hi guys,ive just been down south from the N-E

.while driving down the M1 at a steady ton i occasionally got a little kick from the engine,now this is only happening at that speed, about 3000rpm - 3500 rpm.

ive also had my fuel mixture lowered as the car was running rich,

maybe it could just be this ,what do you think????????

jaylox

theres a saying "you can run rich a million times, but only lean once"

 

Leaning out a fuel mixture can be dangerous buisness.

Im curious to know - how did you lower your fuel mixture.

 

?? Sounds to me like you have a serious problem in your fuel maps somewhere - You car is more that likely leaning out which is waht is causing the kick. I would not run the car again untill you have rectified the problem as what Warren posted is soberingly true !

 

I take it this has only started happening since the fueling was changed ?

 

 

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Z ya

 

Nico91TT

 

 

God is coming ...and he dont have stock turbos . . .

a local garage who has done rebuilds for me said they turned down the fuel mixture as they said it was running rich.its only been happening since!

i think i'll take it back and see what they say.

thanks guys i'll get it checked

 

could boost jets be the problem?

at the time it was raining very hard,you dont think it could be this?

Originally posted by jaylox:

at the time it was raining very hard,you dont think it could be this?

If you have a HKS filter it can run like a bag of shit in wet weather,ask Tezza the problems he has had .

 

 

 

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Originally posted by MAC 1:

Originally posted by jaylox:

at the time it was raining very hard,you dont think it could be this?

If you have a HKS filter it can run like a bag of shit in wet weather,ask Tezza the problems he has had .

 

Ive never had this problem?

 

All airfilters are almost the same in desing, so if this happens to one it is likely to happen to any of them.

But i suspect whomever messed with your fuelling may have done this.

 

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YOU LAG YOU DRAG

 

[This message has been edited by 300z (edited 28-05-2002).]

I think the point with the HKS filter is that it CAN let water through under extreme conditions which in turn hits the hot wire, cools it down and gives a momentary false reading. The arguement that these filters wreck airflow meters is SHITE IMHO - if the filter is installed with splash guard then no problems should be experienced... The other arguement is that the filter oil is drawn off the filter onto the hot wire clogging it up over time... Again SHITE!! If this was the case the blitz filter would knacker the MAS every time you followed a smokey bus.....

 

 

CheerZ,

 

Andy

thanks for the advice guys,i'm gonna start with getting the fueling checked at the garage.they can sort it out ,the money ive spent there i'm sure they will find out whats wrong,hopefully it wont cost me too much!

cheers jay

For Warren and Duffmuff,Go and check out Jaylox rides before you make silly comments there is a great big dirty gap where the spoiler has been fitted,this problen has happened in very heavy rain not the dry,therefor it must be water causing the problem not mixture,that HKS filter will act like a huge sponge and suck all the water in the air flow meter,Any air intake will do the same when you have a 1" gap in the spoiler,but Terry has f**ked two air flow meters with the HKS induction.

 

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just spoke to the guy at the garage and he reminded me about how shite my my wiring loom is!

when i had my 2nd engine installed(cheaply)

 

the guys who installed the engine just ripped my loom off and back on and most of the clips are cracked or split,some spring clips are missing,same goes for the front of the engine (crankcase sensors)

so looks like im in need of a new loom

any help in finding one of these would be appreciated!

he also said due to the water damage i had after a later rebuild (got caught in a flood and the ecu got submerged)it could be problems with the ecu???

looks like i have some dosh to spend

also any more advice will be appreciated1

thanks guys jaylox

All im saying is i have driven my car with an HKS air filter in heavy heavy rain and have yet to have that problem? So i dont see how that could be the problem, as i ve never heard of that although im sure it could happen.

 

And if it happens to one filter it can happen to any of them.JAYLOX QUOTE -"a local garage who has done rebuilds for me said they turned down the fuel mixture as they said it was running rich.its only been happening since!" THAT MAKES ME THINK IT HAS TO DO WITH FUELLING?

 

 

Originally posted by 300z:

THAT MAKES ME THINK IT HAS TO DO WITH FUELLING?

 

But surely if that was the case it would happen in dry conditions???

 

 

 

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Well thats a good point lol, suppose i should have read that.

I humbly appologise. But i was basing this on his first post which does not mention rain or anything.

Still curious about how the fuelling was altered though .....

Originally posted by AndyP:

Still curious about how the fuelling was altered though .....

Me too???

