I took a video of what my car is doing.

View My Video

Its hard to tell but its like a violent choking at about 3500 revs when boost starts to spool.

It done this about a month ago and a fellow member suggested a boost pipe had come off, i couldn't find anything out of place and it was fine after that day.

I put it down to air in the fuel lines as it had been sitting jacked up on one side for a while.

 

But then i could freely rev it, now it struggles.

 

My friend suggested that I've got a perished actuator pipe as this happened to his skyline, but i cant even see them let alone get to them.

 

It feels electrical to me, as if its cutting ignition.

Any ideas guys, any help is much appreciated as i'm new to these engines.

Thanks

Mark

would the fuel quality have anything to do with it as i'm using Sainsburys super 97 at the moment while my Tesco is being refurbed (they have 99)

the video link is not working properly on only about 5 seconds.on your car check all your electrical connections.also there is alot of pipe work on these zeds its worth checking all your pipes especially the intercooler pipes.lee

Its working when i click on it, might be the browser or something.

Ok ill go have a look at what i can, i do know that the injector plugs are all green, but thats just a signal of on or off surely

spend an hour or so cleaning them up as that can make a difference to the running.use a nail file/small file to clean them.it could be the problem.lee

Cheers lee

Maf fault maybe?

Ok ive just cleaned up the injector conections, even crimped them for a tighter fit (that last one at the back took too long to get back on), took it for a spin, it revved and boosted to 4500 this time,

 

I googled this and i came accross a mazda cx-7 forum, they have similar issues and its more often than not the egr valve getting all clogged and blocked.

Is this possible?

Maf faults were high on their list aswell,

sounds like a MAF to me

So whats likely to have gone wrong with the maf then, too hot, literally broken, i hear about them getting wet?

Your close to me, can you limp it over to me in wellingborough? if so we can put my MAF on it and see if that illuminates it.

can you disconnect the maf and have it running, i know this worked as a good diagnostic when my old daily hack did it. connect maf and you could drive to 2500rpm then bang like sum 1 had hit the brakes. disconnect it revved quite happily.

That will be the MAF needing replacement, see if someone has one you can borrow. Disconecting it will just give you the same fault. You can do an ecu check or put it on Conzolt to check it out too.

 

Allan

I have a spare one you can try as I changed to a Q45 one.

Vodkashots thats a very generous offer, but i doubt i could get it that far, would mean taking it on the motorway and holding up the traffic at low revvs.

However i am a student in leicester so i may be bringing the car up at some point.

If you guys are sure its the maf then ill see if i can have a fiddle with it for now, otherwise my mate will be in possession of a s15, hopefully that will have one that he'll let me test on mine.

How much are they generally, do they go often?

It may even be a coilpack on the way out

See in the for sale section I think Jimmytt has two for sale

By the way sign up as a full member its the best 20quid you will spend on your Z

 

http://www.300zx.co.uk/forums/showthread.php?t=136285

Edited September 23, 201015 yr by gruntpa64

Boost leak

Ive taken the maf off, and started the car, it wont rev freely past 3000 now.

It says to me that the maf would be getting a wrong signal from somewhere, unless it only comes into play when there is a hint of spool.

I wont be able to tinker with it for a while from tomorrow, so its gonna sit not working :(

Sparky is there no way you can limp it over to me? are you in bedford at the moment?

No, Bedfordshire, near Whipsnade zoo. About 45mins from Bedford. Im going back to uni today but i might be able to bring it up next weekend. Cheera vodkashots

I really dont think the maf is the problem though. Coil pack i can only see not working if it fires at the wrong point, making me think its another sensor.

Boost leak i rekon for it to be this severe would give a shit idle and id be able to hear it

The Maf measures the amount of air passing through it so when you open the throttle it incresses the air flow if the MAF is not giving the reading to the ecu the ecu will shut down the engine at 2500rpm, the latent increece of rpm will take it up to 2800rpm, which is where you are cutting out. You need to do an ECU test, this will tel you if anything is giving a fault code.

 

Please do a search it will help you

 

 

 

http://www.ttzd.com/tech/diagnostictech.html

Edited September 24, 201015 yr by gruntpa64

No, Bedfordshire, near Whipsnade zoo. About 45mins from Bedford. Im going back to uni today but i might be able to bring it up next weekend. Cheera vodkashots

I really dont think the maf is the problem though. Coil pack i can only see not working if it fires at the wrong point, making me think its another sensor.

Boost leak i rekon for it to be this severe would give a shit idle and id be able to hear it

 

well if you can we can try my MAF in yours, also do a search for boost leaks and just generally eliminate what it could be. also do a ECU code check as well. and as mine isn't going anywhere fast, can try coil packs as well

That page says the engine check light would come on if the maf had a problem. I dont know where the engine light is, i didnt even know it had one, but my emmissions system light come on on ignition, but i thought thats because my cat heat sensor is not plugged in anywhere.

Cheers bud.

I was going to take out all the air injection system to eliminate it from problems like these :D

Ok, i checked the ecu. Sure enough i had a check light on. Went through the diagnostics test.

I got 12 (air flow meter circuit)

33 (exhaust gas sensor circuit (left))

and

53 (exhaust gas sensor circuit (right))

So, i turned the diagnostics off and tried it again. This time i got 55 (NO malfunctions in the above)

So i took it for a spin and it was spot on, although the engine check light is still on.

 

Prior to this i had the maf in the airing cupboard overnight, just incase it had got wet, and i pushed the connectors in to make a tighter fit. Im starting to think that was the problem all along.

 

Does the engine light stay on for a few starts after the check?

I cant figure out the exhaust gas sensor codes disappearing though. Its got an aftermarket exhaust so i think they're not in the exhaust anymore.

Exhaust sensor are cat heat sensors IIRC if you have a dect these will not be connected , just dangling some where around the mid section of the exhaust area. As these are in the open air they will give a fault code and a warning light

 

Ok I have just looked at the fault code on 33 and 53 this is a fault with your o2 sensor lhs and rhs, this is now becomming a more common problem as most have never been changed, these will still be conected in your car as they deturmin the air/ fuel ratio through the ecu. If your o2 sensors are faulty the ecu will work out an average setting to alow the car to still function, although it will be on the rich side to stop det.

You need someone with a conzolt to realtime diagnose the O2 sensor fault.

The O2 sensors are in the down pipes from the turbos

 

Hope this helps

 

Allan

Edited September 24, 201015 yr by gruntpa64