I took my car to a garage in Bristol today and he diagnosed my car today as having a problem with my car running way too lean. He reckons that after doing an emissions test / lambda senser O2 Sensers etc etc that my car is not getting enough air - fuel ratio mixture. He then went on to tell me that I need to buy an AIR FLOW METER COMPENSATER MADE BY APEXI (Approx £70-£80), allegedlly they are a small box that connects up to the ecu/aft and you can manually adjust the air flow to calibrate to the fuel mixture. CAN ANYONE VARIFY THIS OR STEER ME IN THE RIGHT DIRECTION ? AS HE RECKONS THAT MY CAR IS RUNNING THAT LEAN HE IS SUPRISED THE CAR IS RUNNING AT ALL. Duffer, John Dixon, Mac, Srae, Baggins come on guys help me this on going saga of my car running right is really doing my head in and which ever way I turn I seem to come to arrive at a dead end. :cry: :cry: :cry:

Oh and by the way he went to check the PTU and low and behold it has dissapeared into thin air. UK car 1991 not original engine someone before I owned my car has re-located it and I'm buggered if I can find it would it be nearer the ECU ???

What have you had done to the engine?

Turbo's? Injectors? Chipped ECU?

 

PTU wiring comes from the right of the engine bay so it's common to relocate it above the fusebox area or further back on that side.

 

Don't ask Macca, he doesn't know anything about Z's :D

 

Don't ask Macca, he doesn't know anything about Z's :D

 

Cheeky **** you did not know how to take the bloody steering wheel off :rofl:

 

 

tat man,I would say that the guy at the garrage is talking complete *****cks,I don't know of anyone that has had an AIR FLOW METER COMPENSATER fitted to a Z :rofl:

I saw a pic a few days ago and the PTU was near the airfilter :confused:

He is adamant that you can buy an Airflow compensater and he said if I get one he will fit it, Traders, Mechanics, Enthusiasts or Technicians CAN ANYONE VARIFY THIS I REALLY NEED TO KNOCK THIS ONE ON THE HEAD ALTOGETHER IT HAS BEEN GOING ON NOW SINCE LAST SEPTEMBER. I DON'T NEED ANYMORE I WILL HAVE A GO AT THIS I NEED SOMEONE THAT CAN DELIVER THE GOODS AS IT IS REALLY BEGINNING TO P155 ME OFF NOW. I just wanna drive my Z and have it perform how it should.

Why would it run lean if it's not getting enough air?!?!

Too much air and not enough fuel maybe.

Are you running too much boost?

It has HKS Twin Intercoolers, Denso Iridium Plugs, JWT Chip, 360 Degree Hybrid Turbos, Induction Kit, De-Catted Full stainless exhaust system.

Problem is that everytime I take it somewhere to be looked at It is behaving itself, 10 miles down the and road it's up to it's old tricks again (Sods Law EH !!!)

So how much boost are you running?

What exactly is it doing wrong?

When they say it's running lean do they mean it's detonating?

If so you need more fuel not air.

I'd guess that an air flow meter compensator is just another way of saying AFR, ie box that dicks about with the MAF signal.

When it was running lean at the garage, was that on idle or under load on a rolling road? If it's just on idle then i'd say the diagnostic was crap as it will run lean under those conditions.

Looking at your mods, if the turbos are bigger than stock, then you could be running lean at high revs/load just due to injectors being maxxed out.

Is the problem you're having intermittant? What are the symptoms?

OMG this must be a first! A JWT chip running lean :eek: lol

 

IF the car is chipped then there's no need for an AFR. There is a problem somewhere else. Has the car been properly looked over? Checked for air leaks etc etc etc What exactly does it do when its not running right? I'd be looking towards the airflow meter if I were you....

 

CheerZ,

 

Andy

And just to add to the equation: it would appear that the standard injectors max out at roughly 15psi of boost. I have seen this on several cars whilst doing a run with a ConZult attached. I think it was Ryan (Baggins) who most recently encountered this problem (although I could be wrong). So if you're running more than that on standard injectors you should really be tuning boost down until you get bigger injectors. However, this would not explain why you're running that lean under stationary conditions or low loads.

