GTR almost stalls when BOOST...

[wrxhoon]

mickGTR ,i was generalising when i said about the odos .

if u know the car from new all its history then u know how many ks its done but as a rule the imports are turned back take it from me i know they are and u cant check the history cause noone will give u logs . i have an r33 and i got the jap logs cause i bought it from the original owner , he owned it in japan then brought it to aus with the original owners book and logs .

as to u r problem it could be anything but loosing boost shouldn't make it drop to 1000 rpm .

having low compression wouldn't do that either its electrical more than likely .by the way what was u r compression?

it should be 1.18 mpa (165psi ) at 300rpm

[mickGTR]

I will have to check the com report. I think it's sokmething electrical but it's hard to find because it doesn't do it all the time. Today at the lights I was just idling and then the lights went green i tried to go but the car would not budge! After i turned it on and ofand reved it up a bit it was fine again. Im thinking maybe some sort of fuel prob?

[wrxhoon]

no it doesn't sound like fuel to me if it was fuel u wouldn't be able to go hard like under load at high rpm unles the pump plays up u can check that easy though . when it stalls on u check fuel pressure then before u turn the ignition back on if u have plenty pressure its not the pump.

[MegaGTS4]

mickGTR,

I bet its one of the AFM's plug, Same thing happened to my car and it turned out to be a bad connection/wiring on the plug, after I changed the (mine was the top AFM plug) plug and some wiring all was fine. had me baffled too because it wouldn't happen all the time and after stalling and after restarting the engine it would run fine most of the time like nothing happened (this is because cranking the engine would shake the plug enough to get a good connection back)

I found mine by gently wriggling the AFM plugs/wiring and seeing if this affects idle.

I'am only trying to help!

MEGA

[mickGTR]

Thanks for that. Im having that checked. I also started thinking that it could possibly be some sort of bad fuel connection. Maybe i'll get a fuel pressure test done?

Mick

[mickGTR]

Can you check fuel pressure in the car? If so how.???

[mickGTR]

Hi again.

I did what you said and played with the leads/wiring while the car was running, and it seemed to do it all the time. I checked the conections best I could but it seemed o.k. The car is playing up more now since i have played with it, so I guess that's what it is. It was the bottom AFM I surpose I will have to replace it now, or can it be fixed. Any suggestions???

[MegaGTS4]

MickGTR,

If the plug and wiring seems to be fine, but the problem must be in that area since playing with the wiring made the problem worse (sorry about that) then it must be the Soldered joints inside the AFM have broken and arn't making full contact. After removing the AFM they can be disassembled and resoldered. The square section on the top of the AFM has a rubber seal around it that is glued in place, you will need to run a short sharp blade around the edge then carefully pry the top off the square section, there isn't anything that you can really damage there with the blade but be carefull when prying the lid that you don't break the plastic that surrounds the lid. Once inside you will see a metal box with a brass/copper lid, this box has four terminals on the plug side that can now be resoldered now that the lid has been removed. Seal the lid with some silicon sealant and refit AFM.

I hope this fixes your problem!

MEGA

[mickGTR]

All fixed now. It was the bottom AFM.

[Mick Trainer]

Certain;y is a strange one. I think that u are going to have your work cut out for you on this one. It sounds to me that for some reason the computer is shuting it all down (as when you restart it takes off.

If it was fuel it would die under hard throttle (usually) and for it to come so intermintantly soulds like somthing changes and the computer sensors it. Have youput it on a Dyno to see what air/fuel mix it is running? May be worth a look, at least it will clarify that for you. It does not sound like a simple loose conection as why does it alter when the car is turned off? I doubt the conectipn just fixes itself. I'd say that the comp is backing everything else off.

Mick.

[mickGTR]

Prob was fixed about two weeks ago! I replaced the bottom AFM works beautifuly now

Cheers