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View Full Version : sr sputters in 2nd and above gears around 5500-6000 rpms



thecmv
04-13-2002, 02:21 PM
the car is fine in 1st gear. in second and 3rd the car reaches boost fine but around 5500-6000 rpm it starts to sputter. the rpm just doesn't move up any more. it reaches and holds boost fine before that. it seems to be a fuel problem because its worse with the profec b on. with the profec b it does it in 1st gear.
any insights?
thanks

AZ_Dave
04-13-2002, 04:17 PM
Well what fuel pump are you using (and age)

thecmv
04-13-2002, 11:22 PM
brand new walbro 255lph

AZ_Dave
04-13-2002, 11:40 PM
Possibly a MAFs or TPS problem...with a brand new pump, it hardly seems like it would be a lack of fuel.

blacksr
04-13-2002, 11:58 PM
how much boost are you running? do you have an afc? stock mafs? it could be maxed out like mine.

Hugh
04-14-2002, 02:09 AM
air flow meter.

SRFiveTen
04-14-2002, 02:41 AM
Originally posted by thecmv:
any insights?<font size="2" face="Verdana, Arial[/img]check engine light might tell, if you have one hooked up and set your ecu to self diagnosis mode.

my c.e.l. is a bare red clearance lamp bulb with two wires soldered on to the bulb.
one end goes to 12v source, other is attached to a wire coming from c.e.l. pin, which i believe is #32 (orange? i forget, i will confirm on this when i check my car again) on s14 sr20det.

if the ecu detects problems, it can throw various codes. since you already have an english copy of s14 sr20det fsm, answers and solutions should be available.

thecmv
04-14-2002, 09:54 AM
i am running stock air flow meter. stock blowoff valve, greddy front mount, 3" dp, Dual n1. i have an apex1 s-afc. my stock booost is only .4 bar according to my blitz boost guage. it stutters in 2nd gear around 6000 rpm. Can the maf's be maxed on that much boost? where can i get a good deal on a z32 maf?

chuck: so on my late model s14 ecu if i go to pin 32 i should find an orange wire? find a bulb hook one end up to a 12 v and the other up to the ecu?

SRFiveTen
04-14-2002, 01:56 PM
Originally posted by thecmv:
i am running stock air flow meter. stock blowoff valve, greddy front mount, 3" dp, Dual n1. i have an apex1 s-afc. my stock booost is only .4 bar according to my blitz boost guage. it stutters in 2nd gear around 6000 rpm. Can the maf's be maxed on that much boost? where can i get a good deal on a z32 maf?

chuck: so on my late model s14 ecu if i go to pin 32 i should find an orange wire? find a bulb hook one end up to a 12 v and the other up to the ecu?<font size="2" face="Verdana, Arial[/img]i thought that s-afc featured mafs signal monitor with which one can varify how much of the mafs capacity is being utilized.
my power fc displays the voltage, i believe 5v is max.

as fot the c.e.l., my pre-historic ride doesn't come with factory installed check engine light.
so, a bulb had to be introduced to the dash.
your ride should have a c.e.l. in the dash cluster. if so, find it's circuit and confirm it in your u.s. fsm, hook up the signal from your sr ecu and the bulb should light up each time you turn the ignition key to "on" and each time your ecu detects problems (detectable through the system)

haven't been to my car yet,,,, i'll let you know about the wire coloring.

Hugh
04-14-2002, 02:04 PM
You can read your MAF usage in percentage on the SAFC. Of course nobody knows how to use it properly...

Look at the Air Flow percentage. It is a measure of how much of the MAF capacity you're using.

thecmv
04-14-2002, 10:39 PM
so if the air flow is at 100% then that is the problem and i need a z32?

i will try to hook up the cel this week.

blacksr
04-14-2002, 11:08 PM
that is correct. if it is anywhere in the high 90's, you need to upgrade.

SRFiveTen
04-14-2002, 11:13 PM
Originally posted by thecmv:
i will try to hook up the cel this week.<font size="2" face="Verdana, Arial[/img]pin 32 is on bottom row (seen with the notch on top), second pin to the right of center bolt. color should be orange. (s14 sr20det)


Originally posted by thecmv:
so if the air flow is at 100% then that is the problem and i need a z32?<font size="2" face="Verdana, Arial[/img]stock s14 mafs is supposed to flow enough air for 280~300hp@crank motor.

some claim that z32 mafs can be dialed in with s-afc.
only example i have seen was s13 sr20det mafs on s14 sr20det with s-afc, this was not a success story. i ended up selling my spare s14 sr20det mafs to the unfortunate owner, who then ran the motor without the s-afc.

[ 04-15-2002, 12:20 AM: Message edited by: SRFiveTen ]

Hugh
04-15-2002, 02:06 AM
I am using the Z32 air flow meter through an SAFC. It is very easy.

