stalling issue

[evolution23]

I recently just changed my fuel filter, cleaned my MAF, new dry air filter, and did an oil change on my 1990 gts-t. car seems to be running great now, but every once in a while ill be out driving, the car will be warmed up and running fine until i come to an intersection or light and the idle drops to the very first line (i believe its around 300rpm?) and if i dont tap the gas it will stall. It used to do this only once in a while but lately, especially today, its been doing it more often. My fuel filter looked clean, Splitfire coils with NGK plugs gapped to .8 (running 11 psi, had gapped to 1.1 before but runs better at .8). Also it will do this more often when im under half a tank, closer to 1/4 tank. I am assuming it might be my fuel pump or line, i can hook up a pressure guage but im not sure what kind of pressure it should be reading. I run 94 octane, it is running rich. Not sure if that has anything to do with this though.

Also on start up i get a kind of grinding sound, its loud and sounds like its coming frmo either the back of the engine by the firewall or possibly under the center of the dash. This might have something to do with it, im not sure.

So if anyone can tell me what kind of pressure i should be seeing thatd be great, if i am getting the right pressure then i guess my next check would be a flow test? Any ideas appreciated. thanks!

[Woodly]

A few people have had problems when regapping to .8 from 1.1 http://forums.gtrcanada.com/gt-r-tec...-rb26dett.html
Try setting it back to 1.1 and see it that solves it.

As for the grinding I have no idea lol.

[trickey1991]

dude ..the gridning on start up is ..literally almost all RB20DETS do that..mine does is...my buddies does it.my other buddies does it...its an RB20 thing .. Some people say its the clutch if u have an aftermarket clutch.but i dunno..my makes like a shinging noise..almost imagine ina movie a guy taking a sword really fast outta his holster makes like a tingy shingy tingy shingy noise lol

[evolution23]

Woodly - Ill get another set of plugs, ill try some new plugs at 1.1 and if that doesnt work ill try new plug at .8 and see if that solves the issue. Its usually just a quick drop in idle when i come to a complete stop with the clutch and brake fully pushed down. Idle just keeps dropping when i come to a stop and then either stalls or sometimes comes back up to around 800, othertimes i tap the gas and bring it back up.

trickey1991 - yeah i know the sound your talking about but no mines more of a grunting/growling lol. its like a grrRrrRrrRrr (kind of similar to the sound of the rear wiper motor but much louder and deeper) for 2 - 3 seconds, the clutch is about the right area that the sound comes from so maybe thats all it is. The previous owner said something about a gtr clutch in it? I wasnt sure wether it was a pump dying on me or what was going on. Ill see if i can get a video of it cause im not 100% convinced that its just an rb20 thing, it has only started doing this in the last 3 - 4 days so ill see about getting a video and hopefully that will help. Hopefully its just an rb20 thing.

[Nismo_line]

let us know when you change the plugs and if it does anything because mine does the same thing. if i have to come to a quick stop it will idle down but doesnt recover and stalls. i recently installed plugs and gapped them to .8

[beacher1B0]

Are you running an atmospheric BOV? Could cause some problems when coming off throttle.
Also have u tried lookin at your Iacv valve? Maybe a little diagnosis and cleaning to be done.

[Skym]

I had that type of problem before. Can test to see if it's the same problem by turning aircon, etc on while moving around a carpark or going up a hill and backing off throttle. If revs drop, then it's TPS related.

What I found out is it's not touching idle contact inside TPS. When TPS hits idle contact, stock ECU switches to idle tables. When it doesn't touch idle contact inside TPS, ECU doesn't switch and revs can drop, nearly stall. Sometimes TPS is stuffed and needs replacing.

Also intake airleaks are another cause if not the TPS.

[evolution23]

Checked for air leaks, pressure tested at 12psi for my turbo and found nothing. Filled up late last night, had it only almost stall once since then where as before i fueled up it was doing this almost everytime yesterday.

Changed the plugs today, gapped to .8, idles better, revs up quicker, red lines pretty easy. Drove it for a bit today, still almost stalled.

And i dont believe my BOV is venting to atmosphere, double checked any line i can find, no visible or audible cracks/splits etc..

My a.c doesnt engage and is empty but anyways i did turn on my a/c while going up hill and threw it in neutral and let off the gas (before cleaning AAC) and the idle dropped to 0rpm but when i tapped the gas because i thought it stalled it stumbled then revved back up...?

Cleaned the AAC, idles around 700rpm, when i come to a stop now the idle stops at about 1000 rpm and then after 2 - 3 seconds it drops about 100 rpm each time until it gets to 700 rpm. Havent had it almost stall yet, will update if it does tonight/tomorrow.

Lastly when i was under the hood i lost a bolt and had to take the timing belt cover off to retrieve it, in doing so i noticed that my timing belt is rather thin. Its maybe 1 inch wide, if that. Something just doesnt look right when i look at it. It isnt even half the width of the gears. Wondering if there is supposed to be either a second belt or if the timing belt is supposed to be much wider?

