RPM'S Drop

[87ttsupra]

Ok so i noticed a strange event happening with my supra the other day. I was driving to work and the stoplight turned red so i pushed the clutch in and i watched as the rpm needle droped all the way down to 200rpms then it went back up to idel at about 1000rpm. it has done this a couple of times. im starting to think maby i have a bad coil pack or maby a bad sensor. any ideas please.

 

[grimreaper]

Have a friend push the clutch in while you look at the harmonic damper. Does it move? Even the slightest bit? Can you see any wear marks on the timng cover right behind the harmonic damper?

What pressure plate do you have?

 

[87ttsupra]

Have a friend push the clutch in while you look at the harmonic damper. Does it move? Even the slightest bit? Can you see any wear marks on the timng cover right behind the harmonic damper?

What pressure plate do you have?

i havent done anything to the trans so as far as i know its the stock. um il check the harmonic damper as soon as ican could that realy cause a problem?

 

[dumbo]

codes? mods?

 

[87ttsupra]

codes? mods?

no codes yet. um intake 3inch exhaust ic ichard pipes 2.5. turbo xs bov turbo xs mbc turbo timer running 10-12 psi

 

[D7MSupra]

Have a friend push the clutch in while you look at the harmonic damper. Does it move? Even the slightest bit? Can you see any wear marks on the timng cover right behind the harmonic damper?

What pressure plate do you have?

clutches that are rated for higher hp apps put more pressure against the flywheel when engaged than a normal clutch does. this causes the crankshaft to be pushed forward which isnt good bc everything goes out of alignment in the motor. thats could be causing the motor to loose it speed when the clutch is engaged at lower rpms. if so better start collecting parts for another build.

 

[djazem1]

it could be you BOV i know on my brothers mr2 and on my car if you rev it hi and put the clutch right in the car will studder somtimes even stall on me.....not saying its your problem but its simmalir to the problem i have

 

[dumbo]

no codes yet. um intake 3inch exhaust ic ichard pipes 2.5. turbo xs bov turbo xs mbc turbo timer running 10-12 psi

Is your BOV vented by any chance?? With stock AFM?

 

[sneakypete]

my bet is the BOV. either recirculate it or go speed density
-pete

 

[RazoE]

you're boosting and your venting BOV is letting metered air out, which the ECU has already added the right amount of fuel to, causing you to run rich for a few, and sometimes you'll run too rich and it'll stall out on you..

you can downshift and brake at the same time to a crawl and then push the clutch in (what I do), or you can recirculate your BOV..

 

[dumbo]

he hasn't said it IS vented yet...

 

[RazoE]

he said he has a turbo xs bov, those look like this..

 

[dumbo]

he said he has a turbo xs bov, those look like this..

ohhh gotcha yah i'd say that'd be a/the problem.

 

[noel]

i have the same act problem i also have that BOV but for some reason it hasnt done this foor a while and i have my bov vented to air
ill floor it in 1st and step on the clutch and watch my rpm go down to almost 0 and it would go right back up to 1k rpm
i had to redue my cps wires and i think it fixed it does the CPS wires have anything to do with it?

 

[Rennat]

you all realize that we have a PULL type clutch so your not pushing shit against the crank, your pulling it back....


and BTW, turbo xs makes a bov that recirculates, I HAD ONE.

 

[RazoE]

R154's are pull, W58's are push, so if he's swapped on a w58 like me, it might be a possibility..

also, the BOV has interchangable tips and it is possible to recirculate, like my HKS ssqv has a recirculating tip on it at the moment, but I cannot find 1 inch diameter hose anywhere..

 

[87ttsupra]

my bet is the BOV. either recirculate it or go speed density
-pete

ok so speed density isnt something i know:aigo: so if someone could explain what that is. thanks. and its the r154 and yes im vented to the air

 

[jetjock]

http://letmegooglethatforyou.com/?q=speed+density

 

[grimreaper]

LMAO!! priceless!

 

[Muzy]

Thats funny Jetcock. It was WTF....ooh LOL..