I'd have to say if you are over 85%, its too much. The stock S14 air flow meter is definitely not good for as much as its rumored, the Z32 meters more than double. (not to mention passes more air due to size)

thecmv
04-15-2002, 09:20 AM
ran the afc today, and afl was about 60% when the engine started cutting off. it makes a back fire noise around 5800 rpms. so i ried to disconnect the s-afc and same thing. i will attempt to hook up the c.e.l now.

thecmv
04-15-2002, 10:07 AM
i wired up the cel
the light just stays on when the key is in the on position

04-15-2002, 10:12 AM
Originally posted by thecmv:
i wired up the cel
the light just stays on when the key is in the on position<font size="2" face="Verdana, Arial[/img]Does the light stay on when after the engine is started? If so, read the code from the ECU.

Asad

thecmv
04-15-2002, 10:54 AM
the light turns off after u turn the engine on. i tried to look for a light on the ecu but there is none. i was reading in the fsm on where u have to connect the CHK and IGN on the Data link consultant to switch to mode 2.

SRFiveTen
04-15-2002, 02:40 PM
Originally posted by thecmv:
chuck,
there are 3 screw on one side of my ecu and one on the other side. i dont think those screws are made to be turned. <font size="2" face="Verdana, Arial[/img]oops, my bad, late s14 ecu don't have the diagnosis screw,,,,, mine is pre-obd-ii.

you were on the right track with your data link plug, chk and ign for two seconds deal.
however, if you did it correctly, and if you have no problems, you should get a 55.

thecmv
04-15-2002, 06:49 PM
i looked all over in my 240sx fsm and there is no info on the chk and ign positions on the data link harness. i guess it would only be in the obd 2 fsm. what now chuck?

04-15-2002, 11:04 PM
Originally posted by thecmv:
the light turns off after u turn the engine on.<font size="2" face="Verdana, Arial[/img]Well, at least your CEL is functioning properly (it's supposed to turn on with the key in the "on" position and the engine off)...

Btw, check your plug gap.

Asad

thecmv
04-15-2002, 11:12 PM
so i guess my ecu isnt throwing any codes
let me go check my plugs again

SRFiveTen
04-15-2002, 11:18 PM
Originally posted by thecmv:
so i guess my ecu isnt throwing any codes
let me go check my plugs again<font size="2" face="Verdana, Arial[/img]you gotta turn the idle adjustment screw/diagnosis mode selection screw on the side of your ecu for your ecu to begin the diagnosis.

if you have no codes, the light will blink 5 slow blinks and 5 quick blinks, 55, meaning all'z gude.

Yury S Lyalko
04-15-2002, 11:24 PM
Just a guess here... We hear this a lot from our customers. The wiring behind the engine gets smashed (when putting the engine in).
Make sure the wire that went through the firewall and in the back of the head are not shorting out to the chasis.

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

SRFiveTen
04-15-2002, 11:47 PM
re-checking the late s14 sr20det wiring, your c.e.l. wire is orange, but it is pin#24, same location as on early s14 sr20det ecu coupler.

CHK on your harness, is pin#23, green/red coming out of the ecu coupler, next to your c.e.l. pin.

connect the g/r wire to a 12v for two seconds while the ignition key is "on", and you'll initiate the self dianosis mode 2.
by starting the motor from mode 2, you'll initiate the o2 sensor monitor.
key "off" will return you back to mode 1.

mode 1, checks the lamp, while the key is at "on", lamp lights up. once you start the motor, lamp turns off, as long as there is no problem.
warning lamp during mode 1:-
ecu problem,
overheating issue,
coolant temp sensor issue,
the c.e.l. will remain lit.

mode 2, self diagnosis mode.
if no problem, the c.e.l. will blink code 55.

mode 2, o2 sensor monitor.
this gets kinda difficult to explain. i think your usdm s14 fsm should explain in not so plain english.

thecmv
04-15-2002, 11:51 PM
chuck,
there are 3 screw on one side of my ecu and one on the other side. i dont think those screws are made to be turned.

yury,
i taped up all the wires on the back of the head by the firewall when we first got the motor started, because one of the wires for the coil packs were rubbing against the valve cover.

Yury S Lyalko
04-15-2002, 11:53 PM
OK, but make sure that htat wire is not shorted withing the harness. it might short itself on a wire next to it.