I will keep posted.

[Nismo_line]

did you completely disassemble the aac valve to clean it? or how did you clean it?

[Woodly]

Sorry maybe I misunderstood the first post, were they originally gapped to 1.1? Or were they .8 before? If so try 1.1, also some plugs spec .9, which is odd and while seems useless can make a difference. As stated above too, an atmospheric BOV can do what you're describing. Keep us posted.

[evolution23]

did you completely disassemble the aac valve to clean it? or how did you clean it?

Removed the 4 bolts holding it, then removed the motor (not sure what its called) anyways, then i ran engine component cleaner (degreaser) through the springs, cleaned both parts really good. then put them back together, then before bolting it back i cleaned the passage way with q-tips. Let everything dry, reassebled it. the idle hasnt dropped yet since doing this. Im not sure wether i did a good job of cleaning it or not and its to early to tell if it worked or not yet. Car seems to be running a lot better now, feels like its got more power since the new plugs, idles around 700rpm.

Sorry maybe I misunderstood the first post, were they originally gapped to 1.1? Or were they .8 before? If so try 1.1, also some plugs spec .9, which is odd and while seems useless can make a difference. As stated above too, an atmospheric BOV can do what you're describing. Keep us posted.

The old plugs were gapped to .9, they were in need of a change anyways. Bought a new set, gapped them to .8, seems to be running great. Feels like i have more power as well now. And im not sure what i was thinking earlier when i said my BOV isnt atmospheric, it definitely IS releasing to atmosphere. Greddy BOV

[Woodly]

Removed the 4 bolts holding it, then removed the motor (not sure what its called) anyways, then i ran engine component cleaner (degreaser) through the springs, cleaned both parts really good. then put them back together, then before bolting it back i cleaned the passage way with q-tips. Let everything dry, reassebled it. the idle hasnt dropped yet since doing this. Im not sure wether i did a good job of cleaning it or not and its to early to tell if it worked or not yet. Car seems to be running a lot better now, feels like its got more power since the new plugs, idles around 700rpm.



The old plugs were gapped to .9, they were in need of a change anyways. Bought a new set, gapped them to .8, seems to be running great. Feels like i have more power as well now. And im not sure what i was thinking earlier when i said my BOV isnt atmospheric, it definitely IS releasing to atmosphere. Greddy BOV

COULD be you problem right there, I'm know expert as I went with the recirc instead but many, not all, people who go with a recirc BoV with stock ecu or mild ecu tune will notice these problems as the car things it is wither not getting enough air return or runs as if it's leaking(something like that like I said no expert haha). Try reinstalling the stock, or another recirc bov and see I that helps at all. Hope this helps!

[evolution23]

COULD be you problem right there, I'm know expert as I went with the recirc instead but many, not all, people who go with a recirc BoV with stock ecu or mild ecu tune will notice these problems as the car things it is wither not getting enough air return or runs as if it's leaking(something like that like I said no expert haha). Try reinstalling the stock, or another recirc bov and see I that helps at all. Hope this helps!

I dont have a stock BOV but if i come across one or finally decide to get a new one ill look into a recirculating BOV. Anyways thought, car is running much better, took it for about 10 hours of driving today to the coast. It is still having the stalling issue so BOV is a possibility. i have a new MAF, im going to clean it up then throw it in and see how it runs. As far as this issue goes though im not really sure what else is could be other than either BOV or TPS. new plugs gave me a nicer idle and faster red line/more power, cleaning the AAC made the idle issue much less frequent (might not of cleaned it well enough maybe?) so other than that, im not sure.

[beacher1B0]

Idle at 700 rpms is pretty close to the factory spec of 650 rpms RB20 5spd.

If the stalling occurs when you take your foot off throttle and on clutch(gear changes, traffic lights, stop and go traffic) I would suspect a atmospheric BOV. Also you should be getting the occasional burb/backfire out the tailpipe in between gear changes with the Atmo BOV.
Many who run Atmo BOV just learn to deal with it by blippin throttle before it would stall. Also you could get your ECU tuned/chipped/Rom'd which would help a little. Running Atmo isnt really bad for any parts except your O2 sensors and Cat Converter. The extra fuel will shorten the life span of those.

The more maintenance you do(cleaning/adjusting to spec/replacing) will help your RB in everyway.
Also, you could clean and adjust IAC Valve. Idle Air Control Valve. Located on the rear of the Intake manifold.
If you dont have it already, you should find the R32 engine manual and download it.

[Nismo_line]

^^ this is what mine does maybe happens 1 a week or two. only goes to die when i have to come to a quick stop. i remembered that i cleaned the aac before and put new plugs in also cleaning the maf aswell. plus i have a atmospheric bov. if you are looking to solve this issue i have the factory bov i will sell for cheap