 

HTH and isn't complete b*ll*x! ;)

OK, my car plays up and starts to stammer and stutter from pulling off until about 3000rpm and when the tubbies kick in it seems to be ok it just flies. But if I change from say 2nd to 3rd and then slow down so the revs are at around the 2000rpm and accelerate the same happens. It does this running on standard boost and on full boost that doesn't seem to make any difference, (I am still running on bleed valves, but at present am keeping them fully closed) I will in the next month or so get a boost controller installed but I did not want to do any more mods until I have a good solid foundation of reliability to work from. I still cannot tell wether it is an electrical or air/fuelling problem.

No it hasn't been looked over properly for Air leaks etc I have now taken it to Jeff and Central garage bristol who both specialise in Zeds, although BAGGINS has promised me he will run Conzult on her at the Bristol meeting this Sunday and give her the once over

I do want to step up to Nismo 555's in the next month, Lightened Flywheel, Lightened Underdrive Pulley etc and a Grounding kit but as I mentioned before I wanna get it running properly as is before stepping up power any further, that way I can keep tabs on any new problems that may occur in the future.

The car is driveable I have just driven up to Doncaster this weekend in her 300 mile round trip and the only times she played up was when it was really chucking it down with rain or when the the engine wasn't quite warmed up. So if any of you guys are prepared to sort this prob out for me then I am open to offers, Duffer I know I have already spoke to you about this so if an offer stands I will be most appreciative. I reckon John Dixon is closest to me in Kidderminster or Baggins ????

The car is driveable I have just driven up to Doncaster this weekend in her 300 mile round trip and the only times she played up was when it was really chucking it down with rain or when the the engine wasn't quite warmed up.

 

HMMMMM!

 

This is sounding more and more like a fooked AFM to me.

HMMMMM!

 

This is sounding more and more like a fooked AFM to me.

 

Do you reckon, it will be good if it is because I am sure that I have already Earached most of you over the last few months about wiring loom probs, coil packs, cleaning of coil pack connecters, injecter connecters etc. There was a week when I cleaned the coil pack connecters and I went around all 6 dissconnecting them 1 at a time to see if the engine revs dropped when one was disconnected and all of them were ok apart from the front left cylinder when stood looking at the car wasn't appearing to be firing, but now it seems to be running on all 6 cylinders. Question is if it is the AFM that is faulty would the car still play up when just standing on tickover ???

Yup I'd try a known good air flow meter ;) Baggins has one I think - in fact he has most things, including VD :D:D:D:D

:D :D Baggins I hope you are ready to have your brains picked by me on Sunday mate ???

Do you reckon,

 

Yea I do.

 

My next question to you is............................

 

Do you have a splash guard under your induction?

Yup I'd try a known good air flow meter ;) Baggins has one I think - in fact he has most things, including VD :D:D:D:D

 

 

:rofl:

I'd guess that an air flow meter compensator is just another way of saying AFR, ie box that dicks about with the MAF signal.

When it was running lean at the garage, was that on idle or under load on a rolling road? If it's just on idle then i'd say the diagnostic was crap as it will run lean under those conditions.

Looking at your mods, if the turbos are bigger than stock, then you could be running lean at high revs/load just due to injectors being maxxed out.

Is the problem you're having intermittant? What are the symptoms?

 

The garage that I went to in Bristol didn't have Conzult or anything flash like thet they just did a normal exhaust emissions test at 2000rpm and he said that the figures were really low for a car that was de-catted and it would pass a catalyic test and the car was running very lean. I cannot remember the figures but he said he was suprised that the engine was still running.

Yea I do.

 

My next question to you is............................

 

Do you have a splash guard under your induction?

 

I'm not sure but I will go and have a look later on, I know where you are going with this one as I read a thread about this the other day, can't remember what they did ?? Is it best to remove it ??? or re-position it ?

I'm not sure but I will go and have a look later on, I know where you are going with this one as I read a thread about this the other day, can't remember what they did ?? Is it best to remove it ??? or re-position it ?

 

You might be getting water splashing the air meter causing it to give incorrect readings.

Make sure the splash guard is protecting the filter from rain/spray.

I got a spare AFM if you wanna try, It works fine 99.9% of the time - It was failing me once every 3 weeks or so but should prove a point. I have just got a splashguard for under my induction as I was having all sorts of probs with low rev probs too. Fitting the splashguard this weekend.