Yury

thecmv
04-20-2002, 12:30 AM
i finally got a chance to hook up the CEL
to my surprise and delight, it flashed 55.

so i checked the gap on the plugs once a gain to my surprise and delight it was gapped betwwen .035 and .040 so i regapped it to .028.
i thougth for sure this was the problem, so i took it for a spin same thing. dies around 5800.
it the boost controller on and set to .6 bar it dies around 4000. it seems like the more power u give it the sooner it dies. Running out of options i went ahead and changed the fuel filter too. but that wasnt the problem either.

i donnot where to go from here. the only thing not working that i can think of is the speedo doent work, and the bnoost sensor isnt hooked up.

any more insights?

thanks

Hugh
04-20-2002, 02:45 AM
AIR FLOW METER (I say again)

This is a classic problem. It always does the same thing. You flow more air (higher boost) you run out of fuel sooner. Turn your boost way down and it will wind out to much higher RPM's.

SRFiveTen
04-20-2002, 08:23 AM
Originally posted by 1bad180sx:
AIR FLOW METER (I say again)

This is a classic problem. It always does the same thing. You flow more air (higher boost) you run out of fuel sooner. Turn your boost way down and it will wind out to much higher RPM's.<font size="2" face="Verdana, Arial[/img]i don't think his mafs is maxing out, because;


Originally posted by thecmv:
ran the afc today, and afl was about 60% when the engine started cutting off. it makes a back fire noise around 5800 rpms.<font size="2" face="Verdana, Arial[/img]
Originally posted by thecmv:
it the boost controller on and set to .6 bar it dies around 4000. it seems like the more power u give it the sooner it dies. Running out of options i went ahead and changed the fuel filter too. but that wasnt the problem either.

i donnot where to go from here. the only thing not working that i can think of is the speedo doent work, and the bnoost sensor isnt hooked up.
<font size="2" face="Verdana, Arial[/img]s14 sr20 ecu expects vss sent from the transmission and processed by the speedo.
i believe ecu vss input is required for controlling vtc solenoid and also for governing the fuel cut.

here's a translation from jdm s14 reference:-


fuel cut at vehicle speed 0km/h (when there is no vss input)

fuel cut begins when engine speed exceeds 5000rpm
and high load condition is sustained for 11 seconds.
fuel cut recovery, when engine speed falls below 4500rpm.<font size="2" face="Verdana, Arial[/img]chris, vss might be your problem.
if other gauges in your instrument cluster are working, then i believe it's going to be a matter of three, maybe four wires to fix this problem.
your speedo needs two signal wires coming from your transmission, one power supply from ignition and one wire out to the ecu.
time to consult your messed up usdm 95 240sx fsm.
(i wired up my jdm s14 cluster in my pre-historic ride using cluster wires from a '93 240sx, wire colors were all unmatched but i had the tach and speedo working!)

a note on vss sensor and speedo compatability.
i am not sure, so i'm just going to throw out this list for someone to chime in. (first and last are no-brainer)

sr vss sensor in sr 5 speed with jdm speedo.
sr vss sensor in ka 5 speed with jdm speedo.(rare)
ka vss sensor in sr 5 speed with jdm speedo.
ka vss sensor in ka 5 speed with jdm speedo.

sr vss sensor in sr 5 speed with usdm speedo.
sr vss sensor in ka 5 speed with usdm speedo.(rare)
ka vss sensor in sr 5 speed with usdm speedo.
ka vss sensor in ka 5 speed with usdm speedo.

thecmv
04-20-2002, 04:23 PM
i wired the 2 wires from the speed sensor staight up to the guage cluster. the red and red/ yellow i believe. either the wires on the cluster is incorrect or the speed sensor is bad. Any one with s14 swaps get the speedo to work? how did u hook it up?

SRFiveTen
04-20-2002, 09:54 PM
Originally posted by thecmv:
i wired the 2 wires from the speed sensor staight up to the guage cluster. the red and red/ yellow i believe. either the wires on the cluster is incorrect or the speed sensor is bad. Any one with s14 swaps get the speedo to work? how did u hook it up?<font size="2" face="Verdana, Arial[/img]chris, you've come this far, vss isn't that difficult.

if fsm cannot be trusted, pull your cluster out of the dash and study the wires & trace on the back.
four attachment screws for the speedo make contact with traces (on jdm s14 cluster, for sure), two of them are for vss input, one for feeding ecu and another is for power. follow each trace to harness coupler, you can figure out which wires you need to pick out from there on.

one wire that used to feed the ka ecu with vss from your speedo must now be routed to yellow/green vss input wire for your sr ecu.

thecmv
04-21-2002, 12:30 PM
chuck,

i wil try to hook the seepdo up this week, it does not really explain if i turn up the boost the it starts bogging around 4000 rpms.

jeremiah
04-21-2002, 02:00 PM
my car did exactly the same thing as yours. it would be fine in 1st then every other gear past 5-6 would just bog. blew my mind for a week. What happened on mine was the intercooler pipe was blowing off the throttle body and then sucking back on once i was off the turbo.
maybe this is your prob too
-Jeremiah jordan

thecmv
04-21-2002, 02:02 PM
your t/b was loose as in not tightened?

