotating the cone up and out of the line of fire a bit to see if that helps.

Another strange thing is that when I take the fuel cap off, I get no hiss of released pressure - maybe someone can tell me if this is normal?

 

SMW1 - Thanks for all of your help with this - I'll definitely do as suggested and see if I can sort out some extra damp proofing! Also, I have brackets holding my cone in a particular place under the panel - after seeing that photo of yours without brackets, I might try removing them and rotating the cone up and out of the line of fire a bit to see if that helps.

 

 

When you turn the ignition on can you hear the fuel pump fire up briefly ?

Also when you have a fair bit of petrol in the car and you take it for a spin, then open your fuel cap do you get a pressure release noise ?.

 

That wasn't mine btw, that was something I found while searching for a picture of a splash guard. This is my one. I'll be replacing / cleaning the left filter soon.

 

Oh btw I can let you have details of where to get the longer/higher capacity filter if you like.

 

Is it the only available from the fuel filter secret society :D

VERY snazzy SMW1!

 

Yeah, I think I remember hearing the fuel pump kick in before I start the engine, but I'll double check. But no - no matter how much fuel I have in the car I've never yet heard it hiss at all.

 

LOL TopLess...

VERY snazzy SMW1!

 

Yeah, I think I remember hearing the fuel pump kick in before I start the engine, but I'll double check. But no - no matter how much fuel I have in the car I've never yet heard it hiss at all.

 

LOL TopLess...

 

In that case you may have a fuel related problem as well.

 

Fuel pressure regulator or fuel pump maybe.

OK - in that case, does anyone have a fuel regulator for sale? (I'll start with the easy one first!)

 

In fact, does anyone know who the best person to speak to would be about replacing my regulator, filter and fuel line? I've been having fuel smell problems (sorted now though) so replacing the line with some braided hose might be a good idea...

OK - in that case, does anyone have a fuel regulator for sale? (I'll start with the easy one first!)

 

In fact, does anyone know who the best person to speak to would be about replacing my regulator, filter and fuel line? I've been having fuel smell problems (sorted now though) so replacing the line with some braided hose might be a good idea...

 

I think its jaffa who is selling an adjustable fuel regulator.. wore a look :D

 

yep here it is:

http://www.300zx.co.uk/forums/showthread.php?t=106019&highlight=nismo+fuel

Braided hose does not cure fuel problems, it is just engine bay bling! I think you need to do basic checks before you go buying parts randomly to cure this problem?