 

 

 

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This is how i see it:

 

There is one of three strongish possibilities here - If i assume that this problem only happens in heavy rain .

 

1) Your filter is gettin clogged and the car is stumbling coz it can't breath wich is casuing a lurch at low RPM - i dont know the exact phenomenon as i haven't been in the car.

 

2) The Water thru the Filter is fuckin with MAS reading casuing the ECU to issue the wrong Ammount of Fule thus you are running lean now and again which causes a hitch as it were.

 

3) the moisture is effecting the MAS,CAS, TPS or any other part of a less than perfect loom again possible and will cause effect such as what you descibe coz again the mixture may not be correct.

 

4) if It does happen in the Dry as well your mechanic had fucked up your car - as other people have said there is not easy way to alter the fueling on a 300zx without friging something into the EFI or Doining something i dont even want to consider with your Fuel lines - Or doing it properly and added a adjustable FPR or a AFC which change the pressure at the Fuel Rail or trick the ECU into thinking the Air flow is something other than what it is !

 

 

What i suggest you - Fist get the Gap above your Facia filled. The try going back to your Stock Air box - OR did the garage that fitted your car nick it ?

 

I would also strongly suggest a Mechanic takes it for a spin with a Consult hooked up and checks the Readings from your O2's !!!

 

Good luck

 

 

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Z ya

 

Nico91TT

 

 

God is coming ...and he dont have stock turbos . . .

much appreciated advice,thanks very much nico.

to anyone reading this thread:-the advice we all get off people who no there zeds is well worth paying a fee to come on this forum,i hope you guys who run this site can sit back and just do this site for a good livin,you deserve it!

thanks again everyone

Jay, The ECU didn't have any signs of water damage - inside or out.

 

noticed that 2 mate

Jay, is it like a stumble, sudden split second kick or loss of power? Mine did this a while back, would be cruising along at say about 70mph and it would feel like it had missed! Then fine for ages and then would do it again for no apparent reason. Mine was fine after it did it about 5 times or so. Last few months before it went into the bodyshop it hadn't repeated it.

 

I know it doesn't help but just thought I'd mention that I had experienced something similar. Never when raining though!

 

 

 

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it happened a few times in good weather but it was very very slight ,a split second drop in power like stumble,then when i really noticed it was in a real good thunderstorm the road was really soaked ,aquaplain time,and this time there was a heavy sudden jolt and splitsecond loss of power,what i couldnt understand was every single time i was doing 100 mph and at a steady 3000 rpm.it didnt do it at any other speed or rpm....i'm baffled totally

 

after all the advice ive had i guess it sounds like something electrical,so i'm gonna start with the loom.

hopefully i wont have to worry too much unless it pisses down.

Simply because I dont recall anyone telling you to in the thread..

 

You have pulled the ECU fault codes off, haven't you? To see if it's telling you something obvious..

 

Mine did a similar thing on a totally random basis - the cause was crappy wiring to the CAS casusing the ECU to think the engine had stopped turning, this delivering no fuel, until it made a connection again and blam, fuel... CAS and MAF faults (well, total disconnections at least) will show up as stored faults AFAIK.

 

Az

i'll give that a go mate!havnt tried that yet,my car seems to be running fine now,now the rain has stopped!.

i'll give that a go anyway just to check

I have little to add to the advice you've received already but, like others, am interested to hear how the mixture has been adjusted. I know you mentioned that you had some knowledge of the history of the mechanic but you should ask HOW the mixture was altered. Post the response on here and we can give you thoughts on the effectiveness.

 

My next bit is a bit uncertain but others may be able to clarify.

 

Either Jap or UK models (I don't remember which) use closed loop fuelling below 3,000 or 3,500 rpm. This means that the fuelling is affected by the reading of the O2 sensors.

 

If you have the type that does this (and I THINK it's Jap), then the feeling you're getting may be caused when the ECU switches over from closed loop to pure fuel map.

 

Once again though, understanding what was done by the mechanic to the fuelling would help.

 

Finally, one other factor in relation to fuelling and wet weather is that air gets denser when it's cool and wet. However, I'd expect the MAS to pick this up.

 

Dave

to dave and all the guys who gave me advice,i'll find out how,what,when,why,about how the garage managed to turn down the fuel mixture on my car,sounds like this has baffled a few of you so ill ask in the next couple of days

dave my car is a uk (93) so i dont think ur advice will be true unless it applies to uk cars,thanks very much tho to all of you

jaylox