jeremiah
04-21-2002, 05:08 PM
no the rubber intercooler pipe thing that y's off at the throttle body, the clamp was on crooked and the bottow half would blow open. You might want to check all the intercooler piping. I would floor it and the rpm's would barely move.
-Jeremiah

**DONOTDELETE**
04-22-2002, 07:53 AM
I feel your pain thecmv. I have a 89 coupe with sr swap no SAFc,with stock boost, went to the drags last night and the exact same thing happend to me. 1st gear is fine, but 2nd, 3rd, and 4th bogged out around 5000 RPM. Just barely beat a Mitsu. Eclipse(5th gear saved my butt) on my first run. Got spanked by a Toyota MR2 running 8.5psi of supercharged boost on my second run. I thought it would be better to take it easy since this was the first time dragging with the SR. Still scratching my head about the bogging out thing? I can see 1bad180sx point though when it comes to the Airflow Meter. SRfiveten, what exactly is the CEL and VSS maybe I can check it out on my 89 coupe and shed some light on the problem?

We'll see what happens
infin89 http://www.freshalloy.com/

SRFiveTen
04-22-2002, 10:18 AM
Originally posted by infin89:
what exactly is the CEL and VSS ?<font size="2" face="Verdana, Arial[/img]C.E.L. = check engine light, i don't know for sure if '89 dash had that,,, my '72 sure didn't.

V.S.S. = vehicle speed sensor.

89SX
04-22-2002, 09:49 PM
Yea, I reset it by putting 12 volts to the red-green wire for 2 seconds. So now the only code I get is for the Temp sensor Code 13. I changed my spark plugs and now the car is sputtering all the time. I can't cruise, and under hard acceleration it sputters then too. Who knows. I used BKR6E's gapped to .028. I'm getting really tired of the whole, not running correctly deal. Has anyone taken out there temp sensor before? I'm running into clearance issues on the socket's i'm using with them hitting the electrical connector on the dual pin plug. I'm gonna see if Craftsman has a socket that will fit. If I could get a socket that would fit I wouldn't have to take off the whole aluminum piece the two temp sensor's are attached too. Any info would be appreciated. Yes, I do have a S13 SR with SR ecu in an 89 coupe.

89SX
04-22-2002, 11:29 PM
I have an 89 coupe. It definately does not have a check engine light. At least mine's that way.

SRFiveTen
04-22-2002, 11:51 PM
Originally posted by 89SX:
I have an 89 coupe. It definately does not have a check engine light. At least mine's that way.<font size="2" face="Verdana, Arial[/img]if you want to, you can have one rigged up like i did, but your ecu for s13 sr20det(that's what you have, i presume) should have a red l.e.d. on the side for diagnosis.

thecmv has late s14 sr20det and his ecu doesn't have the l.e.d., so he needed to hook up the one on his dash.

**DONOTDELETE**
04-23-2002, 07:51 AM
I have the same problem in my 240, i dont have an sr motor but i have a ka24e turbo and it does the same thing. It only does it when the speedo does not work, so i am guessing the problem can be linked to this. Almost like the ecu thinks you are hitting top speed and cuts fuel.

Phil

thecmv
04-24-2002, 01:57 PM
i finally got my speedo to work.
same problem.
so i decided to buy new plugs.
that helped it out a little, it still bogs, but it slowly moves to redline. i tried to turn up the boost to .6 bar and bam it dies at 4000. so i am goign to try to put in a new maf.

**DONOTDELETE**
04-24-2002, 02:00 PM
What spark plugs are you using? You should be using NGK's for a 300zx twin turbo. Also, they might be fouled. That would be the first place I would check. The second place I would check is to see that your vacuum lines are all hooked up right.

thecmv
04-24-2002, 02:16 PM
i jsut got some denso pf16r11 from a 300zx
autozone was out of the ngk so i had to get these. my previous plugs were the ngk's.

**DONOTDELETE**
04-24-2002, 02:23 PM
just go to the nissan dealership and get the ngk's. I think it was like $30-$40 for the set of four from the dealer by me. I had the same problem as you and when I put the 300zx twin turbo plugs in, it fixed it right up. My other plugs were shorter and the spark wasnt down in the cylender far enough. I think that is the same problem you are having.

89SX
04-24-2002, 03:41 PM
Someone on here posted they had success with the BK6RE's so that's what I bought. I'm going to try changing my water temp sensor. I'll try going to nissan and buying their 300ZX TT plugs. Kinda funny since I'll only need 4. Last time I got the SR20DE plugs they gave me autolites!!! Sigh... Maybe that is my problem though, since after I changed plugs it has only gotten worse. Didn't even think to really compare the two plugs to eachother. What plugs are you guys using again?