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Symptoms Of Faulty Afm And Injectors

ruffryder
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ruffryder Contributor

ruffryder

Posted
Posted

just wondering guys, what can u expect to see from faulty fuel injectors in the car?? and what about faulty afm??

my cars jerking n missfiring like no tomorrow, i cant even drive it to 70-80km/h

got brand new 040, spark plugs, split fire coil packs

any help appreciated

thanks

randominsanity73 Enthusiast

randominsanity73

Posted
Posted
so a faulty afm can cause all of this? jerking and popping? has anyone else had this issue? i just wanna make sure coz ive spent soo much n gotten nowhere

First off have you tried cleaning the afm? My r32 gtr was having some issues (to start with I thought it was the spark plugs too, went out and bought all new ones and had them gapped correctly haha. Problem not solved), so I removed the pod filters, took off the afms and sprayed the wires (2 little wires running parallel with eachother) with an electrical cleaner spray. There was lots of dirt build up on mine. Once that's done, flush it (NOT with water, I can't remember if i used methylated spirits or another one. I always forget what the chemicals are called until I go to use them haha. Has a very low flash point anyway). Let it dry, re-fit and see how it goes.

My car improved drastically after cleaning the afm's.

ruffryder Contributor

ruffryder

Posted
  • Author
Posted (edited)

tried cleaning it and does no good :)

u think i can directly swap it with a z32 afm if i dun have an rb20 one available? i know u usually have to tune it n change ecu, etc.. to make it run properly, but can i just chuck a z32 one in there just to see if all the jerking n popping goes away? just so i can confidently determine whether it is the afm?

if yes: are the plugs the same? n all i do is directly plug in the z32 afm?

thanks in advance

Edited by ruffryder
ish Proficient

ish

Posted
Posted (edited)

didnt want to start a new thread so i thought i would ask here. as its simular.... my R32 gtr runs really well to the say last bit of topend then just starts to spluter as its adjusts it self ....its odd because the car is potent right up to where it plato's out then goes hard again. i am guessing fuel pressure maybe?

I'm not sure that i can get this car on a dyno in this town as there all 2 wheelers and i dont really want o send all drive to the back until i undestand it more ...

Any hints before i go hunting !

Edited by ishh
Deceeve Rising Star

Deceeve

Posted
Posted

Sounds like a screwed spark plugs or fuel system to me, You might have a good look at that first before doing anything else could save you alot of money.

AFM problem normals tends to play only after hard revvin and coming to the traffic light your rev will drop and wanting to stall.

ish Proficient

ish

Posted
Posted

interesting!!! ... it sits at idle fine and nothing changes after a harder drive ...

i am thinking a plug would give a more constant miss and not just fail up top .

I am from Vl land and the learning curve is faily simular but totaly different........ i will work it out :)

ruffryder Contributor

ruffryder

Posted
  • Author
Posted

i find that the problem gets worst after a drive. like a drive first thing in the morning, the problem is still there but only at high rpm. i would park my car for like an hour, then when i start it up again, i couldnt barely drive it home. it would jerk n pop like crazy, i cant even revv past 2500rpm

DLuded Mentor

DLuded

Posted
Posted

why dont u just ask someone near you with an r32 to swap over the your AFM and drive it for 15 minutes?

i had the same problem and changed everything (plugs, fuel filter, fuel pump etc) and after changng the AFM it was perfect

with a screwed AFM i could barely drive. the car would jerk back and forth rather voilently and everyone would look at me like i was a retard trying to drive. other times the car would run smoothly with no troubles

Sacony Contributor

Sacony

Posted
Posted

i had the same problem, basically after driving around for a while it would basically shut down and only allow me to rev to 2500rpm and stall when coming to a stop.

The problem was afm's and since replacing them have had no problems at all.

But i also had other problems associated with my top end power, my throttle position sensor and neutral switch were stuffed and my fuel pressure regulator was buggered only giving 3.5 bar instead of 5. So after all those things were fixed my GTR is running very sweet.

meep Enthusiast

meep

Posted
Posted (edited)
I have same problem but from about 4500-5000rpm. Also sometimes nearly stalls at lights. Could this be afm?

does it feel like a harsh fuel cut.. mine does it too, but it sorta like splutters, then goes crazy with power... it also stalls at lights to on occasion.. and it seems to happen when the car is warm....

Edited by meep
Lazy-Bastard Grand Master

Lazy-Bastard

Posted
Posted

I had a similar (jerky) type problem with the AFM on my R33.

After much stuffing around I pulled it apart and found that 2 of the connections inside the AFM had broken.

I soldered all four of them again just for good measure, put it all back together and sealed it with silicone and haven't had a problem since.

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