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View Full Version : SR stumbles around 3K rpm, what is causing this?



**DONOTDELETE**
01-21-2002, 11:00 PM
When I accelerate the car runs fine up till about 3000rpm, then it stumbles and it will hardly gain more speed. Im not sure what could be causing this does anyone know? I thought it might be a leak in the intercooler piping but they all look fine.


Also my car has a tendency to stall when I come to a stop, could this be related to the fuel pressure? http://www.freshalloy.com/

thanks.

NOSTALGIC_HERO
01-21-2002, 11:04 PM
stopper, are you venting atmospheric on a recircuilation valve and not a Blow-off valve?

that would cause the stumbling, tighten all your intercooler pipes too, that will solve a lot of problems, about the fuel pressure, are you running a 300ztt or walbro pump?, if so than you should be fine.

AZ_Dave
01-21-2002, 11:09 PM
does your car always do this? After i got my car back (swap performed) there was a tear in my IC piping...was hard to see. Was sluggish as ****.
Dave

**DONOTDELETE**
01-21-2002, 11:27 PM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by Escaflowne:
stopper, are you venting atmospheric on a recircuilation valve and not a Blow-off valve?

that would cause the stumbling, tighten all your intercooler pipes too, that will solve a lot of problems, about the fuel pressure, are you running a 300ztt or walbro pump?, if so than you should be fine.<HR></BLOCKQUOTE>

Escaflowne please explain the difference between venting atmospheric on a recircuilation valve and not a Blow-off valve.

I have a hi flow walbro installed. if not fuel pressure,what could be responsible for the stalling then?

Dave, actually it just started doing it not too long ago.

NY S13 SR
01-22-2002, 04:14 AM
Test the MAFS connection - unplug it and see if the car idle changes. Otherwise I would really suspect an IC piping leak or vacuum leak.

For the stalling - do you have the IACV black/yellow stripe wire connected up by the battery? That is 12v switched power for the valve. Helped my stalling problem with open-air BOV venting so much I didn't even use the PITA S-AFC anymore.

_____________________________
Jeff Holden
Heavy Throttle Performance
www.heavythrottle.com (http://www.heavythrottle.com)

[ 01-22-2002: Message edited by: NY S13 SR ]

NOSTALGIC_HERO
01-22-2002, 04:42 AM
there's a difference between valves intended for recirculation (like stock nissan BOV's) and valves meant for blow off (like HKS SQV)

Venting Atmospheric on a recirculating valve will do similar things to what you described

AZ_Dave
01-22-2002, 08:46 AM
To recirculate your BOV there is a vacuum line that runs to the TB.
I would check IC piping...inspect all rubber pieces closely. It is the easiest and cheapest thing you can attempt first!
Also...if you are losing your boost, you will hear a psssh sound..that's your boost leaking out.
Do you smell fuel in the exhaust? If it runs rich that is another sign your losing boost.

Dave

**DONOTDELETE**
01-22-2002, 09:28 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by NY S13 SR:
Test the MAFS connection - unplug it and see if the car idle changes. Otherwise I would really suspect an IC piping leak or vacuum leak.

For the stalling - do you have the IACV black/yellow stripe wire connected up by the battery? That is 12v switched power for the valve. Helped my stalling problem with open-air BOV venting so much I didn't even use the PITA S-AFC anymore.

_____________________________
Jeff Holden
Heavy Throttle Performance
www.heavythrottle.com (http://www.heavythrottle.com)

[ 01-22-2002: Message edited by: NY S13 SR ]<HR></BLOCKQUOTE>

Escaflowne-I have the stock BOV.

Dave-I'll check the line that runs from the BOV to the TB, and the pipe connections again. Not too sure about he lost in boost though.

Jeff-For the wiring by the battery I actually extended it over to where it was orignally located on the SR clip, which was by the stock intake by the fuse/relay box on the turbo side. I followed your webpage's instructions for connecting the wires. The black/yellow wire was connected from the SR to the KA. Where should I connect the brown wire that powers the O2 sensor? right now it's feeding off 12 volts by the fuse box.
Also for the CAS, I left mine the way it came, does it need to be adjusted? I wasnt sure from reading your install page.

Thanks again guys.

Chan (pronounced "ch-jon")

**DONOTDELETE**
01-22-2002, 10:23 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR> Also for the CAS, I left mine the way it came, does it need to be adjusted? I wasnt sure from reading your install page. <HR></BLOCKQUOTE>

It could be your timing. It sounds kind of like your timing is retarded. Start the engine and bring it to operating temp. Unplug the TPS sensor and set the idle to 750rpm. With the TPS still unplugged, hook up a timing light by wraping the pick-up around the grey wire on the #1 coil pack. Check timing by pointing the timing light at the crank pulley. It should be set at 15 +/-2 degrees BTDC (second to last notch on the right). If it's not set to 15degrees, turn the CAS until the desired timing is achieved. Plug the TPS back in and you should be good to go. Good Luck

Yury S Lyalko
01-22-2002, 10:23 AM
Also, theck your timing. It should be between 15-20 degrees. Seems like you might have it set at a lot less.
Check the timing directions on www.srswap.com (http://www.srswap.com) (SR FAQ)

Later
Yury www.srswap.com (http://www.srswap.com)

**DONOTDELETE**
01-23-2002, 12:40 AM
yep like everyone said it's either one of these:

1. leak in intercooler piping
2. bad mafs or mafs wiring
3. wastegate line
4. timing

my car has jerked really bad at one time or another from the first 3